Date: 2025-03-29T05:58:24+00:00

Actual source code: dm.c

      1: #include <petscvec.h>
      2: #include <petsc/private/dmimpl.h>
      3: #include <petsc/private/dmlabelimpl.h>
      4: #include <petsc/private/petscdsimpl.h>
      5: #include <petscdmplex.h>
      6: #include <petscdmceed.h>
      7: #include <petscdmfield.h>
      8: #include <petscsf.h>
      9: #include <petscds.h>

     11: #ifdef PETSC_HAVE_LIBCEED
     12: #include <petscfeceed.h>
     13: #endif

     15: PetscClassId DM_CLASSID;
     16: PetscClassId DMLABEL_CLASSID;
     17: PetscLogEvent DM_Convert, DM_GlobalToLocal, DM_LocalToGlobal, DM_LocalToLocal, DM_LocatePoints, DM_Coarsen, DM_Refine, DM_CreateInterpolation, DM_CreateRestriction, DM_CreateInjection, DM_CreateMatrix, DM_CreateMassMatrix, DM_Load, DM_View, DM_AdaptInterpolator, DM_ProjectFunction;

     19: const char *const DMBoundaryTypes[]          = {"NONE", "GHOSTED", "MIRROR", "PERIODIC", "TWIST", "DMBoundaryType", "DM_BOUNDARY_", NULL};
     20: const char *const DMBoundaryConditionTypes[] = {"INVALID", "ESSENTIAL", "NATURAL", "INVALID", "INVALID", "ESSENTIAL_FIELD", "NATURAL_FIELD", "INVALID", "INVALID", "ESSENTIAL_BD_FIELD", "NATURAL_RIEMANN", "DMBoundaryConditionType", "DM_BC_", NULL};
     21: const char *const DMBlockingTypes[]          = {"TOPOLOGICAL_POINT", "FIELD_NODE", "DMBlockingType", "DM_BLOCKING_", NULL};
     22: const char *const DMPolytopeTypes[] =
     23:   {"vertex",  "segment",      "tensor_segment", "triangle", "quadrilateral",  "tensor_quad",  "tetrahedron", "hexahedron", "triangular_prism", "tensor_triangular_prism", "tensor_quadrilateral_prism", "pyramid", "FV_ghost_cell", "interior_ghost_cell",
     24:    "unknown", "unknown_cell", "unknown_face",   "invalid",  "DMPolytopeType", "DM_POLYTOPE_", NULL};
     25: const char *const DMCopyLabelsModes[] = {"replace", "keep", "fail", "DMCopyLabelsMode", "DM_COPY_LABELS_", NULL};

     27: /*@
     28:   DMCreate - Creates an empty `DM` object. `DM`s are the abstract objects in PETSc that mediate between meshes and discretizations and the
     29:   algebraic solvers, time integrators, and optimization algorithms in PETSc.

     31:   Collective

     33:   Input Parameter:
     34: . comm - The communicator for the `DM` object

     36:   Output Parameter:
     37: . dm - The `DM` object

     39:   Level: beginner

     41:   Notes:
     42:   See `DMType` for a brief summary of available `DM`.

     44:   The type must then be set with `DMSetType()`. If you never call `DMSetType()` it will generate an
     45:   error when you try to use the `dm`.

     47:   `DM` is an orphan initialism or orphan acronym, the letters have no meaning and never did.

     49: .seealso: [](ch_dmbase), `DM`, `DMSetType()`, `DMType`, `DMDACreate()`, `DMDA`, `DMSLICED`, `DMCOMPOSITE`, `DMPLEX`, `DMMOAB`, `DMNETWORK`
     50: @*/
     51: PetscErrorCode DMCreate(MPI_Comm comm, DM *dm)
     52: {
     53:   DM      v;
     54:   PetscDS ds;

     56:   PetscFunctionBegin;
     57:   PetscAssertPointer(dm, 2);

     59:   PetscCall(DMInitializePackage());
     60:   PetscCall(PetscHeaderCreate(v, DM_CLASSID, "DM", "Distribution Manager", "DM", comm, DMDestroy, DMView));
     61:   ((PetscObject)v)->non_cyclic_references = &DMCountNonCyclicReferences;
     62:   v->setupcalled                          = PETSC_FALSE;
     63:   v->setfromoptionscalled                 = PETSC_FALSE;
     64:   v->ltogmap                              = NULL;
     65:   v->bind_below                           = 0;
     66:   v->bs                                   = 1;
     67:   v->coloringtype                         = IS_COLORING_GLOBAL;
     68:   PetscCall(PetscSFCreate(comm, &v->sf));
     69:   PetscCall(PetscSFCreate(comm, &v->sectionSF));
     70:   v->labels                    = NULL;
     71:   v->adjacency[0]              = PETSC_FALSE;
     72:   v->adjacency[1]              = PETSC_TRUE;
     73:   v->depthLabel                = NULL;
     74:   v->celltypeLabel             = NULL;
     75:   v->localSection              = NULL;
     76:   v->globalSection             = NULL;
     77:   v->defaultConstraint.section = NULL;
     78:   v->defaultConstraint.mat     = NULL;
     79:   v->defaultConstraint.bias    = NULL;
     80:   v->coordinates[0].dim        = PETSC_DEFAULT;
     81:   v->coordinates[1].dim        = PETSC_DEFAULT;
     82:   v->sparseLocalize            = PETSC_TRUE;
     83:   v->dim                       = PETSC_DETERMINE;
     84:   {
     85:     PetscInt i;
     86:     for (i = 0; i < 10; ++i) {
     87:       v->nullspaceConstructors[i]     = NULL;
     88:       v->nearnullspaceConstructors[i] = NULL;
     89:     }
     90:   }
     91:   PetscCall(PetscDSCreate(PETSC_COMM_SELF, &ds));
     92:   PetscCall(DMSetRegionDS(v, NULL, NULL, ds, NULL));
     93:   PetscCall(PetscDSDestroy(&ds));
     94:   PetscCall(PetscHMapAuxCreate(&v->auxData));
     95:   v->dmBC              = NULL;
     96:   v->coarseMesh        = NULL;
     97:   v->outputSequenceNum = -1;
     98:   v->outputSequenceVal = 0.0;
     99:   PetscCall(DMSetVecType(v, VECSTANDARD));
    100:   PetscCall(DMSetMatType(v, MATAIJ));

    102:   *dm = v;
    103:   PetscFunctionReturn(PETSC_SUCCESS);
    104: }

    106: /*@
    107:   DMClone - Creates a `DM` object with the same topology as the original.

    109:   Collective

    111:   Input Parameter:
    112: . dm - The original `DM` object

    114:   Output Parameter:
    115: . newdm - The new `DM` object

    117:   Level: beginner

    119:   Notes:
    120:   For some `DM` implementations this is a shallow clone, the result of which may share (reference counted) information with its parent. For example,
    121:   `DMClone()` applied to a `DMPLEX` object will result in a new `DMPLEX` that shares the topology with the original `DMPLEX`. It does not
    122:   share the `PetscSection` of the original `DM`.

    124:   The clone is considered set up if the original has been set up.

    126:   Use `DMConvert()` for a general way to create new `DM` from a given `DM`

    128: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMCreate()`, `DMSetType()`, `DMSetLocalSection()`, `DMSetGlobalSection()`, `DMPLEX`, `DMConvert()`
    129: @*/
    130: PetscErrorCode DMClone(DM dm, DM *newdm)
    131: {
    132:   PetscSF              sf;
    133:   Vec                  coords;
    134:   void                *ctx;
    135:   MatOrderingType      otype;
    136:   DMReorderDefaultFlag flg;
    137:   PetscInt             dim, cdim, i;

    139:   PetscFunctionBegin;
    141:   PetscAssertPointer(newdm, 2);
    142:   PetscCall(DMCreate(PetscObjectComm((PetscObject)dm), newdm));
    143:   PetscCall(DMCopyLabels(dm, *newdm, PETSC_COPY_VALUES, PETSC_TRUE, DM_COPY_LABELS_FAIL));
    144:   (*newdm)->leveldown     = dm->leveldown;
    145:   (*newdm)->levelup       = dm->levelup;
    146:   (*newdm)->prealloc_only = dm->prealloc_only;
    147:   (*newdm)->prealloc_skip = dm->prealloc_skip;
    148:   PetscCall(PetscFree((*newdm)->vectype));
    149:   PetscCall(PetscStrallocpy(dm->vectype, (char **)&(*newdm)->vectype));
    150:   PetscCall(PetscFree((*newdm)->mattype));
    151:   PetscCall(PetscStrallocpy(dm->mattype, (char **)&(*newdm)->mattype));
    152:   PetscCall(DMGetDimension(dm, &dim));
    153:   PetscCall(DMSetDimension(*newdm, dim));
    154:   PetscTryTypeMethod(dm, clone, newdm);
    155:   (*newdm)->setupcalled = dm->setupcalled;
    156:   PetscCall(DMGetPointSF(dm, &sf));
    157:   PetscCall(DMSetPointSF(*newdm, sf));
    158:   PetscCall(DMGetApplicationContext(dm, &ctx));
    159:   PetscCall(DMSetApplicationContext(*newdm, ctx));
    160:   PetscCall(DMReorderSectionGetDefault(dm, &flg));
    161:   PetscCall(DMReorderSectionSetDefault(*newdm, flg));
    162:   PetscCall(DMReorderSectionGetType(dm, &otype));
    163:   PetscCall(DMReorderSectionSetType(*newdm, otype));
    164:   for (i = 0; i < 2; ++i) {
    165:     if (dm->coordinates[i].dm) {
    166:       DM           ncdm;
    167:       PetscSection cs;
    168:       PetscInt     pEnd = -1, pEndMax = -1;

    170:       PetscCall(DMGetLocalSection(dm->coordinates[i].dm, &cs));
    171:       if (cs) PetscCall(PetscSectionGetChart(cs, NULL, &pEnd));
    172:       PetscCallMPI(MPIU_Allreduce(&pEnd, &pEndMax, 1, MPIU_INT, MPI_MAX, PetscObjectComm((PetscObject)dm)));
    173:       if (pEndMax >= 0) {
    174:         PetscCall(DMClone(dm->coordinates[i].dm, &ncdm));
    175:         PetscCall(DMCopyDisc(dm->coordinates[i].dm, ncdm));
    176:         PetscCall(DMSetLocalSection(ncdm, cs));
    177:         if (dm->coordinates[i].dm->periodic.setup) {
    178:           ncdm->periodic.setup = dm->coordinates[i].dm->periodic.setup;
    179:           PetscCall(ncdm->periodic.setup(ncdm));
    180:         }
    181:         if (i) PetscCall(DMSetCellCoordinateDM(*newdm, ncdm));
    182:         else PetscCall(DMSetCoordinateDM(*newdm, ncdm));
    183:         PetscCall(DMDestroy(&ncdm));
    184:       }
    185:     }
    186:   }
    187:   PetscCall(DMGetCoordinateDim(dm, &cdim));
    188:   PetscCall(DMSetCoordinateDim(*newdm, cdim));
    189:   PetscCall(DMGetCoordinatesLocal(dm, &coords));
    190:   if (coords) {
    191:     PetscCall(DMSetCoordinatesLocal(*newdm, coords));
    192:   } else {
    193:     PetscCall(DMGetCoordinates(dm, &coords));
    194:     if (coords) PetscCall(DMSetCoordinates(*newdm, coords));
    195:   }
    196:   PetscCall(DMGetCellCoordinatesLocal(dm, &coords));
    197:   if (coords) {
    198:     PetscCall(DMSetCellCoordinatesLocal(*newdm, coords));
    199:   } else {
    200:     PetscCall(DMGetCellCoordinates(dm, &coords));
    201:     if (coords) PetscCall(DMSetCellCoordinates(*newdm, coords));
    202:   }
    203:   {
    204:     const PetscReal *maxCell, *Lstart, *L;

    206:     PetscCall(DMGetPeriodicity(dm, &maxCell, &Lstart, &L));
    207:     PetscCall(DMSetPeriodicity(*newdm, maxCell, Lstart, L));
    208:   }
    209:   {
    210:     PetscBool useCone, useClosure;

    212:     PetscCall(DMGetAdjacency(dm, PETSC_DEFAULT, &useCone, &useClosure));
    213:     PetscCall(DMSetAdjacency(*newdm, PETSC_DEFAULT, useCone, useClosure));
    214:   }
    215:   PetscFunctionReturn(PETSC_SUCCESS);
    216: }

    218: /*@
    219:   DMSetVecType - Sets the type of vector to be created with `DMCreateLocalVector()` and `DMCreateGlobalVector()`

    221:   Logically Collective

    223:   Input Parameters:
    224: + dm    - initial distributed array
    225: - ctype - the vector type, for example `VECSTANDARD`, `VECCUDA`, or `VECVIENNACL`

    227:   Options Database Key:
    228: . -dm_vec_type ctype - the type of vector to create

    230:   Level: intermediate

    232: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMDestroy()`, `DMDAInterpolationType`, `VecType`, `DMGetVecType()`, `DMSetMatType()`, `DMGetMatType()`,
    233:           `VECSTANDARD`, `VECCUDA`, `VECVIENNACL`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`
    234: @*/
    235: PetscErrorCode DMSetVecType(DM dm, VecType ctype)
    236: {
    237:   char *tmp;

    239:   PetscFunctionBegin;
    241:   PetscAssertPointer(ctype, 2);
    242:   tmp = (char *)dm->vectype;
    243:   PetscCall(PetscStrallocpy(ctype, (char **)&dm->vectype));
    244:   PetscCall(PetscFree(tmp));
    245:   PetscFunctionReturn(PETSC_SUCCESS);
    246: }

    248: /*@
    249:   DMGetVecType - Gets the type of vector created with `DMCreateLocalVector()` and `DMCreateGlobalVector()`

    251:   Logically Collective

    253:   Input Parameter:
    254: . da - initial distributed array

    256:   Output Parameter:
    257: . ctype - the vector type

    259:   Level: intermediate

    261: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMDestroy()`, `DMDAInterpolationType`, `VecType`, `DMSetMatType()`, `DMGetMatType()`, `DMSetVecType()`
    262: @*/
    263: PetscErrorCode DMGetVecType(DM da, VecType *ctype)
    264: {
    265:   PetscFunctionBegin;
    267:   *ctype = da->vectype;
    268:   PetscFunctionReturn(PETSC_SUCCESS);
    269: }

    271: /*@
    272:   VecGetDM - Gets the `DM` defining the data layout of the vector

    274:   Not Collective

    276:   Input Parameter:
    277: . v - The `Vec`

    279:   Output Parameter:
    280: . dm - The `DM`

    282:   Level: intermediate

    284:   Note:
    285:   A `Vec` may not have a `DM` associated with it.

    287: .seealso: [](ch_dmbase), `DM`, `VecSetDM()`, `DMGetLocalVector()`, `DMGetGlobalVector()`, `DMSetVecType()`
    288: @*/
    289: PetscErrorCode VecGetDM(Vec v, DM *dm)
    290: {
    291:   PetscFunctionBegin;
    293:   PetscAssertPointer(dm, 2);
    294:   PetscCall(PetscObjectQuery((PetscObject)v, "__PETSc_dm", (PetscObject *)dm));
    295:   PetscFunctionReturn(PETSC_SUCCESS);
    296: }

    298: /*@
    299:   VecSetDM - Sets the `DM` defining the data layout of the vector.

    301:   Not Collective

    303:   Input Parameters:
    304: + v  - The `Vec`
    305: - dm - The `DM`

    307:   Level: developer

    309:   Notes:
    310:   This is rarely used, generally one uses `DMGetLocalVector()` or  `DMGetGlobalVector()` to create a vector associated with a given `DM`

    312:   This is NOT the same as `DMCreateGlobalVector()` since it does not change the view methods or perform other customization, but merely sets the `DM` member.

    314: .seealso: [](ch_dmbase), `DM`, `VecGetDM()`, `DMGetLocalVector()`, `DMGetGlobalVector()`, `DMSetVecType()`
    315: @*/
    316: PetscErrorCode VecSetDM(Vec v, DM dm)
    317: {
    318:   PetscFunctionBegin;
    321:   PetscCall(PetscObjectCompose((PetscObject)v, "__PETSc_dm", (PetscObject)dm));
    322:   PetscFunctionReturn(PETSC_SUCCESS);
    323: }

    325: /*@
    326:   DMSetISColoringType - Sets the type of coloring, `IS_COLORING_GLOBAL` or `IS_COLORING_LOCAL` that is created by the `DM`

    328:   Logically Collective

    330:   Input Parameters:
    331: + dm    - the `DM` context
    332: - ctype - the matrix type

    334:   Options Database Key:
    335: . -dm_is_coloring_type - global or local

    337:   Level: intermediate

    339: .seealso: [](ch_dmbase), `DM`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `MatType`, `DMGetMatType()`,
    340:           `DMGetISColoringType()`, `ISColoringType`, `IS_COLORING_GLOBAL`, `IS_COLORING_LOCAL`
    341: @*/
    342: PetscErrorCode DMSetISColoringType(DM dm, ISColoringType ctype)
    343: {
    344:   PetscFunctionBegin;
    346:   dm->coloringtype = ctype;
    347:   PetscFunctionReturn(PETSC_SUCCESS);
    348: }

    350: /*@
    351:   DMGetISColoringType - Gets the type of coloring, `IS_COLORING_GLOBAL` or `IS_COLORING_LOCAL` that is created by the `DM`

    353:   Logically Collective

    355:   Input Parameter:
    356: . dm - the `DM` context

    358:   Output Parameter:
    359: . ctype - the matrix type

    361:   Options Database Key:
    362: . -dm_is_coloring_type - global or local

    364:   Level: intermediate

    366: .seealso: [](ch_dmbase), `DM`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `MatType`, `DMGetMatType()`,
    367:           `ISColoringType`, `IS_COLORING_GLOBAL`, `IS_COLORING_LOCAL`
    368: @*/
    369: PetscErrorCode DMGetISColoringType(DM dm, ISColoringType *ctype)
    370: {
    371:   PetscFunctionBegin;
    373:   *ctype = dm->coloringtype;
    374:   PetscFunctionReturn(PETSC_SUCCESS);
    375: }

    377: /*@
    378:   DMSetMatType - Sets the type of matrix created with `DMCreateMatrix()`

    380:   Logically Collective

    382:   Input Parameters:
    383: + dm    - the `DM` context
    384: - ctype - the matrix type, for example `MATMPIAIJ`

    386:   Options Database Key:
    387: . -dm_mat_type ctype - the type of the matrix to create, for example mpiaij

    389:   Level: intermediate

    391: .seealso: [](ch_dmbase), `DM`, `MatType`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `DMGetMatType()`, `DMCreateGlobalVector()`, `DMCreateLocalVector()`
    392: @*/
    393: PetscErrorCode DMSetMatType(DM dm, MatType ctype)
    394: {
    395:   char *tmp;

    397:   PetscFunctionBegin;
    399:   PetscAssertPointer(ctype, 2);
    400:   tmp = (char *)dm->mattype;
    401:   PetscCall(PetscStrallocpy(ctype, (char **)&dm->mattype));
    402:   PetscCall(PetscFree(tmp));
    403:   PetscFunctionReturn(PETSC_SUCCESS);
    404: }

    406: /*@
    407:   DMGetMatType - Gets the type of matrix that would be created with `DMCreateMatrix()`

    409:   Logically Collective

    411:   Input Parameter:
    412: . dm - the `DM` context

    414:   Output Parameter:
    415: . ctype - the matrix type

    417:   Level: intermediate

    419: .seealso: [](ch_dmbase), `DM`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixPreallocateOnly()`, `MatType`, `DMSetMatType()`
    420: @*/
    421: PetscErrorCode DMGetMatType(DM dm, MatType *ctype)
    422: {
    423:   PetscFunctionBegin;
    425:   *ctype = dm->mattype;
    426:   PetscFunctionReturn(PETSC_SUCCESS);
    427: }

    429: /*@
    430:   MatGetDM - Gets the `DM` defining the data layout of the matrix

    432:   Not Collective

    434:   Input Parameter:
    435: . A - The `Mat`

    437:   Output Parameter:
    438: . dm - The `DM`

    440:   Level: intermediate

    442:   Note:
    443:   A matrix may not have a `DM` associated with it

    445:   Developer Note:
    446:   Since the `Mat` class doesn't know about the `DM` class the `DM` object is associated with the `Mat` through a `PetscObjectCompose()` operation

    448: .seealso: [](ch_dmbase), `DM`, `MatSetDM()`, `DMCreateMatrix()`, `DMSetMatType()`
    449: @*/
    450: PetscErrorCode MatGetDM(Mat A, DM *dm)
    451: {
    452:   PetscFunctionBegin;
    454:   PetscAssertPointer(dm, 2);
    455:   PetscCall(PetscObjectQuery((PetscObject)A, "__PETSc_dm", (PetscObject *)dm));
    456:   PetscFunctionReturn(PETSC_SUCCESS);
    457: }

    459: /*@
    460:   MatSetDM - Sets the `DM` defining the data layout of the matrix

    462:   Not Collective

    464:   Input Parameters:
    465: + A  - The `Mat`
    466: - dm - The `DM`

    468:   Level: developer

    470:   Note:
    471:   This is rarely used in practice, rather `DMCreateMatrix()` is used to create a matrix associated with a particular `DM`

    473:   Developer Note:
    474:   Since the `Mat` class doesn't know about the `DM` class the `DM` object is associated with
    475:   the `Mat` through a `PetscObjectCompose()` operation

    477: .seealso: [](ch_dmbase), `DM`, `MatGetDM()`, `DMCreateMatrix()`, `DMSetMatType()`
    478: @*/
    479: PetscErrorCode MatSetDM(Mat A, DM dm)
    480: {
    481:   PetscFunctionBegin;
    484:   PetscCall(PetscObjectCompose((PetscObject)A, "__PETSc_dm", (PetscObject)dm));
    485:   PetscFunctionReturn(PETSC_SUCCESS);
    486: }

    488: /*@
    489:   DMSetOptionsPrefix - Sets the prefix prepended to all option names when searching through the options database

    491:   Logically Collective

    493:   Input Parameters:
    494: + dm     - the `DM` context
    495: - prefix - the prefix to prepend

    497:   Level: advanced

    499:   Note:
    500:   A hyphen (-) must NOT be given at the beginning of the prefix name.
    501:   The first character of all runtime options is AUTOMATICALLY the hyphen.

    503: .seealso: [](ch_dmbase), `DM`, `PetscObjectSetOptionsPrefix()`, `DMSetFromOptions()`
    504: @*/
    505: PetscErrorCode DMSetOptionsPrefix(DM dm, const char prefix[])
    506: {
    507:   PetscFunctionBegin;
    509:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)dm, prefix));
    510:   if (dm->sf) PetscCall(PetscObjectSetOptionsPrefix((PetscObject)dm->sf, prefix));
    511:   if (dm->sectionSF) PetscCall(PetscObjectSetOptionsPrefix((PetscObject)dm->sectionSF, prefix));
    512:   PetscFunctionReturn(PETSC_SUCCESS);
    513: }

    515: /*@
    516:   DMAppendOptionsPrefix - Appends an additional string to an already existing prefix used for searching for
    517:   `DM` options in the options database.

    519:   Logically Collective

    521:   Input Parameters:
    522: + dm     - the `DM` context
    523: - prefix - the string to append to the current prefix

    525:   Level: advanced

    527:   Note:
    528:   If the `DM` does not currently have an options prefix then this value is used alone as the prefix as if `DMSetOptionsPrefix()` had been called.
    529:   A hyphen (-) must NOT be given at the beginning of the prefix name.
    530:   The first character of all runtime options is AUTOMATICALLY the hyphen.

    532: .seealso: [](ch_dmbase), `DM`, `DMSetOptionsPrefix()`, `DMGetOptionsPrefix()`, `PetscObjectAppendOptionsPrefix()`, `DMSetFromOptions()`
    533: @*/
    534: PetscErrorCode DMAppendOptionsPrefix(DM dm, const char prefix[])
    535: {
    536:   PetscFunctionBegin;
    538:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)dm, prefix));
    539:   PetscFunctionReturn(PETSC_SUCCESS);
    540: }

    542: /*@
    543:   DMGetOptionsPrefix - Gets the prefix used for searching for all
    544:   DM options in the options database.

    546:   Not Collective

    548:   Input Parameter:
    549: . dm - the `DM` context

    551:   Output Parameter:
    552: . prefix - pointer to the prefix string used is returned

    554:   Level: advanced

    556:   Fortran Note:
    557:   Pass in a string 'prefix' of
    558:   sufficient length to hold the prefix.

    560: .seealso: [](ch_dmbase), `DM`, `DMSetOptionsPrefix()`, `DMAppendOptionsPrefix()`, `DMSetFromOptions()`
    561: @*/
    562: PetscErrorCode DMGetOptionsPrefix(DM dm, const char *prefix[])
    563: {
    564:   PetscFunctionBegin;
    566:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)dm, prefix));
    567:   PetscFunctionReturn(PETSC_SUCCESS);
    568: }

    570: static PetscErrorCode DMCountNonCyclicReferences_Internal(DM dm, PetscBool recurseCoarse, PetscBool recurseFine, PetscInt *ncrefct)
    571: {
    572:   PetscInt refct = ((PetscObject)dm)->refct;

    574:   PetscFunctionBegin;
    575:   *ncrefct = 0;
    576:   if (dm->coarseMesh && dm->coarseMesh->fineMesh == dm) {
    577:     refct--;
    578:     if (recurseCoarse) {
    579:       PetscInt coarseCount;

    581:       PetscCall(DMCountNonCyclicReferences_Internal(dm->coarseMesh, PETSC_TRUE, PETSC_FALSE, &coarseCount));
    582:       refct += coarseCount;
    583:     }
    584:   }
    585:   if (dm->fineMesh && dm->fineMesh->coarseMesh == dm) {
    586:     refct--;
    587:     if (recurseFine) {
    588:       PetscInt fineCount;

    590:       PetscCall(DMCountNonCyclicReferences_Internal(dm->fineMesh, PETSC_FALSE, PETSC_TRUE, &fineCount));
    591:       refct += fineCount;
    592:     }
    593:   }
    594:   *ncrefct = refct;
    595:   PetscFunctionReturn(PETSC_SUCCESS);
    596: }

    598: /* Generic wrapper for DMCountNonCyclicReferences_Internal() */
    599: PetscErrorCode DMCountNonCyclicReferences(PetscObject dm, PetscInt *ncrefct)
    600: {
    601:   PetscFunctionBegin;
    602:   PetscCall(DMCountNonCyclicReferences_Internal((DM)dm, PETSC_TRUE, PETSC_TRUE, ncrefct));
    603:   PetscFunctionReturn(PETSC_SUCCESS);
    604: }

    606: PetscErrorCode DMDestroyLabelLinkList_Internal(DM dm)
    607: {
    608:   DMLabelLink next = dm->labels;

    610:   PetscFunctionBegin;
    611:   /* destroy the labels */
    612:   while (next) {
    613:     DMLabelLink tmp = next->next;

    615:     if (next->label == dm->depthLabel) dm->depthLabel = NULL;
    616:     if (next->label == dm->celltypeLabel) dm->celltypeLabel = NULL;
    617:     PetscCall(DMLabelDestroy(&next->label));
    618:     PetscCall(PetscFree(next));
    619:     next = tmp;
    620:   }
    621:   dm->labels = NULL;
    622:   PetscFunctionReturn(PETSC_SUCCESS);
    623: }

    625: static PetscErrorCode DMDestroyCoordinates_Private(DMCoordinates *c)
    626: {
    627:   PetscFunctionBegin;
    628:   c->dim = PETSC_DEFAULT;
    629:   PetscCall(DMDestroy(&c->dm));
    630:   PetscCall(VecDestroy(&c->x));
    631:   PetscCall(VecDestroy(&c->xl));
    632:   PetscCall(DMFieldDestroy(&c->field));
    633:   PetscFunctionReturn(PETSC_SUCCESS);
    634: }

    636: /*@
    637:   DMDestroy - Destroys a `DM`.

    639:   Collective

    641:   Input Parameter:
    642: . dm - the `DM` object to destroy

    644:   Level: developer

    646: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMType`, `DMSetType()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`
    647: @*/
    648: PetscErrorCode DMDestroy(DM *dm)
    649: {
    650:   PetscInt cnt;

    652:   PetscFunctionBegin;
    653:   if (!*dm) PetscFunctionReturn(PETSC_SUCCESS);

    656:   /* count all non-cyclic references in the doubly-linked list of coarse<->fine meshes */
    657:   PetscCall(DMCountNonCyclicReferences_Internal(*dm, PETSC_TRUE, PETSC_TRUE, &cnt));
    658:   --((PetscObject)*dm)->refct;
    659:   if (--cnt > 0) {
    660:     *dm = NULL;
    661:     PetscFunctionReturn(PETSC_SUCCESS);
    662:   }
    663:   if (((PetscObject)*dm)->refct < 0) PetscFunctionReturn(PETSC_SUCCESS);
    664:   ((PetscObject)*dm)->refct = 0;

    666:   PetscCall(DMClearGlobalVectors(*dm));
    667:   PetscCall(DMClearLocalVectors(*dm));
    668:   PetscCall(DMClearNamedGlobalVectors(*dm));
    669:   PetscCall(DMClearNamedLocalVectors(*dm));

    671:   /* Destroy the list of hooks */
    672:   {
    673:     DMCoarsenHookLink link, next;
    674:     for (link = (*dm)->coarsenhook; link; link = next) {
    675:       next = link->next;
    676:       PetscCall(PetscFree(link));
    677:     }
    678:     (*dm)->coarsenhook = NULL;
    679:   }
    680:   {
    681:     DMRefineHookLink link, next;
    682:     for (link = (*dm)->refinehook; link; link = next) {
    683:       next = link->next;
    684:       PetscCall(PetscFree(link));
    685:     }
    686:     (*dm)->refinehook = NULL;
    687:   }
    688:   {
    689:     DMSubDomainHookLink link, next;
    690:     for (link = (*dm)->subdomainhook; link; link = next) {
    691:       next = link->next;
    692:       PetscCall(PetscFree(link));
    693:     }
    694:     (*dm)->subdomainhook = NULL;
    695:   }
    696:   {
    697:     DMGlobalToLocalHookLink link, next;
    698:     for (link = (*dm)->gtolhook; link; link = next) {
    699:       next = link->next;
    700:       PetscCall(PetscFree(link));
    701:     }
    702:     (*dm)->gtolhook = NULL;
    703:   }
    704:   {
    705:     DMLocalToGlobalHookLink link, next;
    706:     for (link = (*dm)->ltoghook; link; link = next) {
    707:       next = link->next;
    708:       PetscCall(PetscFree(link));
    709:     }
    710:     (*dm)->ltoghook = NULL;
    711:   }
    712:   /* Destroy the work arrays */
    713:   {
    714:     DMWorkLink link, next;
    715:     PetscCheck(!(*dm)->workout, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Work array still checked out %p %p", (void *)(*dm)->workout, (*dm)->workout->mem);
    716:     for (link = (*dm)->workin; link; link = next) {
    717:       next = link->next;
    718:       PetscCall(PetscFree(link->mem));
    719:       PetscCall(PetscFree(link));
    720:     }
    721:     (*dm)->workin = NULL;
    722:   }
    723:   /* destroy the labels */
    724:   PetscCall(DMDestroyLabelLinkList_Internal(*dm));
    725:   /* destroy the fields */
    726:   PetscCall(DMClearFields(*dm));
    727:   /* destroy the boundaries */
    728:   {
    729:     DMBoundary next = (*dm)->boundary;
    730:     while (next) {
    731:       DMBoundary b = next;

    733:       next = b->next;
    734:       PetscCall(PetscFree(b));
    735:     }
    736:   }

    738:   PetscCall(PetscObjectDestroy(&(*dm)->dmksp));
    739:   PetscCall(PetscObjectDestroy(&(*dm)->dmsnes));
    740:   PetscCall(PetscObjectDestroy(&(*dm)->dmts));

    742:   if ((*dm)->ctx && (*dm)->ctxdestroy) PetscCall((*(*dm)->ctxdestroy)(&(*dm)->ctx));
    743:   PetscCall(MatFDColoringDestroy(&(*dm)->fd));
    744:   PetscCall(ISLocalToGlobalMappingDestroy(&(*dm)->ltogmap));
    745:   PetscCall(PetscFree((*dm)->vectype));
    746:   PetscCall(PetscFree((*dm)->mattype));

    748:   PetscCall(PetscSectionDestroy(&(*dm)->localSection));
    749:   PetscCall(PetscSectionDestroy(&(*dm)->globalSection));
    750:   PetscCall(PetscFree((*dm)->reorderSectionType));
    751:   PetscCall(PetscLayoutDestroy(&(*dm)->map));
    752:   PetscCall(PetscSectionDestroy(&(*dm)->defaultConstraint.section));
    753:   PetscCall(MatDestroy(&(*dm)->defaultConstraint.mat));
    754:   PetscCall(PetscSFDestroy(&(*dm)->sf));
    755:   PetscCall(PetscSFDestroy(&(*dm)->sectionSF));
    756:   if ((*dm)->sfNatural) PetscCall(PetscSFDestroy(&(*dm)->sfNatural));
    757:   PetscCall(PetscObjectDereference((PetscObject)(*dm)->sfMigration));
    758:   PetscCall(DMClearAuxiliaryVec(*dm));
    759:   PetscCall(PetscHMapAuxDestroy(&(*dm)->auxData));
    760:   if ((*dm)->coarseMesh && (*dm)->coarseMesh->fineMesh == *dm) PetscCall(DMSetFineDM((*dm)->coarseMesh, NULL));

    762:   PetscCall(DMDestroy(&(*dm)->coarseMesh));
    763:   if ((*dm)->fineMesh && (*dm)->fineMesh->coarseMesh == *dm) PetscCall(DMSetCoarseDM((*dm)->fineMesh, NULL));
    764:   PetscCall(DMDestroy(&(*dm)->fineMesh));
    765:   PetscCall(PetscFree((*dm)->Lstart));
    766:   PetscCall(PetscFree((*dm)->L));
    767:   PetscCall(PetscFree((*dm)->maxCell));
    768:   PetscCall(DMDestroyCoordinates_Private(&(*dm)->coordinates[0]));
    769:   PetscCall(DMDestroyCoordinates_Private(&(*dm)->coordinates[1]));
    770:   if ((*dm)->transformDestroy) PetscCall((*(*dm)->transformDestroy)(*dm, (*dm)->transformCtx));
    771:   PetscCall(DMDestroy(&(*dm)->transformDM));
    772:   PetscCall(VecDestroy(&(*dm)->transform));
    773:   for (PetscInt i = 0; i < (*dm)->periodic.num_affines; i++) {
    774:     PetscCall(VecScatterDestroy(&(*dm)->periodic.affine_to_local[i]));
    775:     PetscCall(VecDestroy(&(*dm)->periodic.affine[i]));
    776:   }
    777:   if ((*dm)->periodic.num_affines > 0) PetscCall(PetscFree2((*dm)->periodic.affine_to_local, (*dm)->periodic.affine));

    779:   PetscCall(DMClearDS(*dm));
    780:   PetscCall(DMDestroy(&(*dm)->dmBC));
    781:   /* if memory was published with SAWs then destroy it */
    782:   PetscCall(PetscObjectSAWsViewOff((PetscObject)*dm));

    784:   PetscTryTypeMethod(*dm, destroy);
    785:   PetscCall(DMMonitorCancel(*dm));
    786:   PetscCall(DMCeedDestroy(&(*dm)->dmceed));
    787: #ifdef PETSC_HAVE_LIBCEED
    788:   PetscCallCEED(CeedElemRestrictionDestroy(&(*dm)->ceedERestrict));
    789:   PetscCallCEED(CeedDestroy(&(*dm)->ceed));
    790: #endif
    791:   /* We do not destroy (*dm)->data here so that we can reference count backend objects */
    792:   PetscCall(PetscHeaderDestroy(dm));
    793:   PetscFunctionReturn(PETSC_SUCCESS);
    794: }

    796: /*@
    797:   DMSetUp - sets up the data structures inside a `DM` object

    799:   Collective

    801:   Input Parameter:
    802: . dm - the `DM` object to setup

    804:   Level: intermediate

    806:   Note:
    807:   This is usually called after various parameter setting operations and `DMSetFromOptions()` are called on the `DM`

    809: .seealso: [](ch_dmbase), `DM`, `DMCreate()`, `DMSetType()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`
    810: @*/
    811: PetscErrorCode DMSetUp(DM dm)
    812: {
    813:   PetscFunctionBegin;
    815:   if (dm->setupcalled) PetscFunctionReturn(PETSC_SUCCESS);
    816:   PetscTryTypeMethod(dm, setup);
    817:   dm->setupcalled = PETSC_TRUE;
    818:   PetscFunctionReturn(PETSC_SUCCESS);
    819: }

    821: /*@
    822:   DMSetFromOptions - sets parameters in a `DM` from the options database

    824:   Collective

    826:   Input Parameter:
    827: . dm - the `DM` object to set options for

    829:   Options Database Keys:
    830: + -dm_preallocate_only                               - Only preallocate the matrix for `DMCreateMatrix()` and `DMCreateMassMatrix()`, but do not fill it with zeros
    831: . -dm_vec_type <type>                                - type of vector to create inside `DM`
    832: . -dm_mat_type <type>                                - type of matrix to create inside `DM`
    833: . -dm_is_coloring_type                               - <global or local>
    834: . -dm_bind_below <n>                                 - bind (force execution on CPU) for `Vec` and `Mat` objects with local size (number of vector entries or matrix rows) below n; currently only supported for `DMDA`
    835: . -dm_plex_option_phases <ph0_, ph1_, ...>           - List of prefixes for option processing phases
    836: . -dm_plex_filename <str>                            - File containing a mesh
    837: . -dm_plex_boundary_filename <str>                   - File containing a mesh boundary
    838: . -dm_plex_name <str>                                - Name of the mesh in the file
    839: . -dm_plex_shape <shape>                             - The domain shape, such as `BOX`, `SPHERE`, etc.
    840: . -dm_plex_cell <ct>                                 - Cell shape
    841: . -dm_plex_reference_cell_domain <bool>              - Use a reference cell domain
    842: . -dm_plex_dim <dim>                                 - Set the topological dimension
    843: . -dm_plex_simplex <bool>                            - `PETSC_TRUE` for simplex elements, `PETSC_FALSE` for tensor elements
    844: . -dm_plex_interpolate <bool>                        - `PETSC_TRUE` turns on topological interpolation (creating edges and faces)
    845: . -dm_plex_orient <bool>                             - `PETSC_TRUE` turns on topological orientation (flipping edges and faces)
    846: . -dm_plex_scale <sc>                                - Scale factor for mesh coordinates
    847: . -dm_coord_remap <bool>                             - Map coordinates using a function
    848: . -dm_plex_coordinate_dim <dim>                      - Change the coordinate dimension of a mesh (usually given with cdm_ prefix)
    849: . -dm_coord_map <mapname>                            - Select a builtin coordinate map
    850: . -dm_coord_map_params <p0,p1,p2,...>                - Set coordinate mapping parameters
    851: . -dm_plex_box_faces <m,n,p>                         - Number of faces along each dimension
    852: . -dm_plex_box_lower <x,y,z>                         - Specify lower-left-bottom coordinates for the box
    853: . -dm_plex_box_upper <x,y,z>                         - Specify upper-right-top coordinates for the box
    854: . -dm_plex_box_bd <bx,by,bz>                         - Specify the `DMBoundaryType` for each direction
    855: . -dm_plex_sphere_radius <r>                         - The sphere radius
    856: . -dm_plex_ball_radius <r>                           - Radius of the ball
    857: . -dm_plex_cylinder_bd <bz>                          - Boundary type in the z direction
    858: . -dm_plex_cylinder_num_wedges <n>                   - Number of wedges around the cylinder
    859: . -dm_plex_reorder <order>                           - Reorder the mesh using the specified algorithm
    860: . -dm_refine_pre <n>                                 - The number of refinements before distribution
    861: . -dm_refine_uniform_pre <bool>                      - Flag for uniform refinement before distribution
    862: . -dm_refine_volume_limit_pre <v>                    - The maximum cell volume after refinement before distribution
    863: . -dm_refine <n>                                     - The number of refinements after distribution
    864: . -dm_extrude <l>                                    - Activate extrusion and specify the number of layers to extrude
    865: . -dm_plex_transform_extrude_thickness <t>           - The total thickness of extruded layers
    866: . -dm_plex_transform_extrude_use_tensor <bool>       - Use tensor cells when extruding
    867: . -dm_plex_transform_extrude_symmetric <bool>        - Extrude layers symmetrically about the surface
    868: . -dm_plex_transform_extrude_normal <n0,...,nd>      - Specify the extrusion direction
    869: . -dm_plex_transform_extrude_thicknesses <t0,...,tl> - Specify thickness of each layer
    870: . -dm_plex_create_fv_ghost_cells                     - Flag to create finite volume ghost cells on the boundary
    871: . -dm_plex_fv_ghost_cells_label <name>               - Label name for ghost cells boundary
    872: . -dm_distribute <bool>                              - Flag to redistribute a mesh among processes
    873: . -dm_distribute_overlap <n>                         - The size of the overlap halo
    874: . -dm_plex_adj_cone <bool>                           - Set adjacency direction
    875: . -dm_plex_adj_closure <bool>                        - Set adjacency size
    876: . -dm_plex_use_ceed <bool>                           - Use LibCEED as the FEM backend
    877: . -dm_plex_check_symmetry                            - Check that the adjacency information in the mesh is symmetric - `DMPlexCheckSymmetry()`
    878: . -dm_plex_check_skeleton                            - Check that each cell has the correct number of vertices (only for homogeneous simplex or tensor meshes) - `DMPlexCheckSkeleton()`
    879: . -dm_plex_check_faces                               - Check that the faces of each cell give a vertex order this is consistent with what we expect from the cell type - `DMPlexCheckFaces()`
    880: . -dm_plex_check_geometry                            - Check that cells have positive volume - `DMPlexCheckGeometry()`
    881: . -dm_plex_check_pointsf                             - Check some necessary conditions for `PointSF` - `DMPlexCheckPointSF()`
    882: . -dm_plex_check_interface_cones                     - Check points on inter-partition interfaces have conforming order of cone points - `DMPlexCheckInterfaceCones()`
    883: - -dm_plex_check_all                                 - Perform all the checks above

    885:   Level: intermediate

    887:   Note:
    888:   For some `DMType` such as `DMDA` this cannot be called after `DMSetUp()` has been called.

    890: .seealso: [](ch_dmbase), `DM`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`,
    891:          `DMPlexCheckSymmetry()`, `DMPlexCheckSkeleton()`, `DMPlexCheckFaces()`, `DMPlexCheckGeometry()`, `DMPlexCheckPointSF()`, `DMPlexCheckInterfaceCones()`,
    892:          `DMSetOptionsPrefix()`, `DMType`, `DMPLEX`, `DMDA`, `DMSetUp()`
    893: @*/
    894: PetscErrorCode DMSetFromOptions(DM dm)
    895: {
    896:   char      typeName[256];
    897:   PetscBool flg;

    899:   PetscFunctionBegin;
    901:   dm->setfromoptionscalled = PETSC_TRUE;
    902:   if (dm->sf) PetscCall(PetscSFSetFromOptions(dm->sf));
    903:   if (dm->sectionSF) PetscCall(PetscSFSetFromOptions(dm->sectionSF));
    904:   if (dm->coordinates[0].dm) PetscCall(DMSetFromOptions(dm->coordinates[0].dm));
    905:   PetscObjectOptionsBegin((PetscObject)dm);
    906:   PetscCall(PetscOptionsBool("-dm_preallocate_only", "only preallocate matrix, but do not set column indices", "DMSetMatrixPreallocateOnly", dm->prealloc_only, &dm->prealloc_only, NULL));
    907:   PetscCall(PetscOptionsFList("-dm_vec_type", "Vector type used for created vectors", "DMSetVecType", VecList, dm->vectype, typeName, 256, &flg));
    908:   if (flg) PetscCall(DMSetVecType(dm, typeName));
    909:   PetscCall(PetscOptionsFList("-dm_mat_type", "Matrix type used for created matrices", "DMSetMatType", MatList, dm->mattype ? dm->mattype : typeName, typeName, sizeof(typeName), &flg));
    910:   if (flg) PetscCall(DMSetMatType(dm, typeName));
    911:   PetscCall(PetscOptionsEnum("-dm_blocking_type", "Topological point or field node blocking", "DMSetBlockingType", DMBlockingTypes, (PetscEnum)dm->blocking_type, (PetscEnum *)&dm->blocking_type, NULL));
    912:   PetscCall(PetscOptionsEnum("-dm_is_coloring_type", "Global or local coloring of Jacobian", "DMSetISColoringType", ISColoringTypes, (PetscEnum)dm->coloringtype, (PetscEnum *)&dm->coloringtype, NULL));
    913:   PetscCall(PetscOptionsInt("-dm_bind_below", "Set the size threshold (in entries) below which the Vec is bound to the CPU", "VecBindToCPU", dm->bind_below, &dm->bind_below, &flg));
    914:   PetscCall(PetscOptionsBool("-dm_ignore_perm_output", "Ignore the local section permutation on output", "DMGetOutputDM", dm->ignorePermOutput, &dm->ignorePermOutput, NULL));
    915:   PetscTryTypeMethod(dm, setfromoptions, PetscOptionsObject);
    916:   /* process any options handlers added with PetscObjectAddOptionsHandler() */
    917:   PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)dm, PetscOptionsObject));
    918:   PetscOptionsEnd();
    919:   PetscFunctionReturn(PETSC_SUCCESS);
    920: }

    922: /*@
    923:   DMViewFromOptions - View a `DM` in a particular way based on a request in the options database

    925:   Collective

    927:   Input Parameters:
    928: + dm   - the `DM` object
    929: . obj  - optional object that provides the prefix for the options database (if `NULL` then the prefix in `obj` is used)
    930: - name - option string that is used to activate viewing

    932:   Level: intermediate

    934:   Note:
    935:   See `PetscObjectViewFromOptions()` for a list of values that can be provided in the options database to determine how the `DM` is viewed

    937: .seealso: [](ch_dmbase), `DM`, `DMView()`, `PetscObjectViewFromOptions()`, `DMCreate()`
    938: @*/
    939: PetscErrorCode DMViewFromOptions(DM dm, PeOp PetscObject obj, const char name[])
    940: {
    941:   PetscFunctionBegin;
    943:   PetscCall(PetscObjectViewFromOptions((PetscObject)dm, obj, name));
    944:   PetscFunctionReturn(PETSC_SUCCESS);
    945: }

    947: /*@
    948:   DMView - Views a `DM`. Depending on the `PetscViewer` and its `PetscViewerFormat` it may print some ASCII information about the `DM` to the screen or a file or
    949:   save the `DM` in a binary file to be loaded later or create a visualization of the `DM`

    951:   Collective

    953:   Input Parameters:
    954: + dm - the `DM` object to view
    955: - v  - the viewer

    957:   Options Database Keys:
    958: + -view_pyvista_warp <f>                 - Warps the mesh by the active scalar with factor f
    959: - -view_pyvista_clip <xl,xu,yl,yu,zl,zu> - Defines the clipping box

    961:   Level: beginner

    963:   Notes:

    965:   `PetscViewer` = `PETSCVIEWERHDF5` i.e. HDF5 format can be used with `PETSC_VIEWER_HDF5_PETSC` as the `PetscViewerFormat` to save multiple `DMPLEX`
    966:   meshes in a single HDF5 file. This in turn requires one to name the `DMPLEX` object with `PetscObjectSetName()`
    967:   before saving it with `DMView()` and before loading it with `DMLoad()` for identification of the mesh object.

    969:   `PetscViewer` = `PETSCVIEWEREXODUSII` i.e. ExodusII format assumes that element blocks (mapped to "Cell sets" labels)
    970:   consists of sequentially numbered cells.

    972:   If `dm` has been distributed, only the part of the `DM` on MPI rank 0 (including "ghost" cells and vertices) will be written.

    974:   Only TRI, TET, QUAD, and HEX cells are supported in ExodusII.

    976:   `DMPLEX` only represents geometry while most post-processing software expect that a mesh also provides information on the discretization space. This function assumes that the file represents Lagrange finite elements of order 1 or 2.
    977:   The order of the mesh shall be set using `PetscViewerExodusIISetOrder()`

    979:   Variable names can be set and queried using `PetscViewerExodusII[Set/Get][Nodal/Zonal]VariableNames[s]`.

    981: .seealso: [](ch_dmbase), `DM`, `PetscViewer`, `PetscViewerFormat`, `PetscViewerSetFormat()`, `DMDestroy()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMLoad()`, `PetscObjectSetName()`
    982: @*/
    983: PetscErrorCode DMView(DM dm, PetscViewer v)
    984: {
    985:   PetscBool         isbinary;
    986:   PetscMPIInt       size;
    987:   PetscViewerFormat format;

    989:   PetscFunctionBegin;
    991:   if (!v) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)dm), &v));
    993:   /* Ideally, we would like to have this test on.
    994:      However, it currently breaks socket viz via GLVis.
    995:      During DMView(parallel_mesh,glvis_viewer), each
    996:      process opens a sequential ASCII socket to visualize
    997:      the local mesh, and PetscObjectView(dm,local_socket)
    998:      is internally called inside VecView_GLVis, incurring
    999:      in an error here */
    1000:   /* PetscCheckSameComm(dm,1,v,2); */
    1001:   PetscCall(PetscViewerCheckWritable(v));

    1003:   PetscCall(PetscLogEventBegin(DM_View, v, 0, 0, 0));
    1004:   PetscCall(PetscViewerGetFormat(v, &format));
    1005:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size));
    1006:   if (size == 1 && format == PETSC_VIEWER_LOAD_BALANCE) PetscFunctionReturn(PETSC_SUCCESS);
    1007:   PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)dm, v));
    1008:   PetscCall(PetscObjectTypeCompare((PetscObject)v, PETSCVIEWERBINARY, &isbinary));
    1009:   if (isbinary) {
    1010:     PetscInt classid = DM_FILE_CLASSID;
    1011:     char     type[256];

    1013:     PetscCall(PetscViewerBinaryWrite(v, &classid, 1, PETSC_INT));
    1014:     PetscCall(PetscStrncpy(type, ((PetscObject)dm)->type_name, sizeof(type)));
    1015:     PetscCall(PetscViewerBinaryWrite(v, type, 256, PETSC_CHAR));
    1016:   }
    1017:   PetscTryTypeMethod(dm, view, v);
    1018:   PetscCall(PetscLogEventEnd(DM_View, v, 0, 0, 0));
    1019:   PetscFunctionReturn(PETSC_SUCCESS);
    1020: }

    1022: /*@
    1023:   DMCreateGlobalVector - Creates a global vector from a `DM` object. A global vector is a parallel vector that has no duplicate values shared between MPI ranks,
    1024:   that is it has no ghost locations.

    1026:   Collective

    1028:   Input Parameter:
    1029: . dm - the `DM` object

    1031:   Output Parameter:
    1032: . vec - the global vector

    1034:   Level: beginner

    1036: .seealso: [](ch_dmbase), `DM`, `Vec`, `DMCreateLocalVector()`, `DMGetGlobalVector()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`,
    1037:          `DMGlobalToLocalBegin()`, `DMGlobalToLocalEnd()`
    1038: @*/
    1039: PetscErrorCode DMCreateGlobalVector(DM dm, Vec *vec)
    1040: {
    1041:   PetscFunctionBegin;
    1043:   PetscAssertPointer(vec, 2);
    1044:   PetscUseTypeMethod(dm, createglobalvector, vec);
    1045:   if (PetscDefined(USE_DEBUG)) {
    1046:     DM vdm;

    1048:     PetscCall(VecGetDM(*vec, &vdm));
    1049:     PetscCheck(vdm, PETSC_COMM_SELF, PETSC_ERR_PLIB, "DM type '%s' did not attach the DM to the vector", ((PetscObject)dm)->type_name);
    1050:   }
    1051:   PetscFunctionReturn(PETSC_SUCCESS);
    1052: }

    1054: /*@
    1055:   DMCreateLocalVector - Creates a local vector from a `DM` object.

    1057:   Not Collective

    1059:   Input Parameter:
    1060: . dm - the `DM` object

    1062:   Output Parameter:
    1063: . vec - the local vector

    1065:   Level: beginner

    1067:   Note:
    1068:   A local vector usually has ghost locations that contain values that are owned by different MPI ranks. A global vector has no ghost locations.

    1070: .seealso: [](ch_dmbase), `DM`, `Vec`, `DMCreateGlobalVector()`, `DMGetLocalVector()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`
    1071:          `DMGlobalToLocalBegin()`, `DMGlobalToLocalEnd()`
    1072: @*/
    1073: PetscErrorCode DMCreateLocalVector(DM dm, Vec *vec)
    1074: {
    1075:   PetscFunctionBegin;
    1077:   PetscAssertPointer(vec, 2);
    1078:   PetscUseTypeMethod(dm, createlocalvector, vec);
    1079:   if (PetscDefined(USE_DEBUG)) {
    1080:     DM vdm;

    1082:     PetscCall(VecGetDM(*vec, &vdm));
    1083:     PetscCheck(vdm, PETSC_COMM_SELF, PETSC_ERR_LIB, "DM type '%s' did not attach the DM to the vector", ((PetscObject)dm)->type_name);
    1084:   }
    1085:   PetscFunctionReturn(PETSC_SUCCESS);
    1086: }

    1088: /*@
    1089:   DMGetLocalToGlobalMapping - Accesses the local-to-global mapping in a `DM`.

    1091:   Collective

    1093:   Input Parameter:
    1094: . dm - the `DM` that provides the mapping

    1096:   Output Parameter:
    1097: . ltog - the mapping

    1099:   Level: advanced

    1101:   Notes:
    1102:   The global to local mapping allows one to set values into the global vector or matrix using `VecSetValuesLocal()` and `MatSetValuesLocal()`

    1104:   Vectors obtained with  `DMCreateGlobalVector()` and matrices obtained with `DMCreateMatrix()` already contain the global mapping so you do
    1105:   need to use this function with those objects.

    1107:   This mapping can then be used by `VecSetLocalToGlobalMapping()` or `MatSetLocalToGlobalMapping()`.

    1109: .seealso: [](ch_dmbase), `DM`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`, `VecSetLocalToGlobalMapping()`, `MatSetLocalToGlobalMapping()`,
    1110:           `DMCreateMatrix()`
    1111: @*/
    1112: PetscErrorCode DMGetLocalToGlobalMapping(DM dm, ISLocalToGlobalMapping *ltog)
    1113: {
    1114:   PetscInt bs = -1, bsLocal[2], bsMinMax[2];

    1116:   PetscFunctionBegin;
    1118:   PetscAssertPointer(ltog, 2);
    1119:   if (!dm->ltogmap) {
    1120:     PetscSection section, sectionGlobal;

    1122:     PetscCall(DMGetLocalSection(dm, &section));
    1123:     if (section) {
    1124:       const PetscInt *cdofs;
    1125:       PetscInt       *ltog;
    1126:       PetscInt        pStart, pEnd, n, p, k, l;

    1128:       PetscCall(DMGetGlobalSection(dm, &sectionGlobal));
    1129:       PetscCall(PetscSectionGetChart(section, &pStart, &pEnd));
    1130:       PetscCall(PetscSectionGetStorageSize(section, &n));
    1131:       PetscCall(PetscMalloc1(n, &ltog)); /* We want the local+overlap size */
    1132:       for (p = pStart, l = 0; p < pEnd; ++p) {
    1133:         PetscInt bdof, cdof, dof, off, c, cind;

    1135:         /* Should probably use constrained dofs */
    1136:         PetscCall(PetscSectionGetDof(section, p, &dof));
    1137:         PetscCall(PetscSectionGetConstraintDof(section, p, &cdof));
    1138:         PetscCall(PetscSectionGetConstraintIndices(section, p, &cdofs));
    1139:         PetscCall(PetscSectionGetOffset(sectionGlobal, p, &off));
    1140:         /* If you have dofs, and constraints, and they are unequal, we set the blocksize to 1 */
    1141:         bdof = cdof && (dof - cdof) ? 1 : dof;
    1142:         if (dof) bs = bs < 0 ? bdof : PetscGCD(bs, bdof);

    1144:         for (c = 0, cind = 0; c < dof; ++c, ++l) {
    1145:           if (cind < cdof && c == cdofs[cind]) {
    1146:             ltog[l] = off < 0 ? off - c : -(off + c + 1);
    1147:             cind++;
    1148:           } else {
    1149:             ltog[l] = (off < 0 ? -(off + 1) : off) + c - cind;
    1150:           }
    1151:         }
    1152:       }
    1153:       /* Must have same blocksize on all procs (some might have no points) */
    1154:       bsLocal[0] = bs < 0 ? PETSC_INT_MAX : bs;
    1155:       bsLocal[1] = bs;
    1156:       PetscCall(PetscGlobalMinMaxInt(PetscObjectComm((PetscObject)dm), bsLocal, bsMinMax));
    1157:       if (bsMinMax[0] != bsMinMax[1]) {
    1158:         bs = 1;
    1159:       } else {
    1160:         bs = bsMinMax[0];
    1161:       }
    1162:       bs = bs < 0 ? 1 : bs;
    1163:       /* Must reduce indices by blocksize */
    1164:       if (bs > 1) {
    1165:         for (l = 0, k = 0; l < n; l += bs, ++k) {
    1166:           // Integer division of negative values truncates toward zero(!), not toward negative infinity
    1167:           ltog[k] = ltog[l] >= 0 ? ltog[l] / bs : -(-(ltog[l] + 1) / bs + 1);
    1168:         }
    1169:         n /= bs;
    1170:       }
    1171:       PetscCall(ISLocalToGlobalMappingCreate(PetscObjectComm((PetscObject)dm), bs, n, ltog, PETSC_OWN_POINTER, &dm->ltogmap));
    1172:     } else PetscUseTypeMethod(dm, getlocaltoglobalmapping);
    1173:   }
    1174:   *ltog = dm->ltogmap;
    1175:   PetscFunctionReturn(PETSC_SUCCESS);
    1176: }

    1178: /*@
    1179:   DMGetBlockSize - Gets the inherent block size associated with a `DM`

    1181:   Not Collective

    1183:   Input Parameter:
    1184: . dm - the `DM` with block structure

    1186:   Output Parameter:
    1187: . bs - the block size, 1 implies no exploitable block structure

    1189:   Level: intermediate

    1191:   Notes:
    1192:   This might be the number of degrees of freedom at each grid point for a structured grid.

    1194:   Complex `DM` that represent multiphysics or staggered grids or mixed-methods do not generally have a single inherent block size, but
    1195:   rather different locations in the vectors may have a different block size.

    1197: .seealso: [](ch_dmbase), `DM`, `ISCreateBlock()`, `VecSetBlockSize()`, `MatSetBlockSize()`, `DMGetLocalToGlobalMapping()`
    1198: @*/
    1199: PetscErrorCode DMGetBlockSize(DM dm, PetscInt *bs)
    1200: {
    1201:   PetscFunctionBegin;
    1203:   PetscAssertPointer(bs, 2);
    1204:   PetscCheck(dm->bs >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "DM does not have enough information to provide a block size yet");
    1205:   *bs = dm->bs;
    1206:   PetscFunctionReturn(PETSC_SUCCESS);
    1207: }

    1209: /*@
    1210:   DMCreateInterpolation - Gets the interpolation matrix between two `DM` objects. The resulting matrix map degrees of freedom in the vector obtained by
    1211:   `DMCreateGlobalVector()` on the coarse `DM` to similar vectors on the fine grid `DM`.

    1213:   Collective

    1215:   Input Parameters:
    1216: + dmc - the `DM` object
    1217: - dmf - the second, finer `DM` object

    1219:   Output Parameters:
    1220: + mat - the interpolation
    1221: - vec - the scaling (optional, pass `NULL` if not needed), see `DMCreateInterpolationScale()`

    1223:   Level: developer

    1225:   Notes:
    1226:   For `DMDA` objects this only works for "uniform refinement", that is the refined mesh was obtained `DMRefine()` or the coarse mesh was obtained by
    1227:   DMCoarsen(). The coordinates set into the `DMDA` are completely ignored in computing the interpolation.

    1229:   For `DMDA` objects you can use this interpolation (more precisely the interpolation from the `DMGetCoordinateDM()`) to interpolate the mesh coordinate
    1230:   vectors EXCEPT in the periodic case where it does not make sense since the coordinate vectors are not periodic.

    1232: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolationScale()`
    1233: @*/
    1234: PetscErrorCode DMCreateInterpolation(DM dmc, DM dmf, Mat *mat, Vec *vec)
    1235: {
    1236:   PetscFunctionBegin;
    1239:   PetscAssertPointer(mat, 3);
    1240:   PetscCall(PetscLogEventBegin(DM_CreateInterpolation, dmc, dmf, 0, 0));
    1241:   PetscUseTypeMethod(dmc, createinterpolation, dmf, mat, vec);
    1242:   PetscCall(PetscLogEventEnd(DM_CreateInterpolation, dmc, dmf, 0, 0));
    1243:   PetscFunctionReturn(PETSC_SUCCESS);
    1244: }

    1246: /*@
    1247:   DMCreateInterpolationScale - Forms L = 1/(R*1) where 1 is the vector of all ones, and R is
    1248:   the transpose of the interpolation between the `DM`.

    1250:   Input Parameters:
    1251: + dac - `DM` that defines a coarse mesh
    1252: . daf - `DM` that defines a fine mesh
    1253: - mat - the restriction (or interpolation operator) from fine to coarse

    1255:   Output Parameter:
    1256: . scale - the scaled vector

    1258:   Level: advanced

    1260:   Note:
    1261:   xcoarse = diag(L)*R*xfine preserves scale and is thus suitable for state (versus residual)
    1262:   restriction. In other words xcoarse is the coarse representation of xfine.

    1264:   Developer Note:
    1265:   If the fine-scale `DMDA` has the -dm_bind_below option set to true, then `DMCreateInterpolationScale()` calls `MatSetBindingPropagates()`
    1266:   on the restriction/interpolation operator to set the bindingpropagates flag to true.

    1268: .seealso: [](ch_dmbase), `DM`, `MatRestrict()`, `MatInterpolate()`, `DMCreateInterpolation()`, `DMCreateRestriction()`, `DMCreateGlobalVector()`
    1269: @*/
    1270: PetscErrorCode DMCreateInterpolationScale(DM dac, DM daf, Mat mat, Vec *scale)
    1271: {
    1272:   Vec         fine;
    1273:   PetscScalar one = 1.0;
    1274: #if defined(PETSC_HAVE_CUDA)
    1275:   PetscBool bindingpropagates, isbound;
    1276: #endif

    1278:   PetscFunctionBegin;
    1279:   PetscCall(DMCreateGlobalVector(daf, &fine));
    1280:   PetscCall(DMCreateGlobalVector(dac, scale));
    1281:   PetscCall(VecSet(fine, one));
    1282: #if defined(PETSC_HAVE_CUDA)
    1283:   /* If the 'fine' Vec is bound to the CPU, it makes sense to bind 'mat' as well.
    1284:    * Note that we only do this for the CUDA case, right now, but if we add support for MatMultTranspose() via ViennaCL,
    1285:    * we'll need to do it for that case, too.*/
    1286:   PetscCall(VecGetBindingPropagates(fine, &bindingpropagates));
    1287:   if (bindingpropagates) {
    1288:     PetscCall(MatSetBindingPropagates(mat, PETSC_TRUE));
    1289:     PetscCall(VecBoundToCPU(fine, &isbound));
    1290:     PetscCall(MatBindToCPU(mat, isbound));
    1291:   }
    1292: #endif
    1293:   PetscCall(MatRestrict(mat, fine, *scale));
    1294:   PetscCall(VecDestroy(&fine));
    1295:   PetscCall(VecReciprocal(*scale));
    1296:   PetscFunctionReturn(PETSC_SUCCESS);
    1297: }

    1299: /*@
    1300:   DMCreateRestriction - Gets restriction matrix between two `DM` objects. The resulting matrix map degrees of freedom in the vector obtained by
    1301:   `DMCreateGlobalVector()` on the fine `DM` to similar vectors on the coarse grid `DM`.

    1303:   Collective

    1305:   Input Parameters:
    1306: + dmc - the `DM` object
    1307: - dmf - the second, finer `DM` object

    1309:   Output Parameter:
    1310: . mat - the restriction

    1312:   Level: developer

    1314:   Note:
    1315:   This only works for `DMSTAG`. For many situations either the transpose of the operator obtained with `DMCreateInterpolation()` or that
    1316:   matrix multiplied by the vector obtained with `DMCreateInterpolationScale()` provides the desired object.

    1318: .seealso: [](ch_dmbase), `DM`, `DMRestrict()`, `DMInterpolate()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateInterpolation()`
    1319: @*/
    1320: PetscErrorCode DMCreateRestriction(DM dmc, DM dmf, Mat *mat)
    1321: {
    1322:   PetscFunctionBegin;
    1325:   PetscAssertPointer(mat, 3);
    1326:   PetscCall(PetscLogEventBegin(DM_CreateRestriction, dmc, dmf, 0, 0));
    1327:   PetscUseTypeMethod(dmc, createrestriction, dmf, mat);
    1328:   PetscCall(PetscLogEventEnd(DM_CreateRestriction, dmc, dmf, 0, 0));
    1329:   PetscFunctionReturn(PETSC_SUCCESS);
    1330: }

    1332: /*@
    1333:   DMCreateInjection - Gets injection matrix between two `DM` objects.

    1335:   Collective

    1337:   Input Parameters:
    1338: + dac - the `DM` object
    1339: - daf - the second, finer `DM` object

    1341:   Output Parameter:
    1342: . mat - the injection

    1344:   Level: developer

    1346:   Notes:
    1347:   This is an operator that applied to a vector obtained with `DMCreateGlobalVector()` on the
    1348:   fine grid maps the values to a vector on the vector on the coarse `DM` by simply selecting
    1349:   the values on the coarse grid points. This compares to the operator obtained by
    1350:   `DMCreateRestriction()` or the transpose of the operator obtained by
    1351:   `DMCreateInterpolation()` that uses a "local weighted average" of the values around the
    1352:   coarse grid point as the coarse grid value.

    1354:   For `DMDA` objects this only works for "uniform refinement", that is the refined mesh was obtained `DMRefine()` or the coarse mesh was obtained by
    1355:   `DMCoarsen()`. The coordinates set into the `DMDA` are completely ignored in computing the injection.

    1357: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMCreateInterpolation()`,
    1358:           `DMCreateRestriction()`, `MatRestrict()`, `MatInterpolate()`
    1359: @*/
    1360: PetscErrorCode DMCreateInjection(DM dac, DM daf, Mat *mat)
    1361: {
    1362:   PetscFunctionBegin;
    1365:   PetscAssertPointer(mat, 3);
    1366:   PetscCall(PetscLogEventBegin(DM_CreateInjection, dac, daf, 0, 0));
    1367:   PetscUseTypeMethod(dac, createinjection, daf, mat);
    1368:   PetscCall(PetscLogEventEnd(DM_CreateInjection, dac, daf, 0, 0));
    1369:   PetscFunctionReturn(PETSC_SUCCESS);
    1370: }

    1372: /*@
    1373:   DMCreateMassMatrix - Gets the mass matrix between two `DM` objects, M_ij = \int \phi_i \psi_j where the \phi are Galerkin basis functions for a
    1374:   a Galerkin finite element model on the `DM`

    1376:   Collective

    1378:   Input Parameters:
    1379: + dmc - the target `DM` object
    1380: - dmf - the source `DM` object, can be `NULL`

    1382:   Output Parameter:
    1383: . mat - the mass matrix

    1385:   Level: developer

    1387:   Notes:
    1388:   For `DMPLEX` the finite element model for the `DM` must have been already provided.

    1390:   if `dmc` is `dmf` or `NULL`, then x^t M x is an approximation to the L2 norm of the vector x which is obtained by `DMCreateGlobalVector()`

    1392: .seealso: [](ch_dmbase), `DM`, `DMCreateMassMatrixLumped()`, `DMCreateMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolation()`, `DMCreateInjection()`
    1393: @*/
    1394: PetscErrorCode DMCreateMassMatrix(DM dmc, DM dmf, Mat *mat)
    1395: {
    1396:   PetscFunctionBegin;
    1398:   if (!dmf) dmf = dmc;
    1400:   PetscAssertPointer(mat, 3);
    1401:   PetscCall(PetscLogEventBegin(DM_CreateMassMatrix, dmc, dmf, 0, 0));
    1402:   PetscUseTypeMethod(dmc, createmassmatrix, dmf, mat);
    1403:   PetscCall(PetscLogEventEnd(DM_CreateMassMatrix, dmc, dmf, 0, 0));
    1404:   PetscFunctionReturn(PETSC_SUCCESS);
    1405: }

    1407: /*@
    1408:   DMCreateMassMatrixLumped - Gets the lumped mass matrix for a given `DM`

    1410:   Collective

    1412:   Input Parameter:
    1413: . dm - the `DM` object

    1415:   Output Parameters:
    1416: + llm - the local lumped mass matrix, which is a diagonal matrix, represented as a vector
    1417: - lm  - the global lumped mass matrix, which is a diagonal matrix, represented as a vector

    1419:   Level: developer

    1421:   Note:
    1422:   See `DMCreateMassMatrix()` for how to create the non-lumped version of the mass matrix.

    1424: .seealso: [](ch_dmbase), `DM`, `DMCreateMassMatrix()`, `DMCreateMatrix()`, `DMRefine()`, `DMCoarsen()`, `DMCreateRestriction()`, `DMCreateInterpolation()`, `DMCreateInjection()`
    1425: @*/
    1426: PetscErrorCode DMCreateMassMatrixLumped(DM dm, Vec *llm, Vec *lm)
    1427: {
    1428:   PetscFunctionBegin;
    1430:   if (llm) PetscAssertPointer(llm, 2);
    1431:   if (lm) PetscAssertPointer(lm, 3);
    1432:   if (llm || lm) PetscUseTypeMethod(dm, createmassmatrixlumped, llm, lm);
    1433:   PetscFunctionReturn(PETSC_SUCCESS);
    1434: }

    1436: /*@
    1437:   DMCreateColoring - Gets coloring of a graph associated with the `DM`. Often the graph represents the operator matrix associated with the discretization
    1438:   of a PDE on the `DM`.

    1440:   Collective

    1442:   Input Parameters:
    1443: + dm    - the `DM` object
    1444: - ctype - `IS_COLORING_LOCAL` or `IS_COLORING_GLOBAL`

    1446:   Output Parameter:
    1447: . coloring - the coloring

    1449:   Level: developer

    1451:   Notes:
    1452:   Coloring of matrices can also be computed directly from the sparse matrix nonzero structure via the `MatColoring` object or from the mesh from which the
    1453:   matrix comes from (what this function provides). In general using the mesh produces a more optimal coloring (fewer colors).

    1455:   This produces a coloring with the distance of 2, see `MatSetColoringDistance()` which can be used for efficiently computing Jacobians with `MatFDColoringCreate()`
    1456:   For `DMDA` in three dimensions with periodic boundary conditions the number of grid points in each dimension must be divisible by 2*stencil_width + 1,
    1457:   otherwise an error will be generated.

    1459: .seealso: [](ch_dmbase), `DM`, `ISColoring`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatType()`, `MatColoring`, `MatFDColoringCreate()`
    1460: @*/
    1461: PetscErrorCode DMCreateColoring(DM dm, ISColoringType ctype, ISColoring *coloring)
    1462: {
    1463:   PetscFunctionBegin;
    1465:   PetscAssertPointer(coloring, 3);
    1466:   PetscUseTypeMethod(dm, getcoloring, ctype, coloring);
    1467:   PetscFunctionReturn(PETSC_SUCCESS);
    1468: }

    1470: /*@
    1471:   DMCreateMatrix - Gets an empty matrix for a `DM` that is most commonly used to store the Jacobian of a discrete PDE operator.

    1473:   Collective

    1475:   Input Parameter:
    1476: . dm - the `DM` object

    1478:   Output Parameter:
    1479: . mat - the empty Jacobian

    1481:   Options Database Key:
    1482: . -dm_preallocate_only - Only preallocate the matrix for `DMCreateMatrix()` and `DMCreateMassMatrix()`, but do not fill it with zeros

    1484:   Level: beginner

    1486:   Notes:
    1487:   This properly preallocates the number of nonzeros in the sparse matrix so you
    1488:   do not need to do it yourself.

    1490:   By default it also sets the nonzero structure and puts in the zero entries. To prevent setting
    1491:   the nonzero pattern call `DMSetMatrixPreallocateOnly()`

    1493:   For `DMDA`, when you call `MatView()` on this matrix it is displayed using the global natural ordering, NOT in the ordering used
    1494:   internally by PETSc.

    1496:   For `DMDA`, in general it is easiest to use `MatSetValuesStencil()` or `MatSetValuesLocal()` to put values into the matrix because
    1497:   `MatSetValues()` requires the indices for the global numbering for the `DMDA` which is complic`ated to compute

    1499: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMSetMatType()`, `DMCreateMassMatrix()`
    1500: @*/
    1501: PetscErrorCode DMCreateMatrix(DM dm, Mat *mat)
    1502: {
    1503:   PetscFunctionBegin;
    1505:   PetscAssertPointer(mat, 2);
    1506:   PetscCall(MatInitializePackage());
    1507:   PetscCall(PetscLogEventBegin(DM_CreateMatrix, 0, 0, 0, 0));
    1508:   PetscUseTypeMethod(dm, creatematrix, mat);
    1509:   if (PetscDefined(USE_DEBUG)) {
    1510:     DM mdm;

    1512:     PetscCall(MatGetDM(*mat, &mdm));
    1513:     PetscCheck(mdm, PETSC_COMM_SELF, PETSC_ERR_PLIB, "DM type '%s' did not attach the DM to the matrix", ((PetscObject)dm)->type_name);
    1514:   }
    1515:   /* Handle nullspace and near nullspace */
    1516:   if (dm->Nf) {
    1517:     MatNullSpace nullSpace;
    1518:     PetscInt     Nf, f;

    1520:     PetscCall(DMGetNumFields(dm, &Nf));
    1521:     for (f = 0; f < Nf; ++f) {
    1522:       if (dm->nullspaceConstructors[f]) {
    1523:         PetscCall((*dm->nullspaceConstructors[f])(dm, f, f, &nullSpace));
    1524:         PetscCall(MatSetNullSpace(*mat, nullSpace));
    1525:         PetscCall(MatNullSpaceDestroy(&nullSpace));
    1526:         break;
    1527:       }
    1528:     }
    1529:     for (f = 0; f < Nf; ++f) {
    1530:       if (dm->nearnullspaceConstructors[f]) {
    1531:         PetscCall((*dm->nearnullspaceConstructors[f])(dm, f, f, &nullSpace));
    1532:         PetscCall(MatSetNearNullSpace(*mat, nullSpace));
    1533:         PetscCall(MatNullSpaceDestroy(&nullSpace));
    1534:       }
    1535:     }
    1536:   }
    1537:   PetscCall(PetscLogEventEnd(DM_CreateMatrix, 0, 0, 0, 0));
    1538:   PetscFunctionReturn(PETSC_SUCCESS);
    1539: }

    1541: /*@
    1542:   DMSetMatrixPreallocateSkip - When `DMCreateMatrix()` is called the matrix sizes and
    1543:   `ISLocalToGlobalMapping` will be properly set, but the data structures to store values in the
    1544:   matrices will not be preallocated.

    1546:   Logically Collective

    1548:   Input Parameters:
    1549: + dm   - the `DM`
    1550: - skip - `PETSC_TRUE` to skip preallocation

    1552:   Level: developer

    1554:   Note:
    1555:   This is most useful to reduce initialization costs when `MatSetPreallocationCOO()` and
    1556:   `MatSetValuesCOO()` will be used.

    1558: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `DMSetMatrixStructureOnly()`, `DMSetMatrixPreallocateOnly()`
    1559: @*/
    1560: PetscErrorCode DMSetMatrixPreallocateSkip(DM dm, PetscBool skip)
    1561: {
    1562:   PetscFunctionBegin;
    1564:   dm->prealloc_skip = skip;
    1565:   PetscFunctionReturn(PETSC_SUCCESS);
    1566: }

    1568: /*@
    1569:   DMSetMatrixPreallocateOnly - When `DMCreateMatrix()` is called the matrix will be properly
    1570:   preallocated but the nonzero structure and zero values will not be set.

    1572:   Logically Collective

    1574:   Input Parameters:
    1575: + dm   - the `DM`
    1576: - only - `PETSC_TRUE` if only want preallocation

    1578:   Options Database Key:
    1579: . -dm_preallocate_only - Only preallocate the matrix for `DMCreateMatrix()`, `DMCreateMassMatrix()`, but do not fill it with zeros

    1581:   Level: developer

    1583: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMSetMatrixStructureOnly()`, `DMSetMatrixPreallocateSkip()`
    1584: @*/
    1585: PetscErrorCode DMSetMatrixPreallocateOnly(DM dm, PetscBool only)
    1586: {
    1587:   PetscFunctionBegin;
    1589:   dm->prealloc_only = only;
    1590:   PetscFunctionReturn(PETSC_SUCCESS);
    1591: }

    1593: /*@
    1594:   DMSetMatrixStructureOnly - When `DMCreateMatrix()` is called, the matrix nonzero structure will be created
    1595:   but the array for numerical values will not be allocated.

    1597:   Logically Collective

    1599:   Input Parameters:
    1600: + dm   - the `DM`
    1601: - only - `PETSC_TRUE` if you only want matrix nonzero structure

    1603:   Level: developer

    1605: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `DMSetMatrixPreallocateOnly()`, `DMSetMatrixPreallocateSkip()`
    1606: @*/
    1607: PetscErrorCode DMSetMatrixStructureOnly(DM dm, PetscBool only)
    1608: {
    1609:   PetscFunctionBegin;
    1611:   dm->structure_only = only;
    1612:   PetscFunctionReturn(PETSC_SUCCESS);
    1613: }

    1615: /*@
    1616:   DMSetBlockingType - set the blocking granularity to be used for variable block size `DMCreateMatrix()` is called

    1618:   Logically Collective

    1620:   Input Parameters:
    1621: + dm    - the `DM`
    1622: - btype - block by topological point or field node

    1624:   Options Database Key:
    1625: . -dm_blocking_type [topological_point, field_node] - use topological point blocking or field node blocking

    1627:   Level: advanced

    1629: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `MatSetVariableBlockSizes()`
    1630: @*/
    1631: PetscErrorCode DMSetBlockingType(DM dm, DMBlockingType btype)
    1632: {
    1633:   PetscFunctionBegin;
    1635:   dm->blocking_type = btype;
    1636:   PetscFunctionReturn(PETSC_SUCCESS);
    1637: }

    1639: /*@
    1640:   DMGetBlockingType - get the blocking granularity to be used for variable block size `DMCreateMatrix()` is called

    1642:   Not Collective

    1644:   Input Parameter:
    1645: . dm - the `DM`

    1647:   Output Parameter:
    1648: . btype - block by topological point or field node

    1650:   Level: advanced

    1652: .seealso: [](ch_dmbase), `DM`, `DMCreateMatrix()`, `MatSetVariableBlockSizes()`
    1653: @*/
    1654: PetscErrorCode DMGetBlockingType(DM dm, DMBlockingType *btype)
    1655: {
    1656:   PetscFunctionBegin;
    1658:   PetscAssertPointer(btype, 2);
    1659:   *btype = dm->blocking_type;
    1660:   PetscFunctionReturn(PETSC_SUCCESS);
    1661: }

    1663: /*@C
    1664:   DMGetWorkArray - Gets a work array guaranteed to be at least the input size, restore with `DMRestoreWorkArray()`

    1666:   Not Collective

    1668:   Input Parameters:
    1669: + dm    - the `DM` object
    1670: . count - The minimum size
    1671: - dtype - MPI data type, often `MPIU_REAL`, `MPIU_SCALAR`, or `MPIU_INT`)

    1673:   Output Parameter:
    1674: . mem - the work array

    1676:   Level: developer

    1678:   Notes:
    1679:   A `DM` may stash the array between instantiations so using this routine may be more efficient than calling `PetscMalloc()`

    1681:   The array may contain nonzero values

    1683: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMCreate()`, `DMRestoreWorkArray()`, `PetscMalloc()`
    1684: @*/
    1685: PetscErrorCode DMGetWorkArray(DM dm, PetscInt count, MPI_Datatype dtype, void *mem)
    1686: {
    1687:   DMWorkLink  link;
    1688:   PetscMPIInt dsize;

    1690:   PetscFunctionBegin;
    1692:   PetscAssertPointer(mem, 4);
    1693:   if (!count) {
    1694:     *(void **)mem = NULL;
    1695:     PetscFunctionReturn(PETSC_SUCCESS);
    1696:   }
    1697:   if (dm->workin) {
    1698:     link       = dm->workin;
    1699:     dm->workin = dm->workin->next;
    1700:   } else {
    1701:     PetscCall(PetscNew(&link));
    1702:   }
    1703:   /* Avoid MPI_Type_size for most used datatypes
    1704:      Get size directly */
    1705:   if (dtype == MPIU_INT) dsize = sizeof(PetscInt);
    1706:   else if (dtype == MPIU_REAL) dsize = sizeof(PetscReal);
    1707: #if defined(PETSC_USE_64BIT_INDICES)
    1708:   else if (dtype == MPI_INT) dsize = sizeof(int);
    1709: #endif
    1710: #if defined(PETSC_USE_COMPLEX)
    1711:   else if (dtype == MPIU_SCALAR) dsize = sizeof(PetscScalar);
    1712: #endif
    1713:   else PetscCallMPI(MPI_Type_size(dtype, &dsize));

    1715:   if (((size_t)dsize * count) > link->bytes) {
    1716:     PetscCall(PetscFree(link->mem));
    1717:     PetscCall(PetscMalloc(dsize * count, &link->mem));
    1718:     link->bytes = dsize * count;
    1719:   }
    1720:   link->next    = dm->workout;
    1721:   dm->workout   = link;
    1722:   *(void **)mem = link->mem;
    1723:   PetscFunctionReturn(PETSC_SUCCESS);
    1724: }

    1726: /*@C
    1727:   DMRestoreWorkArray - Restores a work array obtained with `DMCreateWorkArray()`

    1729:   Not Collective

    1731:   Input Parameters:
    1732: + dm    - the `DM` object
    1733: . count - The minimum size
    1734: - dtype - MPI data type, often `MPIU_REAL`, `MPIU_SCALAR`, `MPIU_INT`

    1736:   Output Parameter:
    1737: . mem - the work array

    1739:   Level: developer

    1741:   Developer Note:
    1742:   count and dtype are ignored, they are only needed for `DMGetWorkArray()`

    1744: .seealso: [](ch_dmbase), `DM`, `DMDestroy()`, `DMCreate()`, `DMGetWorkArray()`
    1745: @*/
    1746: PetscErrorCode DMRestoreWorkArray(DM dm, PetscInt count, MPI_Datatype dtype, void *mem)
    1747: {
    1748:   DMWorkLink *p, link;

    1750:   PetscFunctionBegin;
    1751:   PetscAssertPointer(mem, 4);
    1752:   (void)count;
    1753:   (void)dtype;
    1754:   if (!*(void **)mem) PetscFunctionReturn(PETSC_SUCCESS);
    1755:   for (p = &dm->workout; (link = *p); p = &link->next) {
    1756:     if (link->mem == *(void **)mem) {
    1757:       *p            = link->next;
    1758:       link->next    = dm->workin;
    1759:       dm->workin    = link;
    1760:       *(void **)mem = NULL;
    1761:       PetscFunctionReturn(PETSC_SUCCESS);
    1762:     }
    1763:   }
    1764:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Array was not checked out");
    1765: }

    1767: /*@C
    1768:   DMSetNullSpaceConstructor - Provide a callback function which constructs the nullspace for a given field, defined with `DMAddField()`, when function spaces
    1769:   are joined or split, such as in `DMCreateSubDM()`

    1771:   Logically Collective; No Fortran Support

    1773:   Input Parameters:
    1774: + dm     - The `DM`
    1775: . field  - The field number for the nullspace
    1776: - nullsp - A callback to create the nullspace

    1778:   Calling sequence of `nullsp`:
    1779: + dm        - The present `DM`
    1780: . origField - The field number given above, in the original `DM`
    1781: . field     - The field number in dm
    1782: - nullSpace - The nullspace for the given field

    1784:   Level: intermediate

    1786: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetNullSpaceConstructor()`, `DMSetNearNullSpaceConstructor()`, `DMGetNearNullSpaceConstructor()`, `DMCreateSubDM()`, `DMCreateSuperDM()`
    1787: @*/
    1788: PetscErrorCode DMSetNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (*nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1789: {
    1790:   PetscFunctionBegin;
    1792:   PetscCheck(field < 10, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= 10 fields", field);
    1793:   dm->nullspaceConstructors[field] = nullsp;
    1794:   PetscFunctionReturn(PETSC_SUCCESS);
    1795: }

    1797: /*@C
    1798:   DMGetNullSpaceConstructor - Return the callback function which constructs the nullspace for a given field, defined with `DMAddField()`

    1800:   Not Collective; No Fortran Support

    1802:   Input Parameters:
    1803: + dm    - The `DM`
    1804: - field - The field number for the nullspace

    1806:   Output Parameter:
    1807: . nullsp - A callback to create the nullspace

    1809:   Calling sequence of `nullsp`:
    1810: + dm        - The present DM
    1811: . origField - The field number given above, in the original DM
    1812: . field     - The field number in dm
    1813: - nullSpace - The nullspace for the given field

    1815:   Level: intermediate

    1817: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`, `DMSetNullSpaceConstructor()`, `DMSetNearNullSpaceConstructor()`, `DMGetNearNullSpaceConstructor()`, `DMCreateSubDM()`, `DMCreateSuperDM()`
    1818: @*/
    1819: PetscErrorCode DMGetNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (**nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1820: {
    1821:   PetscFunctionBegin;
    1823:   PetscAssertPointer(nullsp, 3);
    1824:   PetscCheck(field < 10, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= 10 fields", field);
    1825:   *nullsp = dm->nullspaceConstructors[field];
    1826:   PetscFunctionReturn(PETSC_SUCCESS);
    1827: }

    1829: /*@C
    1830:   DMSetNearNullSpaceConstructor - Provide a callback function which constructs the near-nullspace for a given field, defined with `DMAddField()`

    1832:   Logically Collective; No Fortran Support

    1834:   Input Parameters:
    1835: + dm     - The `DM`
    1836: . field  - The field number for the nullspace
    1837: - nullsp - A callback to create the near-nullspace

    1839:   Calling sequence of `nullsp`:
    1840: + dm        - The present `DM`
    1841: . origField - The field number given above, in the original `DM`
    1842: . field     - The field number in dm
    1843: - nullSpace - The nullspace for the given field

    1845:   Level: intermediate

    1847: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetNearNullSpaceConstructor()`, `DMSetNullSpaceConstructor()`, `DMGetNullSpaceConstructor()`, `DMCreateSubDM()`, `DMCreateSuperDM()`,
    1848:           `MatNullSpace`
    1849: @*/
    1850: PetscErrorCode DMSetNearNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (*nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1851: {
    1852:   PetscFunctionBegin;
    1854:   PetscCheck(field < 10, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= 10 fields", field);
    1855:   dm->nearnullspaceConstructors[field] = nullsp;
    1856:   PetscFunctionReturn(PETSC_SUCCESS);
    1857: }

    1859: /*@C
    1860:   DMGetNearNullSpaceConstructor - Return the callback function which constructs the near-nullspace for a given field, defined with `DMAddField()`

    1862:   Not Collective; No Fortran Support

    1864:   Input Parameters:
    1865: + dm    - The `DM`
    1866: - field - The field number for the nullspace

    1868:   Output Parameter:
    1869: . nullsp - A callback to create the near-nullspace

    1871:   Calling sequence of `nullsp`:
    1872: + dm        - The present `DM`
    1873: . origField - The field number given above, in the original `DM`
    1874: . field     - The field number in dm
    1875: - nullSpace - The nullspace for the given field

    1877:   Level: intermediate

    1879: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`, `DMSetNearNullSpaceConstructor()`, `DMSetNullSpaceConstructor()`, `DMGetNullSpaceConstructor()`, `DMCreateSubDM()`,
    1880:           `MatNullSpace`, `DMCreateSuperDM()`
    1881: @*/
    1882: PetscErrorCode DMGetNearNullSpaceConstructor(DM dm, PetscInt field, PetscErrorCode (**nullsp)(DM dm, PetscInt origField, PetscInt field, MatNullSpace *nullSpace))
    1883: {
    1884:   PetscFunctionBegin;
    1886:   PetscAssertPointer(nullsp, 3);
    1887:   PetscCheck(field < 10, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cannot handle %" PetscInt_FMT " >= 10 fields", field);
    1888:   *nullsp = dm->nearnullspaceConstructors[field];
    1889:   PetscFunctionReturn(PETSC_SUCCESS);
    1890: }

    1892: /*@C
    1893:   DMCreateFieldIS - Creates a set of `IS` objects with the global indices of dofs for each field defined with `DMAddField()`

    1895:   Not Collective; No Fortran Support

    1897:   Input Parameter:
    1898: . dm - the `DM` object

    1900:   Output Parameters:
    1901: + numFields  - The number of fields (or `NULL` if not requested)
    1902: . fieldNames - The name of each field (or `NULL` if not requested)
    1903: - fields     - The global indices for each field (or `NULL` if not requested)

    1905:   Level: intermediate

    1907:   Note:
    1908:   The user is responsible for freeing all requested arrays. In particular, every entry of `fieldNames` should be freed with
    1909:   `PetscFree()`, every entry of `fields` should be destroyed with `ISDestroy()`, and both arrays should be freed with
    1910:   `PetscFree()`.

    1912:   Developer Note:
    1913:   It is not clear why both this function and `DMCreateFieldDecomposition()` exist. Having two seems redundant and confusing. This function should
    1914:   likely be removed.

    1916: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`,
    1917:           `DMCreateFieldDecomposition()`
    1918: @*/
    1919: PetscErrorCode DMCreateFieldIS(DM dm, PetscInt *numFields, char ***fieldNames, IS *fields[])
    1920: {
    1921:   PetscSection section, sectionGlobal;

    1923:   PetscFunctionBegin;
    1925:   if (numFields) {
    1926:     PetscAssertPointer(numFields, 2);
    1927:     *numFields = 0;
    1928:   }
    1929:   if (fieldNames) {
    1930:     PetscAssertPointer(fieldNames, 3);
    1931:     *fieldNames = NULL;
    1932:   }
    1933:   if (fields) {
    1934:     PetscAssertPointer(fields, 4);
    1935:     *fields = NULL;
    1936:   }
    1937:   PetscCall(DMGetLocalSection(dm, &section));
    1938:   if (section) {
    1939:     PetscInt *fieldSizes, *fieldNc, **fieldIndices;
    1940:     PetscInt  nF, f, pStart, pEnd, p;

    1942:     PetscCall(DMGetGlobalSection(dm, &sectionGlobal));
    1943:     PetscCall(PetscSectionGetNumFields(section, &nF));
    1944:     PetscCall(PetscMalloc3(nF, &fieldSizes, nF, &fieldNc, nF, &fieldIndices));
    1945:     PetscCall(PetscSectionGetChart(sectionGlobal, &pStart, &pEnd));
    1946:     for (f = 0; f < nF; ++f) {
    1947:       fieldSizes[f] = 0;
    1948:       PetscCall(PetscSectionGetFieldComponents(section, f, &fieldNc[f]));
    1949:     }
    1950:     for (p = pStart; p < pEnd; ++p) {
    1951:       PetscInt gdof;

    1953:       PetscCall(PetscSectionGetDof(sectionGlobal, p, &gdof));
    1954:       if (gdof > 0) {
    1955:         for (f = 0; f < nF; ++f) {
    1956:           PetscInt fdof, fcdof, fpdof;

    1958:           PetscCall(PetscSectionGetFieldDof(section, p, f, &fdof));
    1959:           PetscCall(PetscSectionGetFieldConstraintDof(section, p, f, &fcdof));
    1960:           fpdof = fdof - fcdof;
    1961:           if (fpdof && fpdof != fieldNc[f]) {
    1962:             /* Layout does not admit a pointwise block size */
    1963:             fieldNc[f] = 1;
    1964:           }
    1965:           fieldSizes[f] += fpdof;
    1966:         }
    1967:       }
    1968:     }
    1969:     for (f = 0; f < nF; ++f) {
    1970:       PetscCall(PetscMalloc1(fieldSizes[f], &fieldIndices[f]));
    1971:       fieldSizes[f] = 0;
    1972:     }
    1973:     for (p = pStart; p < pEnd; ++p) {
    1974:       PetscInt gdof, goff;

    1976:       PetscCall(PetscSectionGetDof(sectionGlobal, p, &gdof));
    1977:       if (gdof > 0) {
    1978:         PetscCall(PetscSectionGetOffset(sectionGlobal, p, &goff));
    1979:         for (f = 0; f < nF; ++f) {
    1980:           PetscInt fdof, fcdof, fc;

    1982:           PetscCall(PetscSectionGetFieldDof(section, p, f, &fdof));
    1983:           PetscCall(PetscSectionGetFieldConstraintDof(section, p, f, &fcdof));
    1984:           for (fc = 0; fc < fdof - fcdof; ++fc, ++fieldSizes[f]) fieldIndices[f][fieldSizes[f]] = goff++;
    1985:         }
    1986:       }
    1987:     }
    1988:     if (numFields) *numFields = nF;
    1989:     if (fieldNames) {
    1990:       PetscCall(PetscMalloc1(nF, fieldNames));
    1991:       for (f = 0; f < nF; ++f) {
    1992:         const char *fieldName;

    1994:         PetscCall(PetscSectionGetFieldName(section, f, &fieldName));
    1995:         PetscCall(PetscStrallocpy(fieldName, &(*fieldNames)[f]));
    1996:       }
    1997:     }
    1998:     if (fields) {
    1999:       PetscCall(PetscMalloc1(nF, fields));
    2000:       for (f = 0; f < nF; ++f) {
    2001:         PetscInt bs, in[2], out[2];

    2003:         PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)dm), fieldSizes[f], fieldIndices[f], PETSC_OWN_POINTER, &(*fields)[f]));
    2004:         in[0] = -fieldNc[f];
    2005:         in[1] = fieldNc[f];
    2006:         PetscCallMPI(MPIU_Allreduce(in, out, 2, MPIU_INT, MPI_MAX, PetscObjectComm((PetscObject)dm)));
    2007:         bs = (-out[0] == out[1]) ? out[1] : 1;
    2008:         PetscCall(ISSetBlockSize((*fields)[f], bs));
    2009:       }
    2010:     }
    2011:     PetscCall(PetscFree3(fieldSizes, fieldNc, fieldIndices));
    2012:   } else PetscTryTypeMethod(dm, createfieldis, numFields, fieldNames, fields);
    2013:   PetscFunctionReturn(PETSC_SUCCESS);
    2014: }

    2016: /*@C
    2017:   DMCreateFieldDecomposition - Returns a list of `IS` objects defining a decomposition of a problem into subproblems
    2018:   corresponding to different fields.

    2020:   Not Collective; No Fortran Support

    2022:   Input Parameter:
    2023: . dm - the `DM` object

    2025:   Output Parameters:
    2026: + len      - The number of fields (or `NULL` if not requested)
    2027: . namelist - The name for each field (or `NULL` if not requested)
    2028: . islist   - The global indices for each field (or `NULL` if not requested)
    2029: - dmlist   - The `DM`s for each field subproblem (or `NULL`, if not requested; if `NULL` is returned, no `DM`s are defined)

    2031:   Level: intermediate

    2033:   Notes:
    2034:   Each `IS` contains the global indices of the dofs of the corresponding field, defined by
    2035:   `DMAddField()`. The optional list of `DM`s define the `DM` for each subproblem.

    2037:   The same as `DMCreateFieldIS()` but also returns a `DM` for each field.

    2039:   The user is responsible for freeing all requested arrays. In particular, every entry of `namelist` should be freed with
    2040:   `PetscFree()`, every entry of `islist` should be destroyed with `ISDestroy()`, every entry of `dmlist` should be destroyed with `DMDestroy()`,
    2041:   and all of the arrays should be freed with `PetscFree()`.

    2043:   Developer Notes:
    2044:   It is not clear why this function and `DMCreateFieldIS()` exist. Having two seems redundant and confusing.

    2046:   Unlike  `DMRefine()`, `DMCoarsen()`, and `DMCreateDomainDecomposition()` this provides no mechanism to provide hooks that are called after the
    2047:   decomposition is computed.

    2049: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMCreateFieldIS()`, `DMCreateSubDM()`, `DMCreateDomainDecomposition()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`
    2050: @*/
    2051: PetscErrorCode DMCreateFieldDecomposition(DM dm, PetscInt *len, char ***namelist, IS *islist[], DM *dmlist[])
    2052: {
    2053:   PetscFunctionBegin;
    2055:   if (len) {
    2056:     PetscAssertPointer(len, 2);
    2057:     *len = 0;
    2058:   }
    2059:   if (namelist) {
    2060:     PetscAssertPointer(namelist, 3);
    2061:     *namelist = NULL;
    2062:   }
    2063:   if (islist) {
    2064:     PetscAssertPointer(islist, 4);
    2065:     *islist = NULL;
    2066:   }
    2067:   if (dmlist) {
    2068:     PetscAssertPointer(dmlist, 5);
    2069:     *dmlist = NULL;
    2070:   }
    2071:   /*
    2072:    Is it a good idea to apply the following check across all impls?
    2073:    Perhaps some impls can have a well-defined decomposition before DMSetUp?
    2074:    This, however, follows the general principle that accessors are not well-behaved until the object is set up.
    2075:    */
    2076:   PetscCheck(dm->setupcalled, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Decomposition defined only after DMSetUp");
    2077:   if (!dm->ops->createfielddecomposition) {
    2078:     PetscSection section;
    2079:     PetscInt     numFields, f;

    2081:     PetscCall(DMGetLocalSection(dm, &section));
    2082:     if (section) PetscCall(PetscSectionGetNumFields(section, &numFields));
    2083:     if (section && numFields && dm->ops->createsubdm) {
    2084:       if (len) *len = numFields;
    2085:       if (namelist) PetscCall(PetscMalloc1(numFields, namelist));
    2086:       if (islist) PetscCall(PetscMalloc1(numFields, islist));
    2087:       if (dmlist) PetscCall(PetscMalloc1(numFields, dmlist));
    2088:       for (f = 0; f < numFields; ++f) {
    2089:         const char *fieldName;

    2091:         PetscCall(DMCreateSubDM(dm, 1, &f, islist ? &(*islist)[f] : NULL, dmlist ? &(*dmlist)[f] : NULL));
    2092:         if (namelist) {
    2093:           PetscCall(PetscSectionGetFieldName(section, f, &fieldName));
    2094:           PetscCall(PetscStrallocpy(fieldName, &(*namelist)[f]));
    2095:         }
    2096:       }
    2097:     } else {
    2098:       PetscCall(DMCreateFieldIS(dm, len, namelist, islist));
    2099:       /* By default there are no DMs associated with subproblems. */
    2100:       if (dmlist) *dmlist = NULL;
    2101:     }
    2102:   } else PetscUseTypeMethod(dm, createfielddecomposition, len, namelist, islist, dmlist);
    2103:   PetscFunctionReturn(PETSC_SUCCESS);
    2104: }

    2106: /*@
    2107:   DMCreateSubDM - Returns an `IS` and `DM` encapsulating a subproblem defined by the fields passed in.
    2108:   The fields are defined by `DMCreateFieldIS()`.

    2110:   Not collective

    2112:   Input Parameters:
    2113: + dm        - The `DM` object
    2114: . numFields - The number of fields to select
    2115: - fields    - The field numbers of the selected fields

    2117:   Output Parameters:
    2118: + is    - The global indices for all the degrees of freedom in the new sub `DM`, use `NULL` if not needed
    2119: - subdm - The `DM` for the subproblem, use `NULL` if not needed

    2121:   Level: intermediate

    2123:   Note:
    2124:   You need to call `DMPlexSetMigrationSF()` on the original `DM` if you want the Global-To-Natural map to be automatically constructed

    2126: .seealso: [](ch_dmbase), `DM`, `DMCreateFieldIS()`, `DMCreateFieldDecomposition()`, `DMAddField()`, `DMCreateSuperDM()`, `IS`, `DMPlexSetMigrationSF()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`
    2127: @*/
    2128: PetscErrorCode DMCreateSubDM(DM dm, PetscInt numFields, const PetscInt fields[], IS *is, DM *subdm)
    2129: {
    2130:   PetscFunctionBegin;
    2132:   PetscAssertPointer(fields, 3);
    2133:   if (is) PetscAssertPointer(is, 4);
    2134:   if (subdm) PetscAssertPointer(subdm, 5);
    2135:   PetscUseTypeMethod(dm, createsubdm, numFields, fields, is, subdm);
    2136:   PetscFunctionReturn(PETSC_SUCCESS);
    2137: }

    2139: /*@C
    2140:   DMCreateSuperDM - Returns an arrays of `IS` and a single `DM` encapsulating a superproblem defined by multiple `DM`s passed in.

    2142:   Not collective

    2144:   Input Parameters:
    2145: + dms - The `DM` objects
    2146: - n   - The number of `DM`s

    2148:   Output Parameters:
    2149: + is      - The global indices for each of subproblem within the super `DM`, or `NULL`, its length is `n`
    2150: - superdm - The `DM` for the superproblem

    2152:   Level: intermediate

    2154:   Note:
    2155:   You need to call `DMPlexSetMigrationSF()` on the original `DM` if you want the Global-To-Natural map to be automatically constructed

    2157: .seealso: [](ch_dmbase), `DM`, `DMCreateSubDM()`, `DMPlexSetMigrationSF()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMCreateFieldIS()`, `DMCreateDomainDecomposition()`
    2158: @*/
    2159: PetscErrorCode DMCreateSuperDM(DM dms[], PetscInt n, IS *is[], DM *superdm)
    2160: {
    2161:   PetscInt i;

    2163:   PetscFunctionBegin;
    2164:   PetscAssertPointer(dms, 1);
    2166:   if (is) PetscAssertPointer(is, 3);
    2167:   PetscAssertPointer(superdm, 4);
    2168:   PetscCheck(n >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of DMs must be nonnegative: %" PetscInt_FMT, n);
    2169:   if (n) {
    2170:     DM dm = dms[0];
    2171:     PetscCheck(dm->ops->createsuperdm, PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "No method createsuperdm for DM of type %s", ((PetscObject)dm)->type_name);
    2172:     PetscCall((*dm->ops->createsuperdm)(dms, n, is, superdm));
    2173:   }
    2174:   PetscFunctionReturn(PETSC_SUCCESS);
    2175: }

    2177: /*@C
    2178:   DMCreateDomainDecomposition - Returns lists of `IS` objects defining a decomposition of a
    2179:   problem into subproblems corresponding to restrictions to pairs of nested subdomains.

    2181:   Not Collective

    2183:   Input Parameter:
    2184: . dm - the `DM` object

    2186:   Output Parameters:
    2187: + n           - The number of subproblems in the domain decomposition (or `NULL` if not requested), also the length of the four arrays below
    2188: . namelist    - The name for each subdomain (or `NULL` if not requested)
    2189: . innerislist - The global indices for each inner subdomain (or `NULL`, if not requested)
    2190: . outerislist - The global indices for each outer subdomain (or `NULL`, if not requested)
    2191: - dmlist      - The `DM`s for each subdomain subproblem (or `NULL`, if not requested; if `NULL` is returned, no `DM`s are defined)

    2193:   Level: intermediate

    2195:   Notes:
    2196:   Each `IS` contains the global indices of the dofs of the corresponding subdomains with in the
    2197:   dofs of the original `DM`. The inner subdomains conceptually define a nonoverlapping
    2198:   covering, while outer subdomains can overlap.

    2200:   The optional list of `DM`s define a `DM` for each subproblem.

    2202:   The user is responsible for freeing all requested arrays. In particular, every entry of `namelist` should be freed with
    2203:   `PetscFree()`, every entry of `innerislist` and `outerislist` should be destroyed with `ISDestroy()`, every entry of `dmlist` should be destroyed with `DMDestroy()`,
    2204:   and all of the arrays should be freed with `PetscFree()`.

    2206:   Developer Notes:
    2207:   The `dmlist` is for the inner subdomains or the outer subdomains or all subdomains?

    2209:   The names are inconsistent, the hooks use `DMSubDomainHook` which is nothing like `DMCreateDomainDecomposition()` while `DMRefineHook` is used for `DMRefine()`.

    2211: .seealso: [](ch_dmbase), `DM`, `DMCreateFieldDecomposition()`, `DMDestroy()`, `DMCreateDomainDecompositionScatters()`, `DMView()`, `DMCreateInterpolation()`,
    2212:           `DMSubDomainHookAdd()`, `DMSubDomainHookRemove()`,`DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMRefine()`, `DMCoarsen()`
    2213: @*/
    2214: PetscErrorCode DMCreateDomainDecomposition(DM dm, PetscInt *n, char ***namelist, IS *innerislist[], IS *outerislist[], DM *dmlist[])
    2215: {
    2216:   DMSubDomainHookLink link;
    2217:   PetscInt            i, l;

    2219:   PetscFunctionBegin;
    2221:   if (n) {
    2222:     PetscAssertPointer(n, 2);
    2223:     *n = 0;
    2224:   }
    2225:   if (namelist) {
    2226:     PetscAssertPointer(namelist, 3);
    2227:     *namelist = NULL;
    2228:   }
    2229:   if (innerislist) {
    2230:     PetscAssertPointer(innerislist, 4);
    2231:     *innerislist = NULL;
    2232:   }
    2233:   if (outerislist) {
    2234:     PetscAssertPointer(outerislist, 5);
    2235:     *outerislist = NULL;
    2236:   }
    2237:   if (dmlist) {
    2238:     PetscAssertPointer(dmlist, 6);
    2239:     *dmlist = NULL;
    2240:   }
    2241:   /*
    2242:    Is it a good idea to apply the following check across all impls?
    2243:    Perhaps some impls can have a well-defined decomposition before DMSetUp?
    2244:    This, however, follows the general principle that accessors are not well-behaved until the object is set up.
    2245:    */
    2246:   PetscCheck(dm->setupcalled, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Decomposition defined only after DMSetUp");
    2247:   if (dm->ops->createdomaindecomposition) {
    2248:     PetscUseTypeMethod(dm, createdomaindecomposition, &l, namelist, innerislist, outerislist, dmlist);
    2249:     /* copy subdomain hooks and context over to the subdomain DMs */
    2250:     if (dmlist && *dmlist) {
    2251:       for (i = 0; i < l; i++) {
    2252:         for (link = dm->subdomainhook; link; link = link->next) {
    2253:           if (link->ddhook) PetscCall((*link->ddhook)(dm, (*dmlist)[i], link->ctx));
    2254:         }
    2255:         if (dm->ctx) (*dmlist)[i]->ctx = dm->ctx;
    2256:       }
    2257:     }
    2258:     if (n) *n = l;
    2259:   }
    2260:   PetscFunctionReturn(PETSC_SUCCESS);
    2261: }

    2263: /*@C
    2264:   DMCreateDomainDecompositionScatters - Returns scatters to the subdomain vectors from the global vector for subdomains created with
    2265:   `DMCreateDomainDecomposition()`

    2267:   Not Collective

    2269:   Input Parameters:
    2270: + dm     - the `DM` object
    2271: . n      - the number of subdomains
    2272: - subdms - the local subdomains

    2274:   Output Parameters:
    2275: + iscat - scatter from global vector to nonoverlapping global vector entries on subdomain
    2276: . oscat - scatter from global vector to overlapping global vector entries on subdomain
    2277: - gscat - scatter from global vector to local vector on subdomain (fills in ghosts)

    2279:   Level: developer

    2281:   Note:
    2282:   This is an alternative to the iis and ois arguments in `DMCreateDomainDecomposition()` that allow for the solution
    2283:   of general nonlinear problems with overlapping subdomain methods.  While merely having index sets that enable subsets
    2284:   of the residual equations to be created is fine for linear problems, nonlinear problems require local assembly of
    2285:   solution and residual data.

    2287:   Developer Note:
    2288:   Can the subdms input be anything or are they exactly the `DM` obtained from
    2289:   `DMCreateDomainDecomposition()`?

    2291: .seealso: [](ch_dmbase), `DM`, `DMCreateDomainDecomposition()`, `DMDestroy()`, `DMView()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMCreateFieldIS()`
    2292: @*/
    2293: PetscErrorCode DMCreateDomainDecompositionScatters(DM dm, PetscInt n, DM *subdms, VecScatter *iscat[], VecScatter *oscat[], VecScatter *gscat[])
    2294: {
    2295:   PetscFunctionBegin;
    2297:   PetscAssertPointer(subdms, 3);
    2298:   PetscUseTypeMethod(dm, createddscatters, n, subdms, iscat, oscat, gscat);
    2299:   PetscFunctionReturn(PETSC_SUCCESS);
    2300: }

    2302: /*@
    2303:   DMRefine - Refines a `DM` object using a standard nonadaptive refinement of the underlying mesh

    2305:   Collective

    2307:   Input Parameters:
    2308: + dm   - the `DM` object
    2309: - comm - the communicator to contain the new `DM` object (or `MPI_COMM_NULL`)

    2311:   Output Parameter:
    2312: . dmf - the refined `DM`, or `NULL`

    2314:   Options Database Key:
    2315: . -dm_plex_cell_refiner <strategy> - chooses the refinement strategy, e.g. regular, tohex

    2317:   Level: developer

    2319:   Note:
    2320:   If no refinement was done, the return value is `NULL`

    2322: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateDomainDecomposition()`,
    2323:           `DMRefineHookAdd()`, `DMRefineHookRemove()`
    2324: @*/
    2325: PetscErrorCode DMRefine(DM dm, MPI_Comm comm, DM *dmf)
    2326: {
    2327:   DMRefineHookLink link;

    2329:   PetscFunctionBegin;
    2331:   PetscCall(PetscLogEventBegin(DM_Refine, dm, 0, 0, 0));
    2332:   PetscUseTypeMethod(dm, refine, comm, dmf);
    2333:   if (*dmf) {
    2334:     (*dmf)->ops->creatematrix = dm->ops->creatematrix;

    2336:     PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)dm, (PetscObject)*dmf));

    2338:     (*dmf)->ctx       = dm->ctx;
    2339:     (*dmf)->leveldown = dm->leveldown;
    2340:     (*dmf)->levelup   = dm->levelup + 1;

    2342:     PetscCall(DMSetMatType(*dmf, dm->mattype));
    2343:     for (link = dm->refinehook; link; link = link->next) {
    2344:       if (link->refinehook) PetscCall((*link->refinehook)(dm, *dmf, link->ctx));
    2345:     }
    2346:   }
    2347:   PetscCall(PetscLogEventEnd(DM_Refine, dm, 0, 0, 0));
    2348:   PetscFunctionReturn(PETSC_SUCCESS);
    2349: }

    2351: /*@C
    2352:   DMRefineHookAdd - adds a callback to be run when interpolating a nonlinear problem to a finer grid

    2354:   Logically Collective; No Fortran Support

    2356:   Input Parameters:
    2357: + coarse     - `DM` on which to run a hook when interpolating to a finer level
    2358: . refinehook - function to run when setting up the finer level
    2359: . interphook - function to run to update data on finer levels (once per `SNESSolve()`)
    2360: - ctx        - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    2362:   Calling sequence of `refinehook`:
    2363: + coarse - coarse level `DM`
    2364: . fine   - fine level `DM` to interpolate problem to
    2365: - ctx    - optional user-defined function context

    2367:   Calling sequence of `interphook`:
    2368: + coarse - coarse level `DM`
    2369: . interp - matrix interpolating a coarse-level solution to the finer grid
    2370: . fine   - fine level `DM` to update
    2371: - ctx    - optional user-defined function context

    2373:   Level: advanced

    2375:   Notes:
    2376:   This function is only needed if auxiliary data that is attached to the `DM`s via, for example, `PetscObjectCompose()`, needs to be
    2377:   passed to fine grids while grid sequencing.

    2379:   The actual interpolation is done when `DMInterpolate()` is called.

    2381:   If this function is called multiple times, the hooks will be run in the order they are added.

    2383: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `DMInterpolate()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    2384: @*/
    2385: PetscErrorCode DMRefineHookAdd(DM coarse, PetscErrorCode (*refinehook)(DM coarse, DM fine, void *ctx), PetscErrorCode (*interphook)(DM coarse, Mat interp, DM fine, void *ctx), void *ctx)
    2386: {
    2387:   DMRefineHookLink link, *p;

    2389:   PetscFunctionBegin;
    2391:   for (p = &coarse->refinehook; *p; p = &(*p)->next) { /* Scan to the end of the current list of hooks */
    2392:     if ((*p)->refinehook == refinehook && (*p)->interphook == interphook && (*p)->ctx == ctx) PetscFunctionReturn(PETSC_SUCCESS);
    2393:   }
    2394:   PetscCall(PetscNew(&link));
    2395:   link->refinehook = refinehook;
    2396:   link->interphook = interphook;
    2397:   link->ctx        = ctx;
    2398:   link->next       = NULL;
    2399:   *p               = link;
    2400:   PetscFunctionReturn(PETSC_SUCCESS);
    2401: }

    2403: /*@C
    2404:   DMRefineHookRemove - remove a callback from the list of hooks, that have been set with `DMRefineHookAdd()`, to be run when interpolating
    2405:   a nonlinear problem to a finer grid

    2407:   Logically Collective; No Fortran Support

    2409:   Input Parameters:
    2410: + coarse     - the `DM` on which to run a hook when restricting to a coarser level
    2411: . refinehook - function to run when setting up a finer level
    2412: . interphook - function to run to update data on finer levels
    2413: - ctx        - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    2415:   Level: advanced

    2417:   Note:
    2418:   This function does nothing if the hook is not in the list.

    2420: .seealso: [](ch_dmbase), `DM`, `DMRefineHookAdd()`, `DMCoarsenHookRemove()`, `DMInterpolate()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    2421: @*/
    2422: PetscErrorCode DMRefineHookRemove(DM coarse, PetscErrorCode (*refinehook)(DM, DM, void *), PetscErrorCode (*interphook)(DM, Mat, DM, void *), void *ctx)
    2423: {
    2424:   DMRefineHookLink link, *p;

    2426:   PetscFunctionBegin;
    2428:   for (p = &coarse->refinehook; *p; p = &(*p)->next) { /* Search the list of current hooks */
    2429:     if ((*p)->refinehook == refinehook && (*p)->interphook == interphook && (*p)->ctx == ctx) {
    2430:       link = *p;
    2431:       *p   = link->next;
    2432:       PetscCall(PetscFree(link));
    2433:       break;
    2434:     }
    2435:   }
    2436:   PetscFunctionReturn(PETSC_SUCCESS);
    2437: }

    2439: /*@
    2440:   DMInterpolate - interpolates user-defined problem data attached to a `DM` to a finer `DM` by running hooks registered by `DMRefineHookAdd()`

    2442:   Collective if any hooks are

    2444:   Input Parameters:
    2445: + coarse - coarser `DM` to use as a base
    2446: . interp - interpolation matrix, apply using `MatInterpolate()`
    2447: - fine   - finer `DM` to update

    2449:   Level: developer

    2451:   Developer Note:
    2452:   This routine is called `DMInterpolate()` while the hook is called `DMRefineHookAdd()`. It would be better to have an
    2453:   an API with consistent terminology.

    2455: .seealso: [](ch_dmbase), `DM`, `DMRefineHookAdd()`, `MatInterpolate()`
    2456: @*/
    2457: PetscErrorCode DMInterpolate(DM coarse, Mat interp, DM fine)
    2458: {
    2459:   DMRefineHookLink link;

    2461:   PetscFunctionBegin;
    2462:   for (link = fine->refinehook; link; link = link->next) {
    2463:     if (link->interphook) PetscCall((*link->interphook)(coarse, interp, fine, link->ctx));
    2464:   }
    2465:   PetscFunctionReturn(PETSC_SUCCESS);
    2466: }

    2468: /*@
    2469:   DMInterpolateSolution - Interpolates a solution from a coarse mesh to a fine mesh.

    2471:   Collective

    2473:   Input Parameters:
    2474: + coarse    - coarse `DM`
    2475: . fine      - fine `DM`
    2476: . interp    - (optional) the matrix computed by `DMCreateInterpolation()`.  Implementations may not need this, but if it
    2477:             is available it can avoid some recomputation.  If it is provided, `MatInterpolate()` will be used if
    2478:             the coarse `DM` does not have a specialized implementation.
    2479: - coarseSol - solution on the coarse mesh

    2481:   Output Parameter:
    2482: . fineSol - the interpolation of coarseSol to the fine mesh

    2484:   Level: developer

    2486:   Note:
    2487:   This function exists because the interpolation of a solution vector between meshes is not always a linear
    2488:   map.  For example, if a boundary value problem has an inhomogeneous Dirichlet boundary condition that is compressed
    2489:   out of the solution vector.  Or if interpolation is inherently a nonlinear operation, such as a method using
    2490:   slope-limiting reconstruction.

    2492:   Developer Note:
    2493:   This doesn't just interpolate "solutions" so its API name is questionable.

    2495: .seealso: [](ch_dmbase), `DM`, `DMInterpolate()`, `DMCreateInterpolation()`
    2496: @*/
    2497: PetscErrorCode DMInterpolateSolution(DM coarse, DM fine, Mat interp, Vec coarseSol, Vec fineSol)
    2498: {
    2499:   PetscErrorCode (*interpsol)(DM, DM, Mat, Vec, Vec) = NULL;

    2501:   PetscFunctionBegin;

    2507:   PetscCall(PetscObjectQueryFunction((PetscObject)coarse, "DMInterpolateSolution_C", &interpsol));
    2508:   if (interpsol) {
    2509:     PetscCall((*interpsol)(coarse, fine, interp, coarseSol, fineSol));
    2510:   } else if (interp) {
    2511:     PetscCall(MatInterpolate(interp, coarseSol, fineSol));
    2512:   } else SETERRQ(PetscObjectComm((PetscObject)coarse), PETSC_ERR_SUP, "DM %s does not implement DMInterpolateSolution()", ((PetscObject)coarse)->type_name);
    2513:   PetscFunctionReturn(PETSC_SUCCESS);
    2514: }

    2516: /*@
    2517:   DMGetRefineLevel - Gets the number of refinements that have generated this `DM` from some initial `DM`.

    2519:   Not Collective

    2521:   Input Parameter:
    2522: . dm - the `DM` object

    2524:   Output Parameter:
    2525: . level - number of refinements

    2527:   Level: developer

    2529:   Note:
    2530:   This can be used, by example, to set the number of coarser levels associated with this `DM` for a multigrid solver.

    2532: .seealso: [](ch_dmbase), `DM`, `DMRefine()`, `DMCoarsen()`, `DMGetCoarsenLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    2533: @*/
    2534: PetscErrorCode DMGetRefineLevel(DM dm, PetscInt *level)
    2535: {
    2536:   PetscFunctionBegin;
    2538:   *level = dm->levelup;
    2539:   PetscFunctionReturn(PETSC_SUCCESS);
    2540: }

    2542: /*@
    2543:   DMSetRefineLevel - Sets the number of refinements that have generated this `DM`.

    2545:   Not Collective

    2547:   Input Parameters:
    2548: + dm    - the `DM` object
    2549: - level - number of refinements

    2551:   Level: advanced

    2553:   Notes:
    2554:   This value is used by `PCMG` to determine how many multigrid levels to use

    2556:   The values are usually set automatically by the process that is causing the refinements of an initial `DM` by calling this routine.

    2558: .seealso: [](ch_dmbase), `DM`, `DMGetRefineLevel()`, `DMCoarsen()`, `DMGetCoarsenLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    2559: @*/
    2560: PetscErrorCode DMSetRefineLevel(DM dm, PetscInt level)
    2561: {
    2562:   PetscFunctionBegin;
    2564:   dm->levelup = level;
    2565:   PetscFunctionReturn(PETSC_SUCCESS);
    2566: }

    2568: /*@
    2569:   DMExtrude - Extrude a `DM` object from a surface

    2571:   Collective

    2573:   Input Parameters:
    2574: + dm     - the `DM` object
    2575: - layers - the number of extruded cell layers

    2577:   Output Parameter:
    2578: . dme - the extruded `DM`, or `NULL`

    2580:   Level: developer

    2582:   Note:
    2583:   If no extrusion was done, the return value is `NULL`

    2585: .seealso: [](ch_dmbase), `DM`, `DMRefine()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`
    2586: @*/
    2587: PetscErrorCode DMExtrude(DM dm, PetscInt layers, DM *dme)
    2588: {
    2589:   PetscFunctionBegin;
    2591:   PetscUseTypeMethod(dm, extrude, layers, dme);
    2592:   if (*dme) {
    2593:     (*dme)->ops->creatematrix = dm->ops->creatematrix;
    2594:     PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)dm, (PetscObject)*dme));
    2595:     (*dme)->ctx = dm->ctx;
    2596:     PetscCall(DMSetMatType(*dme, dm->mattype));
    2597:   }
    2598:   PetscFunctionReturn(PETSC_SUCCESS);
    2599: }

    2601: PetscErrorCode DMGetBasisTransformDM_Internal(DM dm, DM *tdm)
    2602: {
    2603:   PetscFunctionBegin;
    2605:   PetscAssertPointer(tdm, 2);
    2606:   *tdm = dm->transformDM;
    2607:   PetscFunctionReturn(PETSC_SUCCESS);
    2608: }

    2610: PetscErrorCode DMGetBasisTransformVec_Internal(DM dm, Vec *tv)
    2611: {
    2612:   PetscFunctionBegin;
    2614:   PetscAssertPointer(tv, 2);
    2615:   *tv = dm->transform;
    2616:   PetscFunctionReturn(PETSC_SUCCESS);
    2617: }

    2619: /*@
    2620:   DMHasBasisTransform - Whether the `DM` employs a basis transformation from functions in global vectors to functions in local vectors

    2622:   Input Parameter:
    2623: . dm - The `DM`

    2625:   Output Parameter:
    2626: . flg - `PETSC_TRUE` if a basis transformation should be done

    2628:   Level: developer

    2630: .seealso: [](ch_dmbase), `DM`, `DMPlexGlobalToLocalBasis()`, `DMPlexLocalToGlobalBasis()`, `DMPlexCreateBasisRotation()`
    2631: @*/
    2632: PetscErrorCode DMHasBasisTransform(DM dm, PetscBool *flg)
    2633: {
    2634:   Vec tv;

    2636:   PetscFunctionBegin;
    2638:   PetscAssertPointer(flg, 2);
    2639:   PetscCall(DMGetBasisTransformVec_Internal(dm, &tv));
    2640:   *flg = tv ? PETSC_TRUE : PETSC_FALSE;
    2641:   PetscFunctionReturn(PETSC_SUCCESS);
    2642: }

    2644: PetscErrorCode DMConstructBasisTransform_Internal(DM dm)
    2645: {
    2646:   PetscSection s, ts;
    2647:   PetscScalar *ta;
    2648:   PetscInt     cdim, pStart, pEnd, p, Nf, f, Nc, dof;

    2650:   PetscFunctionBegin;
    2651:   PetscCall(DMGetCoordinateDim(dm, &cdim));
    2652:   PetscCall(DMGetLocalSection(dm, &s));
    2653:   PetscCall(PetscSectionGetChart(s, &pStart, &pEnd));
    2654:   PetscCall(PetscSectionGetNumFields(s, &Nf));
    2655:   PetscCall(DMClone(dm, &dm->transformDM));
    2656:   PetscCall(DMGetLocalSection(dm->transformDM, &ts));
    2657:   PetscCall(PetscSectionSetNumFields(ts, Nf));
    2658:   PetscCall(PetscSectionSetChart(ts, pStart, pEnd));
    2659:   for (f = 0; f < Nf; ++f) {
    2660:     PetscCall(PetscSectionGetFieldComponents(s, f, &Nc));
    2661:     /* We could start to label fields by their transformation properties */
    2662:     if (Nc != cdim) continue;
    2663:     for (p = pStart; p < pEnd; ++p) {
    2664:       PetscCall(PetscSectionGetFieldDof(s, p, f, &dof));
    2665:       if (!dof) continue;
    2666:       PetscCall(PetscSectionSetFieldDof(ts, p, f, PetscSqr(cdim)));
    2667:       PetscCall(PetscSectionAddDof(ts, p, PetscSqr(cdim)));
    2668:     }
    2669:   }
    2670:   PetscCall(PetscSectionSetUp(ts));
    2671:   PetscCall(DMCreateLocalVector(dm->transformDM, &dm->transform));
    2672:   PetscCall(VecGetArray(dm->transform, &ta));
    2673:   for (p = pStart; p < pEnd; ++p) {
    2674:     for (f = 0; f < Nf; ++f) {
    2675:       PetscCall(PetscSectionGetFieldDof(ts, p, f, &dof));
    2676:       if (dof) {
    2677:         PetscReal          x[3] = {0.0, 0.0, 0.0};
    2678:         PetscScalar       *tva;
    2679:         const PetscScalar *A;

    2681:         /* TODO Get quadrature point for this dual basis vector for coordinate */
    2682:         PetscCall((*dm->transformGetMatrix)(dm, x, PETSC_TRUE, &A, dm->transformCtx));
    2683:         PetscCall(DMPlexPointLocalFieldRef(dm->transformDM, p, f, ta, (void *)&tva));
    2684:         PetscCall(PetscArraycpy(tva, A, PetscSqr(cdim)));
    2685:       }
    2686:     }
    2687:   }
    2688:   PetscCall(VecRestoreArray(dm->transform, &ta));
    2689:   PetscFunctionReturn(PETSC_SUCCESS);
    2690: }

    2692: PetscErrorCode DMCopyTransform(DM dm, DM newdm)
    2693: {
    2694:   PetscFunctionBegin;
    2697:   newdm->transformCtx       = dm->transformCtx;
    2698:   newdm->transformSetUp     = dm->transformSetUp;
    2699:   newdm->transformDestroy   = NULL;
    2700:   newdm->transformGetMatrix = dm->transformGetMatrix;
    2701:   if (newdm->transformSetUp) PetscCall(DMConstructBasisTransform_Internal(newdm));
    2702:   PetscFunctionReturn(PETSC_SUCCESS);
    2703: }

    2705: /*@C
    2706:   DMGlobalToLocalHookAdd - adds a callback to be run when `DMGlobalToLocal()` is called

    2708:   Logically Collective

    2710:   Input Parameters:
    2711: + dm        - the `DM`
    2712: . beginhook - function to run at the beginning of `DMGlobalToLocalBegin()`
    2713: . endhook   - function to run after `DMGlobalToLocalEnd()` has completed
    2714: - ctx       - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    2716:   Calling sequence of `beginhook`:
    2717: + dm   - global `DM`
    2718: . g    - global vector
    2719: . mode - mode
    2720: . l    - local vector
    2721: - ctx  - optional user-defined function context

    2723:   Calling sequence of `endhook`:
    2724: + dm   - global `DM`
    2725: . g    - global vector
    2726: . mode - mode
    2727: . l    - local vector
    2728: - ctx  - optional user-defined function context

    2730:   Level: advanced

    2732:   Note:
    2733:   The hook may be used to provide, for example, values that represent boundary conditions in the local vectors that do not exist on the global vector.

    2735: .seealso: [](ch_dmbase), `DM`, `DMGlobalToLocal()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    2736: @*/
    2737: PetscErrorCode DMGlobalToLocalHookAdd(DM dm, PetscErrorCode (*beginhook)(DM dm, Vec g, InsertMode mode, Vec l, void *ctx), PetscErrorCode (*endhook)(DM dm, Vec g, InsertMode mode, Vec l, void *ctx), void *ctx)
    2738: {
    2739:   DMGlobalToLocalHookLink link, *p;

    2741:   PetscFunctionBegin;
    2743:   for (p = &dm->gtolhook; *p; p = &(*p)->next) { } /* Scan to the end of the current list of hooks */
    2744:   PetscCall(PetscNew(&link));
    2745:   link->beginhook = beginhook;
    2746:   link->endhook   = endhook;
    2747:   link->ctx       = ctx;
    2748:   link->next      = NULL;
    2749:   *p              = link;
    2750:   PetscFunctionReturn(PETSC_SUCCESS);
    2751: }

    2753: static PetscErrorCode DMGlobalToLocalHook_Constraints(DM dm, Vec g, InsertMode mode, Vec l, void *ctx)
    2754: {
    2755:   Mat          cMat;
    2756:   Vec          cVec, cBias;
    2757:   PetscSection section, cSec;
    2758:   PetscInt     pStart, pEnd, p, dof;

    2760:   PetscFunctionBegin;
    2761:   (void)g;
    2762:   (void)ctx;
    2764:   PetscCall(DMGetDefaultConstraints(dm, &cSec, &cMat, &cBias));
    2765:   if (cMat && (mode == INSERT_VALUES || mode == INSERT_ALL_VALUES || mode == INSERT_BC_VALUES)) {
    2766:     PetscInt nRows;

    2768:     PetscCall(MatGetSize(cMat, &nRows, NULL));
    2769:     if (nRows <= 0) PetscFunctionReturn(PETSC_SUCCESS);
    2770:     PetscCall(DMGetLocalSection(dm, &section));
    2771:     PetscCall(MatCreateVecs(cMat, NULL, &cVec));
    2772:     PetscCall(MatMult(cMat, l, cVec));
    2773:     if (cBias) PetscCall(VecAXPY(cVec, 1., cBias));
    2774:     PetscCall(PetscSectionGetChart(cSec, &pStart, &pEnd));
    2775:     for (p = pStart; p < pEnd; p++) {
    2776:       PetscCall(PetscSectionGetDof(cSec, p, &dof));
    2777:       if (dof) {
    2778:         PetscScalar *vals;
    2779:         PetscCall(VecGetValuesSection(cVec, cSec, p, &vals));
    2780:         PetscCall(VecSetValuesSection(l, section, p, vals, INSERT_ALL_VALUES));
    2781:       }
    2782:     }
    2783:     PetscCall(VecDestroy(&cVec));
    2784:   }
    2785:   PetscFunctionReturn(PETSC_SUCCESS);
    2786: }

    2788: /*@
    2789:   DMGlobalToLocal - update local vectors from global vector

    2791:   Neighbor-wise Collective

    2793:   Input Parameters:
    2794: + dm   - the `DM` object
    2795: . g    - the global vector
    2796: . mode - `INSERT_VALUES` or `ADD_VALUES`
    2797: - l    - the local vector

    2799:   Level: beginner

    2801:   Notes:
    2802:   The communication involved in this update can be overlapped with computation by instead using
    2803:   `DMGlobalToLocalBegin()` and `DMGlobalToLocalEnd()`.

    2805:   `DMGlobalToLocalHookAdd()` may be used to provide additional operations that are performed during the update process.

    2807: .seealso: [](ch_dmbase), `DM`, `DMGlobalToLocalHookAdd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`,
    2808:           `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`,
    2809:           `DMGlobalToLocalBegin()` `DMGlobalToLocalEnd()`
    2810: @*/
    2811: PetscErrorCode DMGlobalToLocal(DM dm, Vec g, InsertMode mode, Vec l)
    2812: {
    2813:   PetscFunctionBegin;
    2814:   PetscCall(DMGlobalToLocalBegin(dm, g, mode, l));
    2815:   PetscCall(DMGlobalToLocalEnd(dm, g, mode, l));
    2816:   PetscFunctionReturn(PETSC_SUCCESS);
    2817: }

    2819: /*@
    2820:   DMGlobalToLocalBegin - Begins updating local vectors from global vector

    2822:   Neighbor-wise Collective

    2824:   Input Parameters:
    2825: + dm   - the `DM` object
    2826: . g    - the global vector
    2827: . mode - `INSERT_VALUES` or `ADD_VALUES`
    2828: - l    - the local vector

    2830:   Level: intermediate

    2832:   Notes:
    2833:   The operation is completed with `DMGlobalToLocalEnd()`

    2835:   One can perform local computations between the `DMGlobalToLocalBegin()` and  `DMGlobalToLocalEnd()` to overlap communication and computation

    2837:   `DMGlobalToLocal()` is a short form of  `DMGlobalToLocalBegin()` and  `DMGlobalToLocalEnd()`

    2839:   `DMGlobalToLocalHookAdd()` may be used to provide additional operations that are performed during the update process.

    2841: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`
    2842: @*/
    2843: PetscErrorCode DMGlobalToLocalBegin(DM dm, Vec g, InsertMode mode, Vec l)
    2844: {
    2845:   PetscSF                 sf;
    2846:   DMGlobalToLocalHookLink link;

    2848:   PetscFunctionBegin;
    2850:   for (link = dm->gtolhook; link; link = link->next) {
    2851:     if (link->beginhook) PetscCall((*link->beginhook)(dm, g, mode, l, link->ctx));
    2852:   }
    2853:   PetscCall(DMGetSectionSF(dm, &sf));
    2854:   if (sf) {
    2855:     const PetscScalar *gArray;
    2856:     PetscScalar       *lArray;
    2857:     PetscMemType       lmtype, gmtype;

    2859:     PetscCheck(mode != ADD_VALUES, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", (int)mode);
    2860:     PetscCall(VecGetArrayAndMemType(l, &lArray, &lmtype));
    2861:     PetscCall(VecGetArrayReadAndMemType(g, &gArray, &gmtype));
    2862:     PetscCall(PetscSFBcastWithMemTypeBegin(sf, MPIU_SCALAR, gmtype, gArray, lmtype, lArray, MPI_REPLACE));
    2863:     PetscCall(VecRestoreArrayAndMemType(l, &lArray));
    2864:     PetscCall(VecRestoreArrayReadAndMemType(g, &gArray));
    2865:   } else {
    2866:     PetscUseTypeMethod(dm, globaltolocalbegin, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    2867:   }
    2868:   PetscFunctionReturn(PETSC_SUCCESS);
    2869: }

    2871: /*@
    2872:   DMGlobalToLocalEnd - Ends updating local vectors from global vector

    2874:   Neighbor-wise Collective

    2876:   Input Parameters:
    2877: + dm   - the `DM` object
    2878: . g    - the global vector
    2879: . mode - `INSERT_VALUES` or `ADD_VALUES`
    2880: - l    - the local vector

    2882:   Level: intermediate

    2884:   Note:
    2885:   See `DMGlobalToLocalBegin()` for details.

    2887: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMLocalToGlobalBegin()`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`
    2888: @*/
    2889: PetscErrorCode DMGlobalToLocalEnd(DM dm, Vec g, InsertMode mode, Vec l)
    2890: {
    2891:   PetscSF                 sf;
    2892:   const PetscScalar      *gArray;
    2893:   PetscScalar            *lArray;
    2894:   PetscBool               transform;
    2895:   DMGlobalToLocalHookLink link;
    2896:   PetscMemType            lmtype, gmtype;

    2898:   PetscFunctionBegin;
    2900:   PetscCall(DMGetSectionSF(dm, &sf));
    2901:   PetscCall(DMHasBasisTransform(dm, &transform));
    2902:   if (sf) {
    2903:     PetscCheck(mode != ADD_VALUES, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", (int)mode);

    2905:     PetscCall(VecGetArrayAndMemType(l, &lArray, &lmtype));
    2906:     PetscCall(VecGetArrayReadAndMemType(g, &gArray, &gmtype));
    2907:     PetscCall(PetscSFBcastEnd(sf, MPIU_SCALAR, gArray, lArray, MPI_REPLACE));
    2908:     PetscCall(VecRestoreArrayAndMemType(l, &lArray));
    2909:     PetscCall(VecRestoreArrayReadAndMemType(g, &gArray));
    2910:     if (transform) PetscCall(DMPlexGlobalToLocalBasis(dm, l));
    2911:   } else {
    2912:     PetscUseTypeMethod(dm, globaltolocalend, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    2913:   }
    2914:   PetscCall(DMGlobalToLocalHook_Constraints(dm, g, mode, l, NULL));
    2915:   for (link = dm->gtolhook; link; link = link->next) {
    2916:     if (link->endhook) PetscCall((*link->endhook)(dm, g, mode, l, link->ctx));
    2917:   }
    2918:   PetscFunctionReturn(PETSC_SUCCESS);
    2919: }

    2921: /*@C
    2922:   DMLocalToGlobalHookAdd - adds a callback to be run when a local to global is called

    2924:   Logically Collective

    2926:   Input Parameters:
    2927: + dm        - the `DM`
    2928: . beginhook - function to run at the beginning of `DMLocalToGlobalBegin()`
    2929: . endhook   - function to run after `DMLocalToGlobalEnd()` has completed
    2930: - ctx       - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    2932:   Calling sequence of `beginhook`:
    2933: + global - global `DM`
    2934: . l      - local vector
    2935: . mode   - mode
    2936: . g      - global vector
    2937: - ctx    - optional user-defined function context

    2939:   Calling sequence of `endhook`:
    2940: + global - global `DM`
    2941: . l      - local vector
    2942: . mode   - mode
    2943: . g      - global vector
    2944: - ctx    - optional user-defined function context

    2946:   Level: advanced

    2948: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobal()`, `DMRefineHookAdd()`, `DMGlobalToLocalHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    2949: @*/
    2950: PetscErrorCode DMLocalToGlobalHookAdd(DM dm, PetscErrorCode (*beginhook)(DM global, Vec l, InsertMode mode, Vec g, void *ctx), PetscErrorCode (*endhook)(DM global, Vec l, InsertMode mode, Vec g, void *ctx), void *ctx)
    2951: {
    2952:   DMLocalToGlobalHookLink link, *p;

    2954:   PetscFunctionBegin;
    2956:   for (p = &dm->ltoghook; *p; p = &(*p)->next) { } /* Scan to the end of the current list of hooks */
    2957:   PetscCall(PetscNew(&link));
    2958:   link->beginhook = beginhook;
    2959:   link->endhook   = endhook;
    2960:   link->ctx       = ctx;
    2961:   link->next      = NULL;
    2962:   *p              = link;
    2963:   PetscFunctionReturn(PETSC_SUCCESS);
    2964: }

    2966: static PetscErrorCode DMLocalToGlobalHook_Constraints(DM dm, Vec l, InsertMode mode, Vec g, void *ctx)
    2967: {
    2968:   PetscFunctionBegin;
    2969:   (void)g;
    2970:   (void)ctx;
    2972:   if (mode == ADD_VALUES || mode == ADD_ALL_VALUES || mode == ADD_BC_VALUES) {
    2973:     Mat          cMat;
    2974:     Vec          cVec;
    2975:     PetscInt     nRows;
    2976:     PetscSection section, cSec;
    2977:     PetscInt     pStart, pEnd, p, dof;

    2979:     PetscCall(DMGetDefaultConstraints(dm, &cSec, &cMat, NULL));
    2980:     if (!cMat) PetscFunctionReturn(PETSC_SUCCESS);

    2982:     PetscCall(MatGetSize(cMat, &nRows, NULL));
    2983:     if (nRows <= 0) PetscFunctionReturn(PETSC_SUCCESS);
    2984:     PetscCall(DMGetLocalSection(dm, &section));
    2985:     PetscCall(MatCreateVecs(cMat, NULL, &cVec));
    2986:     PetscCall(PetscSectionGetChart(cSec, &pStart, &pEnd));
    2987:     for (p = pStart; p < pEnd; p++) {
    2988:       PetscCall(PetscSectionGetDof(cSec, p, &dof));
    2989:       if (dof) {
    2990:         PetscInt     d;
    2991:         PetscScalar *vals;
    2992:         PetscCall(VecGetValuesSection(l, section, p, &vals));
    2993:         PetscCall(VecSetValuesSection(cVec, cSec, p, vals, mode));
    2994:         /* for this to be the true transpose, we have to zero the values that
    2995:          * we just extracted */
    2996:         for (d = 0; d < dof; d++) vals[d] = 0.;
    2997:       }
    2998:     }
    2999:     PetscCall(MatMultTransposeAdd(cMat, cVec, l, l));
    3000:     PetscCall(VecDestroy(&cVec));
    3001:   }
    3002:   PetscFunctionReturn(PETSC_SUCCESS);
    3003: }
    3004: /*@
    3005:   DMLocalToGlobal - updates global vectors from local vectors

    3007:   Neighbor-wise Collective

    3009:   Input Parameters:
    3010: + dm   - the `DM` object
    3011: . l    - the local vector
    3012: . mode - if `INSERT_VALUES` then no parallel communication is used, if `ADD_VALUES` then all ghost points from the same base point accumulate into that base point.
    3013: - g    - the global vector

    3015:   Level: beginner

    3017:   Notes:
    3018:   The communication involved in this update can be overlapped with computation by using
    3019:   `DMLocalToGlobalBegin()` and `DMLocalToGlobalEnd()`.

    3021:   In the `ADD_VALUES` case you normally would zero the receiving vector before beginning this operation.

    3023:   `INSERT_VALUES` is not supported for `DMDA`; in that case simply compute the values directly into a global vector instead of a local one.

    3025:   Use `DMLocalToGlobalHookAdd()` to add additional operations that are performed on the data during the update process

    3027: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobalBegin()`, `DMLocalToGlobalEnd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMGlobalToLocalEnd()`, `DMGlobalToLocalBegin()`, `DMLocalToGlobalHookAdd()`, `DMGlobaToLocallHookAdd()`
    3028: @*/
    3029: PetscErrorCode DMLocalToGlobal(DM dm, Vec l, InsertMode mode, Vec g)
    3030: {
    3031:   PetscFunctionBegin;
    3032:   PetscCall(DMLocalToGlobalBegin(dm, l, mode, g));
    3033:   PetscCall(DMLocalToGlobalEnd(dm, l, mode, g));
    3034:   PetscFunctionReturn(PETSC_SUCCESS);
    3035: }

    3037: /*@
    3038:   DMLocalToGlobalBegin - begins updating global vectors from local vectors

    3040:   Neighbor-wise Collective

    3042:   Input Parameters:
    3043: + dm   - the `DM` object
    3044: . l    - the local vector
    3045: . mode - if `INSERT_VALUES` then no parallel communication is used, if `ADD_VALUES` then all ghost points from the same base point accumulate into that base point.
    3046: - g    - the global vector

    3048:   Level: intermediate

    3050:   Notes:
    3051:   In the `ADD_VALUES` case you normally would zero the receiving vector before beginning this operation.

    3053:   `INSERT_VALUES is` not supported for `DMDA`, in that case simply compute the values directly into a global vector instead of a local one.

    3055:   Use `DMLocalToGlobalEnd()` to complete the communication process.

    3057:   `DMLocalToGlobal()` is a short form of  `DMLocalToGlobalBegin()` and  `DMLocalToGlobalEnd()`

    3059:   `DMLocalToGlobalHookAdd()` may be used to provide additional operations that are performed during the update process.

    3061: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobal()`, `DMLocalToGlobalEnd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocal()`, `DMGlobalToLocalEnd()`, `DMGlobalToLocalBegin()`
    3062: @*/
    3063: PetscErrorCode DMLocalToGlobalBegin(DM dm, Vec l, InsertMode mode, Vec g)
    3064: {
    3065:   PetscSF                 sf;
    3066:   PetscSection            s, gs;
    3067:   DMLocalToGlobalHookLink link;
    3068:   Vec                     tmpl;
    3069:   const PetscScalar      *lArray;
    3070:   PetscScalar            *gArray;
    3071:   PetscBool               isInsert, transform, l_inplace = PETSC_FALSE, g_inplace = PETSC_FALSE;
    3072:   PetscMemType            lmtype = PETSC_MEMTYPE_HOST, gmtype = PETSC_MEMTYPE_HOST;

    3074:   PetscFunctionBegin;
    3076:   for (link = dm->ltoghook; link; link = link->next) {
    3077:     if (link->beginhook) PetscCall((*link->beginhook)(dm, l, mode, g, link->ctx));
    3078:   }
    3079:   PetscCall(DMLocalToGlobalHook_Constraints(dm, l, mode, g, NULL));
    3080:   PetscCall(DMGetSectionSF(dm, &sf));
    3081:   PetscCall(DMGetLocalSection(dm, &s));
    3082:   switch (mode) {
    3083:   case INSERT_VALUES:
    3084:   case INSERT_ALL_VALUES:
    3085:   case INSERT_BC_VALUES:
    3086:     isInsert = PETSC_TRUE;
    3087:     break;
    3088:   case ADD_VALUES:
    3089:   case ADD_ALL_VALUES:
    3090:   case ADD_BC_VALUES:
    3091:     isInsert = PETSC_FALSE;
    3092:     break;
    3093:   default:
    3094:     SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", mode);
    3095:   }
    3096:   if ((sf && !isInsert) || (s && isInsert)) {
    3097:     PetscCall(DMHasBasisTransform(dm, &transform));
    3098:     if (transform) {
    3099:       PetscCall(DMGetNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3100:       PetscCall(VecCopy(l, tmpl));
    3101:       PetscCall(DMPlexLocalToGlobalBasis(dm, tmpl));
    3102:       PetscCall(VecGetArrayRead(tmpl, &lArray));
    3103:     } else if (isInsert) {
    3104:       PetscCall(VecGetArrayRead(l, &lArray));
    3105:     } else {
    3106:       PetscCall(VecGetArrayReadAndMemType(l, &lArray, &lmtype));
    3107:       l_inplace = PETSC_TRUE;
    3108:     }
    3109:     if (s && isInsert) {
    3110:       PetscCall(VecGetArray(g, &gArray));
    3111:     } else {
    3112:       PetscCall(VecGetArrayAndMemType(g, &gArray, &gmtype));
    3113:       g_inplace = PETSC_TRUE;
    3114:     }
    3115:     if (sf && !isInsert) {
    3116:       PetscCall(PetscSFReduceWithMemTypeBegin(sf, MPIU_SCALAR, lmtype, lArray, gmtype, gArray, MPIU_SUM));
    3117:     } else if (s && isInsert) {
    3118:       PetscInt gStart, pStart, pEnd, p;

    3120:       PetscCall(DMGetGlobalSection(dm, &gs));
    3121:       PetscCall(PetscSectionGetChart(s, &pStart, &pEnd));
    3122:       PetscCall(VecGetOwnershipRange(g, &gStart, NULL));
    3123:       for (p = pStart; p < pEnd; ++p) {
    3124:         PetscInt dof, gdof, cdof, gcdof, off, goff, d, e;

    3126:         PetscCall(PetscSectionGetDof(s, p, &dof));
    3127:         PetscCall(PetscSectionGetDof(gs, p, &gdof));
    3128:         PetscCall(PetscSectionGetConstraintDof(s, p, &cdof));
    3129:         PetscCall(PetscSectionGetConstraintDof(gs, p, &gcdof));
    3130:         PetscCall(PetscSectionGetOffset(s, p, &off));
    3131:         PetscCall(PetscSectionGetOffset(gs, p, &goff));
    3132:         /* Ignore off-process data and points with no global data */
    3133:         if (!gdof || goff < 0) continue;
    3134:         PetscCheck(dof == gdof, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Inconsistent sizes, p: %" PetscInt_FMT " dof: %" PetscInt_FMT " gdof: %" PetscInt_FMT " cdof: %" PetscInt_FMT " gcdof: %" PetscInt_FMT, p, dof, gdof, cdof, gcdof);
    3135:         /* If no constraints are enforced in the global vector */
    3136:         if (!gcdof) {
    3137:           for (d = 0; d < dof; ++d) gArray[goff - gStart + d] = lArray[off + d];
    3138:           /* If constraints are enforced in the global vector */
    3139:         } else if (cdof == gcdof) {
    3140:           const PetscInt *cdofs;
    3141:           PetscInt        cind = 0;

    3143:           PetscCall(PetscSectionGetConstraintIndices(s, p, &cdofs));
    3144:           for (d = 0, e = 0; d < dof; ++d) {
    3145:             if ((cind < cdof) && (d == cdofs[cind])) {
    3146:               ++cind;
    3147:               continue;
    3148:             }
    3149:             gArray[goff - gStart + e++] = lArray[off + d];
    3150:           }
    3151:         } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Inconsistent sizes, p: %" PetscInt_FMT " dof: %" PetscInt_FMT " gdof: %" PetscInt_FMT " cdof: %" PetscInt_FMT " gcdof: %" PetscInt_FMT, p, dof, gdof, cdof, gcdof);
    3152:       }
    3153:     }
    3154:     if (g_inplace) {
    3155:       PetscCall(VecRestoreArrayAndMemType(g, &gArray));
    3156:     } else {
    3157:       PetscCall(VecRestoreArray(g, &gArray));
    3158:     }
    3159:     if (transform) {
    3160:       PetscCall(VecRestoreArrayRead(tmpl, &lArray));
    3161:       PetscCall(DMRestoreNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3162:     } else if (l_inplace) {
    3163:       PetscCall(VecRestoreArrayReadAndMemType(l, &lArray));
    3164:     } else {
    3165:       PetscCall(VecRestoreArrayRead(l, &lArray));
    3166:     }
    3167:   } else {
    3168:     PetscUseTypeMethod(dm, localtoglobalbegin, l, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), g);
    3169:   }
    3170:   PetscFunctionReturn(PETSC_SUCCESS);
    3171: }

    3173: /*@
    3174:   DMLocalToGlobalEnd - updates global vectors from local vectors

    3176:   Neighbor-wise Collective

    3178:   Input Parameters:
    3179: + dm   - the `DM` object
    3180: . l    - the local vector
    3181: . mode - `INSERT_VALUES` or `ADD_VALUES`
    3182: - g    - the global vector

    3184:   Level: intermediate

    3186:   Note:
    3187:   See `DMLocalToGlobalBegin()` for full details

    3189: .seealso: [](ch_dmbase), `DM`, `DMLocalToGlobalBegin()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocalEnd()`
    3190: @*/
    3191: PetscErrorCode DMLocalToGlobalEnd(DM dm, Vec l, InsertMode mode, Vec g)
    3192: {
    3193:   PetscSF                 sf;
    3194:   PetscSection            s;
    3195:   DMLocalToGlobalHookLink link;
    3196:   PetscBool               isInsert, transform;

    3198:   PetscFunctionBegin;
    3200:   PetscCall(DMGetSectionSF(dm, &sf));
    3201:   PetscCall(DMGetLocalSection(dm, &s));
    3202:   switch (mode) {
    3203:   case INSERT_VALUES:
    3204:   case INSERT_ALL_VALUES:
    3205:     isInsert = PETSC_TRUE;
    3206:     break;
    3207:   case ADD_VALUES:
    3208:   case ADD_ALL_VALUES:
    3209:     isInsert = PETSC_FALSE;
    3210:     break;
    3211:   default:
    3212:     SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid insertion mode %d", mode);
    3213:   }
    3214:   if (sf && !isInsert) {
    3215:     const PetscScalar *lArray;
    3216:     PetscScalar       *gArray;
    3217:     Vec                tmpl;

    3219:     PetscCall(DMHasBasisTransform(dm, &transform));
    3220:     if (transform) {
    3221:       PetscCall(DMGetNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3222:       PetscCall(VecGetArrayRead(tmpl, &lArray));
    3223:     } else {
    3224:       PetscCall(VecGetArrayReadAndMemType(l, &lArray, NULL));
    3225:     }
    3226:     PetscCall(VecGetArrayAndMemType(g, &gArray, NULL));
    3227:     PetscCall(PetscSFReduceEnd(sf, MPIU_SCALAR, lArray, gArray, MPIU_SUM));
    3228:     if (transform) {
    3229:       PetscCall(VecRestoreArrayRead(tmpl, &lArray));
    3230:       PetscCall(DMRestoreNamedLocalVector(dm, "__petsc_dm_transform_local_copy", &tmpl));
    3231:     } else {
    3232:       PetscCall(VecRestoreArrayReadAndMemType(l, &lArray));
    3233:     }
    3234:     PetscCall(VecRestoreArrayAndMemType(g, &gArray));
    3235:   } else if (s && isInsert) {
    3236:   } else {
    3237:     PetscUseTypeMethod(dm, localtoglobalend, l, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), g);
    3238:   }
    3239:   for (link = dm->ltoghook; link; link = link->next) {
    3240:     if (link->endhook) PetscCall((*link->endhook)(dm, g, mode, l, link->ctx));
    3241:   }
    3242:   PetscFunctionReturn(PETSC_SUCCESS);
    3243: }

    3245: /*@
    3246:   DMLocalToLocalBegin - Begins the process of mapping values from a local vector (that include
    3247:   ghost points that contain irrelevant values) to another local vector where the ghost points
    3248:   in the second are set correctly from values on other MPI ranks.

    3250:   Neighbor-wise Collective

    3252:   Input Parameters:
    3253: + dm   - the `DM` object
    3254: . g    - the original local vector
    3255: - mode - one of `INSERT_VALUES` or `ADD_VALUES`

    3257:   Output Parameter:
    3258: . l - the local vector with correct ghost values

    3260:   Level: intermediate

    3262:   Note:
    3263:   Must be followed by `DMLocalToLocalEnd()`.

    3265: .seealso: [](ch_dmbase), `DM`, `DMLocalToLocalEnd()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`
    3266: @*/
    3267: PetscErrorCode DMLocalToLocalBegin(DM dm, Vec g, InsertMode mode, Vec l)
    3268: {
    3269:   PetscFunctionBegin;
    3273:   PetscUseTypeMethod(dm, localtolocalbegin, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    3274:   PetscFunctionReturn(PETSC_SUCCESS);
    3275: }

    3277: /*@
    3278:   DMLocalToLocalEnd - Maps from a local vector to another local vector where the ghost
    3279:   points in the second are set correctly. Must be preceded by `DMLocalToLocalBegin()`.

    3281:   Neighbor-wise Collective

    3283:   Input Parameters:
    3284: + dm   - the `DM` object
    3285: . g    - the original local vector
    3286: - mode - one of `INSERT_VALUES` or `ADD_VALUES`

    3288:   Output Parameter:
    3289: . l - the local vector with correct ghost values

    3291:   Level: intermediate

    3293: .seealso: [](ch_dmbase), `DM`, `DMLocalToLocalBegin()`, `DMCoarsen()`, `DMDestroy()`, `DMView()`, `DMCreateLocalVector()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`
    3294: @*/
    3295: PetscErrorCode DMLocalToLocalEnd(DM dm, Vec g, InsertMode mode, Vec l)
    3296: {
    3297:   PetscFunctionBegin;
    3301:   PetscUseTypeMethod(dm, localtolocalend, g, mode == INSERT_ALL_VALUES ? INSERT_VALUES : (mode == ADD_ALL_VALUES ? ADD_VALUES : mode), l);
    3302:   PetscFunctionReturn(PETSC_SUCCESS);
    3303: }

    3305: /*@
    3306:   DMCoarsen - Coarsens a `DM` object using a standard, non-adaptive coarsening of the underlying mesh

    3308:   Collective

    3310:   Input Parameters:
    3311: + dm   - the `DM` object
    3312: - comm - the communicator to contain the new `DM` object (or `MPI_COMM_NULL`)

    3314:   Output Parameter:
    3315: . dmc - the coarsened `DM`

    3317:   Level: developer

    3319: .seealso: [](ch_dmbase), `DM`, `DMRefine()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateDomainDecomposition()`,
    3320:           `DMCoarsenHookAdd()`, `DMCoarsenHookRemove()`
    3321: @*/
    3322: PetscErrorCode DMCoarsen(DM dm, MPI_Comm comm, DM *dmc)
    3323: {
    3324:   DMCoarsenHookLink link;

    3326:   PetscFunctionBegin;
    3328:   PetscCall(PetscLogEventBegin(DM_Coarsen, dm, 0, 0, 0));
    3329:   PetscUseTypeMethod(dm, coarsen, comm, dmc);
    3330:   if (*dmc) {
    3331:     (*dmc)->bind_below = dm->bind_below; /* Propagate this from parent DM; otherwise -dm_bind_below will be useless for multigrid cases. */
    3332:     PetscCall(DMSetCoarseDM(dm, *dmc));
    3333:     (*dmc)->ops->creatematrix = dm->ops->creatematrix;
    3334:     PetscCall(PetscObjectCopyFortranFunctionPointers((PetscObject)dm, (PetscObject)*dmc));
    3335:     (*dmc)->ctx       = dm->ctx;
    3336:     (*dmc)->levelup   = dm->levelup;
    3337:     (*dmc)->leveldown = dm->leveldown + 1;
    3338:     PetscCall(DMSetMatType(*dmc, dm->mattype));
    3339:     for (link = dm->coarsenhook; link; link = link->next) {
    3340:       if (link->coarsenhook) PetscCall((*link->coarsenhook)(dm, *dmc, link->ctx));
    3341:     }
    3342:   }
    3343:   PetscCall(PetscLogEventEnd(DM_Coarsen, dm, 0, 0, 0));
    3344:   PetscCheck(*dmc, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "NULL coarse mesh produced");
    3345:   PetscFunctionReturn(PETSC_SUCCESS);
    3346: }

    3348: /*@C
    3349:   DMCoarsenHookAdd - adds a callback to be run when restricting a nonlinear problem to the coarse grid

    3351:   Logically Collective; No Fortran Support

    3353:   Input Parameters:
    3354: + fine         - `DM` on which to run a hook when restricting to a coarser level
    3355: . coarsenhook  - function to run when setting up a coarser level
    3356: . restricthook - function to run to update data on coarser levels (called once per `SNESSolve()`)
    3357: - ctx          - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    3359:   Calling sequence of `coarsenhook`:
    3360: + fine   - fine level `DM`
    3361: . coarse - coarse level `DM` to restrict problem to
    3362: - ctx    - optional user-defined function context

    3364:   Calling sequence of `restricthook`:
    3365: + fine      - fine level `DM`
    3366: . mrestrict - matrix restricting a fine-level solution to the coarse grid, usually the transpose of the interpolation
    3367: . rscale    - scaling vector for restriction
    3368: . inject    - matrix restricting by injection
    3369: . coarse    - coarse level DM to update
    3370: - ctx       - optional user-defined function context

    3372:   Level: advanced

    3374:   Notes:
    3375:   This function is only needed if auxiliary data, attached to the `DM` with `PetscObjectCompose()`, needs to be set up or passed from the fine `DM` to the coarse `DM`.

    3377:   If this function is called multiple times, the hooks will be run in the order they are added.

    3379:   In order to compose with nonlinear preconditioning without duplicating storage, the hook should be implemented to
    3380:   extract the finest level information from its context (instead of from the `SNES`).

    3382:   The hooks are automatically called by `DMRestrict()`

    3384: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookRemove()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    3385: @*/
    3386: PetscErrorCode DMCoarsenHookAdd(DM fine, PetscErrorCode (*coarsenhook)(DM fine, DM coarse, void *ctx), PetscErrorCode (*restricthook)(DM fine, Mat mrestrict, Vec rscale, Mat inject, DM coarse, void *ctx), void *ctx)
    3387: {
    3388:   DMCoarsenHookLink link, *p;

    3390:   PetscFunctionBegin;
    3392:   for (p = &fine->coarsenhook; *p; p = &(*p)->next) { /* Scan to the end of the current list of hooks */
    3393:     if ((*p)->coarsenhook == coarsenhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) PetscFunctionReturn(PETSC_SUCCESS);
    3394:   }
    3395:   PetscCall(PetscNew(&link));
    3396:   link->coarsenhook  = coarsenhook;
    3397:   link->restricthook = restricthook;
    3398:   link->ctx          = ctx;
    3399:   link->next         = NULL;
    3400:   *p                 = link;
    3401:   PetscFunctionReturn(PETSC_SUCCESS);
    3402: }

    3404: /*@C
    3405:   DMCoarsenHookRemove - remove a callback set with `DMCoarsenHookAdd()`

    3407:   Logically Collective; No Fortran Support

    3409:   Input Parameters:
    3410: + fine         - `DM` on which to run a hook when restricting to a coarser level
    3411: . coarsenhook  - function to run when setting up a coarser level
    3412: . restricthook - function to run to update data on coarser levels
    3413: - ctx          - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    3415:   Level: advanced

    3417:   Notes:
    3418:   This function does nothing if the `coarsenhook` is not in the list.

    3420:   See `DMCoarsenHookAdd()` for the calling sequence of `coarsenhook` and `restricthook`

    3422: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`
    3423: @*/
    3424: PetscErrorCode DMCoarsenHookRemove(DM fine, PetscErrorCode (*coarsenhook)(DM, DM, void *), PetscErrorCode (*restricthook)(DM, Mat, Vec, Mat, DM, void *), void *ctx)
    3425: {
    3426:   DMCoarsenHookLink link, *p;

    3428:   PetscFunctionBegin;
    3430:   for (p = &fine->coarsenhook; *p; p = &(*p)->next) { /* Search the list of current hooks */
    3431:     if ((*p)->coarsenhook == coarsenhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) {
    3432:       link = *p;
    3433:       *p   = link->next;
    3434:       PetscCall(PetscFree(link));
    3435:       break;
    3436:     }
    3437:   }
    3438:   PetscFunctionReturn(PETSC_SUCCESS);
    3439: }

    3441: /*@
    3442:   DMRestrict - restricts user-defined problem data to a coarser `DM` by running hooks registered by `DMCoarsenHookAdd()`

    3444:   Collective if any hooks are

    3446:   Input Parameters:
    3447: + fine    - finer `DM` from which the data is obtained
    3448: . restrct - restriction matrix, apply using `MatRestrict()`, usually the transpose of the interpolation
    3449: . rscale  - scaling vector for restriction
    3450: . inject  - injection matrix, also use `MatRestrict()`
    3451: - coarse  - coarser `DM` to update

    3453:   Level: developer

    3455:   Developer Note:
    3456:   Though this routine is called `DMRestrict()` the hooks are added with `DMCoarsenHookAdd()`, a consistent terminology would be better

    3458: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `MatRestrict()`, `DMInterpolate()`, `DMRefineHookAdd()`
    3459: @*/
    3460: PetscErrorCode DMRestrict(DM fine, Mat restrct, Vec rscale, Mat inject, DM coarse)
    3461: {
    3462:   DMCoarsenHookLink link;

    3464:   PetscFunctionBegin;
    3465:   for (link = fine->coarsenhook; link; link = link->next) {
    3466:     if (link->restricthook) PetscCall((*link->restricthook)(fine, restrct, rscale, inject, coarse, link->ctx));
    3467:   }
    3468:   PetscFunctionReturn(PETSC_SUCCESS);
    3469: }

    3471: /*@C
    3472:   DMSubDomainHookAdd - adds a callback to be run when restricting a problem to subdomain `DM`s with `DMCreateDomainDecomposition()`

    3474:   Logically Collective; No Fortran Support

    3476:   Input Parameters:
    3477: + global       - global `DM`
    3478: . ddhook       - function to run to pass data to the decomposition `DM` upon its creation
    3479: . restricthook - function to run to update data on block solve (at the beginning of the block solve)
    3480: - ctx          - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    3482:   Calling sequence of `ddhook`:
    3483: + global - global `DM`
    3484: . block  - subdomain `DM`
    3485: - ctx    - optional user-defined function context

    3487:   Calling sequence of `restricthook`:
    3488: + global - global `DM`
    3489: . out    - scatter to the outer (with ghost and overlap points) sub vector
    3490: . in     - scatter to sub vector values only owned locally
    3491: . block  - subdomain `DM`
    3492: - ctx    - optional user-defined function context

    3494:   Level: advanced

    3496:   Notes:
    3497:   This function can be used if auxiliary data needs to be set up on subdomain `DM`s.

    3499:   If this function is called multiple times, the hooks will be run in the order they are added.

    3501:   In order to compose with nonlinear preconditioning without duplicating storage, the hook should be implemented to
    3502:   extract the global information from its context (instead of from the `SNES`).

    3504:   Developer Note:
    3505:   It is unclear what "block solve" means within the definition of `restricthook`

    3507: .seealso: [](ch_dmbase), `DM`, `DMSubDomainHookRemove()`, `DMRefineHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`, `DMCreateDomainDecomposition()`
    3508: @*/
    3509: PetscErrorCode DMSubDomainHookAdd(DM global, PetscErrorCode (*ddhook)(DM global, DM block, void *ctx), PetscErrorCode (*restricthook)(DM global, VecScatter out, VecScatter in, DM block, void *ctx), void *ctx)
    3510: {
    3511:   DMSubDomainHookLink link, *p;

    3513:   PetscFunctionBegin;
    3515:   for (p = &global->subdomainhook; *p; p = &(*p)->next) { /* Scan to the end of the current list of hooks */
    3516:     if ((*p)->ddhook == ddhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) PetscFunctionReturn(PETSC_SUCCESS);
    3517:   }
    3518:   PetscCall(PetscNew(&link));
    3519:   link->restricthook = restricthook;
    3520:   link->ddhook       = ddhook;
    3521:   link->ctx          = ctx;
    3522:   link->next         = NULL;
    3523:   *p                 = link;
    3524:   PetscFunctionReturn(PETSC_SUCCESS);
    3525: }

    3527: /*@C
    3528:   DMSubDomainHookRemove - remove a callback from the list to be run when restricting a problem to subdomain `DM`s with `DMCreateDomainDecomposition()`

    3530:   Logically Collective; No Fortran Support

    3532:   Input Parameters:
    3533: + global       - global `DM`
    3534: . ddhook       - function to run to pass data to the decomposition `DM` upon its creation
    3535: . restricthook - function to run to update data on block solve (at the beginning of the block solve)
    3536: - ctx          - [optional] user-defined context for provide data for the hooks (may be `NULL`)

    3538:   Level: advanced

    3540:   Note:
    3541:   See `DMSubDomainHookAdd()` for the calling sequences of `ddhook` and `restricthook`

    3543: .seealso: [](ch_dmbase), `DM`, `DMSubDomainHookAdd()`, `SNESFASGetInterpolation()`, `SNESFASGetInjection()`, `PetscObjectCompose()`, `PetscContainerCreate()`,
    3544:           `DMCreateDomainDecomposition()`
    3545: @*/
    3546: PetscErrorCode DMSubDomainHookRemove(DM global, PetscErrorCode (*ddhook)(DM, DM, void *), PetscErrorCode (*restricthook)(DM, VecScatter, VecScatter, DM, void *), void *ctx)
    3547: {
    3548:   DMSubDomainHookLink link, *p;

    3550:   PetscFunctionBegin;
    3552:   for (p = &global->subdomainhook; *p; p = &(*p)->next) { /* Search the list of current hooks */
    3553:     if ((*p)->ddhook == ddhook && (*p)->restricthook == restricthook && (*p)->ctx == ctx) {
    3554:       link = *p;
    3555:       *p   = link->next;
    3556:       PetscCall(PetscFree(link));
    3557:       break;
    3558:     }
    3559:   }
    3560:   PetscFunctionReturn(PETSC_SUCCESS);
    3561: }

    3563: /*@
    3564:   DMSubDomainRestrict - restricts user-defined problem data to a subdomain `DM` by running hooks registered by `DMSubDomainHookAdd()`

    3566:   Collective if any hooks are

    3568:   Input Parameters:
    3569: + global   - The global `DM` to use as a base
    3570: . oscatter - The scatter from domain global vector filling subdomain global vector with overlap
    3571: . gscatter - The scatter from domain global vector filling subdomain local vector with ghosts
    3572: - subdm    - The subdomain `DM` to update

    3574:   Level: developer

    3576: .seealso: [](ch_dmbase), `DM`, `DMCoarsenHookAdd()`, `MatRestrict()`, `DMCreateDomainDecomposition()`
    3577: @*/
    3578: PetscErrorCode DMSubDomainRestrict(DM global, VecScatter oscatter, VecScatter gscatter, DM subdm)
    3579: {
    3580:   DMSubDomainHookLink link;

    3582:   PetscFunctionBegin;
    3583:   for (link = global->subdomainhook; link; link = link->next) {
    3584:     if (link->restricthook) PetscCall((*link->restricthook)(global, oscatter, gscatter, subdm, link->ctx));
    3585:   }
    3586:   PetscFunctionReturn(PETSC_SUCCESS);
    3587: }

    3589: /*@
    3590:   DMGetCoarsenLevel - Gets the number of coarsenings that have generated this `DM`.

    3592:   Not Collective

    3594:   Input Parameter:
    3595: . dm - the `DM` object

    3597:   Output Parameter:
    3598: . level - number of coarsenings

    3600:   Level: developer

    3602: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMSetCoarsenLevel()`, `DMGetRefineLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3603: @*/
    3604: PetscErrorCode DMGetCoarsenLevel(DM dm, PetscInt *level)
    3605: {
    3606:   PetscFunctionBegin;
    3608:   PetscAssertPointer(level, 2);
    3609:   *level = dm->leveldown;
    3610:   PetscFunctionReturn(PETSC_SUCCESS);
    3611: }

    3613: /*@
    3614:   DMSetCoarsenLevel - Sets the number of coarsenings that have generated this `DM`.

    3616:   Collective

    3618:   Input Parameters:
    3619: + dm    - the `DM` object
    3620: - level - number of coarsenings

    3622:   Level: developer

    3624:   Note:
    3625:   This is rarely used directly, the information is automatically set when a `DM` is created with `DMCoarsen()`

    3627: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMGetCoarsenLevel()`, `DMGetRefineLevel()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3628: @*/
    3629: PetscErrorCode DMSetCoarsenLevel(DM dm, PetscInt level)
    3630: {
    3631:   PetscFunctionBegin;
    3633:   dm->leveldown = level;
    3634:   PetscFunctionReturn(PETSC_SUCCESS);
    3635: }

    3637: /*@
    3638:   DMRefineHierarchy - Refines a `DM` object, all levels at once

    3640:   Collective

    3642:   Input Parameters:
    3643: + dm      - the `DM` object
    3644: - nlevels - the number of levels of refinement

    3646:   Output Parameter:
    3647: . dmf - the refined `DM` hierarchy

    3649:   Level: developer

    3651: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMCoarsenHierarchy()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3652: @*/
    3653: PetscErrorCode DMRefineHierarchy(DM dm, PetscInt nlevels, DM dmf[])
    3654: {
    3655:   PetscFunctionBegin;
    3657:   PetscCheck(nlevels >= 0, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "nlevels cannot be negative");
    3658:   if (nlevels == 0) PetscFunctionReturn(PETSC_SUCCESS);
    3659:   PetscAssertPointer(dmf, 3);
    3660:   if (dm->ops->refine && !dm->ops->refinehierarchy) {
    3661:     PetscInt i;

    3663:     PetscCall(DMRefine(dm, PetscObjectComm((PetscObject)dm), &dmf[0]));
    3664:     for (i = 1; i < nlevels; i++) PetscCall(DMRefine(dmf[i - 1], PetscObjectComm((PetscObject)dm), &dmf[i]));
    3665:   } else PetscUseTypeMethod(dm, refinehierarchy, nlevels, dmf);
    3666:   PetscFunctionReturn(PETSC_SUCCESS);
    3667: }

    3669: /*@
    3670:   DMCoarsenHierarchy - Coarsens a `DM` object, all levels at once

    3672:   Collective

    3674:   Input Parameters:
    3675: + dm      - the `DM` object
    3676: - nlevels - the number of levels of coarsening

    3678:   Output Parameter:
    3679: . dmc - the coarsened `DM` hierarchy

    3681:   Level: developer

    3683: .seealso: [](ch_dmbase), `DM`, `DMCoarsen()`, `DMRefineHierarchy()`, `DMDestroy()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`
    3684: @*/
    3685: PetscErrorCode DMCoarsenHierarchy(DM dm, PetscInt nlevels, DM dmc[])
    3686: {
    3687:   PetscFunctionBegin;
    3689:   PetscCheck(nlevels >= 0, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "nlevels cannot be negative");
    3690:   if (nlevels == 0) PetscFunctionReturn(PETSC_SUCCESS);
    3691:   PetscAssertPointer(dmc, 3);
    3692:   if (dm->ops->coarsen && !dm->ops->coarsenhierarchy) {
    3693:     PetscInt i;

    3695:     PetscCall(DMCoarsen(dm, PetscObjectComm((PetscObject)dm), &dmc[0]));
    3696:     for (i = 1; i < nlevels; i++) PetscCall(DMCoarsen(dmc[i - 1], PetscObjectComm((PetscObject)dm), &dmc[i]));
    3697:   } else PetscUseTypeMethod(dm, coarsenhierarchy, nlevels, dmc);
    3698:   PetscFunctionReturn(PETSC_SUCCESS);
    3699: }

    3701: /*@C
    3702:   DMSetApplicationContextDestroy - Sets a user function that will be called to destroy the application context when the `DM` is destroyed

    3704:   Logically Collective if the function is collective

    3706:   Input Parameters:
    3707: + dm      - the `DM` object
    3708: - destroy - the destroy function, see `PetscCtxDestroyFn` for the calling sequence

    3710:   Level: intermediate

    3712: .seealso: [](ch_dmbase), `DM`, `DMSetApplicationContext()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`,
    3713:           `DMGetApplicationContext()`, `PetscCtxDestroyFn`
    3714: @*/
    3715: PetscErrorCode DMSetApplicationContextDestroy(DM dm, PetscCtxDestroyFn *destroy)
    3716: {
    3717:   PetscFunctionBegin;
    3719:   dm->ctxdestroy = destroy;
    3720:   PetscFunctionReturn(PETSC_SUCCESS);
    3721: }

    3723: /*@
    3724:   DMSetApplicationContext - Set a user context into a `DM` object

    3726:   Not Collective

    3728:   Input Parameters:
    3729: + dm  - the `DM` object
    3730: - ctx - the user context

    3732:   Level: intermediate

    3734:   Note:
    3735:   A user context is a way to pass problem specific information that is accessible whenever the `DM` is available
    3736:   In a multilevel solver, the user context is shared by all the `DM` in the hierarchy; it is thus not advisable
    3737:   to store objects that represent discretized quantities inside the context.

    3739:   Fortran Note:
    3740:   This only works when `ctx` is a Fortran derived type (it cannot be a `PetscObject`), we recommend writing a Fortran interface definition for this
    3741:   function that tells the Fortran compiler the derived data type that is passed in as the `ctx` argument. See `DMGetApplicationContext()` for
    3742:   an example.

    3744: .seealso: [](ch_dmbase), `DM`, `DMGetApplicationContext()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`
    3745: @*/
    3746: PetscErrorCode DMSetApplicationContext(DM dm, void *ctx)
    3747: {
    3748:   PetscFunctionBegin;
    3750:   dm->ctx = ctx;
    3751:   PetscFunctionReturn(PETSC_SUCCESS);
    3752: }

    3754: /*@
    3755:   DMGetApplicationContext - Gets a user context from a `DM` object provided with `DMSetApplicationContext()`

    3757:   Not Collective

    3759:   Input Parameter:
    3760: . dm - the `DM` object

    3762:   Output Parameter:
    3763: . ctx - a pointer to the user context

    3765:   Level: intermediate

    3767:   Note:
    3768:   A user context is a way to pass problem specific information that is accessible whenever the `DM` is available

    3770:   Fortran Notes:
    3771:   This only works when the context is a Fortran derived type (it cannot be a `PetscObject`) and you **must** write a Fortran interface definition for this
    3772:   function that tells the Fortran compiler the derived data type that is returned as the `ctx` argument. For example,
    3773: .vb
    3774:   Interface DMGetApplicationContext
    3775:     Subroutine DMGetApplicationContext(dm,ctx,ierr)
    3776:   #include <petsc/finclude/petscdm.h>
    3777:       use petscdm
    3778:       DM dm
    3779:       type(tUsertype), pointer :: ctx
    3780:       PetscErrorCode ierr
    3781:     End Subroutine
    3782:   End Interface DMGetApplicationContext
    3783: .ve

    3785:   The prototpye for `ctx` must be
    3786: .vb
    3787:   type(tUsertype), pointer :: ctx
    3788: .ve

    3790: .seealso: [](ch_dmbase), `DM`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`
    3791: @*/
    3792: PetscErrorCode DMGetApplicationContext(DM dm, PeCtx ctx)
    3793: {
    3794:   PetscFunctionBegin;
    3796:   *(void **)ctx = dm->ctx;
    3797:   PetscFunctionReturn(PETSC_SUCCESS);
    3798: }

    3800: /*@C
    3801:   DMSetVariableBounds - sets a function to compute the lower and upper bound vectors for `SNESVI`.

    3803:   Logically Collective

    3805:   Input Parameters:
    3806: + dm - the DM object
    3807: - f  - the function that computes variable bounds used by `SNESVI` (use `NULL` to cancel a previous function that was set)

    3809:   Level: intermediate

    3811:   Developer Note:
    3812:   Should be called `DMSetComputeVIBounds()` or something similar

    3814: .seealso: [](ch_dmbase), `DM`, `DMComputeVariableBounds()`, `DMHasVariableBounds()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMGetApplicationContext()`,
    3815:          `DMSetJacobian()`
    3816: @*/
    3817: PetscErrorCode DMSetVariableBounds(DM dm, PetscErrorCode (*f)(DM, Vec, Vec))
    3818: {
    3819:   PetscFunctionBegin;
    3821:   dm->ops->computevariablebounds = f;
    3822:   PetscFunctionReturn(PETSC_SUCCESS);
    3823: }

    3825: /*@
    3826:   DMHasVariableBounds - does the `DM` object have a variable bounds function?

    3828:   Not Collective

    3830:   Input Parameter:
    3831: . dm - the `DM` object to destroy

    3833:   Output Parameter:
    3834: . flg - `PETSC_TRUE` if the variable bounds function exists

    3836:   Level: developer

    3838: .seealso: [](ch_dmbase), `DM`, `DMComputeVariableBounds()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMGetApplicationContext()`
    3839: @*/
    3840: PetscErrorCode DMHasVariableBounds(DM dm, PetscBool *flg)
    3841: {
    3842:   PetscFunctionBegin;
    3844:   PetscAssertPointer(flg, 2);
    3845:   *flg = (dm->ops->computevariablebounds) ? PETSC_TRUE : PETSC_FALSE;
    3846:   PetscFunctionReturn(PETSC_SUCCESS);
    3847: }

    3849: /*@
    3850:   DMComputeVariableBounds - compute variable bounds used by `SNESVI`.

    3852:   Logically Collective

    3854:   Input Parameter:
    3855: . dm - the `DM` object

    3857:   Output Parameters:
    3858: + xl - lower bound
    3859: - xu - upper bound

    3861:   Level: advanced

    3863:   Note:
    3864:   This is generally not called by users. It calls the function provided by the user with DMSetVariableBounds()

    3866: .seealso: [](ch_dmbase), `DM`, `DMHasVariableBounds()`, `DMView()`, `DMCreateGlobalVector()`, `DMCreateInterpolation()`, `DMCreateColoring()`, `DMCreateMatrix()`, `DMCreateMassMatrix()`, `DMGetApplicationContext()`
    3867: @*/
    3868: PetscErrorCode DMComputeVariableBounds(DM dm, Vec xl, Vec xu)
    3869: {
    3870:   PetscFunctionBegin;
    3874:   PetscUseTypeMethod(dm, computevariablebounds, xl, xu);
    3875:   PetscFunctionReturn(PETSC_SUCCESS);
    3876: }

    3878: /*@
    3879:   DMHasColoring - does the `DM` object have a method of providing a coloring?

    3881:   Not Collective

    3883:   Input Parameter:
    3884: . dm - the DM object

    3886:   Output Parameter:
    3887: . flg - `PETSC_TRUE` if the `DM` has facilities for `DMCreateColoring()`.

    3889:   Level: developer

    3891: .seealso: [](ch_dmbase), `DM`, `DMCreateColoring()`
    3892: @*/
    3893: PetscErrorCode DMHasColoring(DM dm, PetscBool *flg)
    3894: {
    3895:   PetscFunctionBegin;
    3897:   PetscAssertPointer(flg, 2);
    3898:   *flg = (dm->ops->getcoloring) ? PETSC_TRUE : PETSC_FALSE;
    3899:   PetscFunctionReturn(PETSC_SUCCESS);
    3900: }

    3902: /*@
    3903:   DMHasCreateRestriction - does the `DM` object have a method of providing a restriction?

    3905:   Not Collective

    3907:   Input Parameter:
    3908: . dm - the `DM` object

    3910:   Output Parameter:
    3911: . flg - `PETSC_TRUE` if the `DM` has facilities for `DMCreateRestriction()`.

    3913:   Level: developer

    3915: .seealso: [](ch_dmbase), `DM`, `DMCreateRestriction()`, `DMHasCreateInterpolation()`, `DMHasCreateInjection()`
    3916: @*/
    3917: PetscErrorCode DMHasCreateRestriction(DM dm, PetscBool *flg)
    3918: {
    3919:   PetscFunctionBegin;
    3921:   PetscAssertPointer(flg, 2);
    3922:   *flg = (dm->ops->createrestriction) ? PETSC_TRUE : PETSC_FALSE;
    3923:   PetscFunctionReturn(PETSC_SUCCESS);
    3924: }

    3926: /*@
    3927:   DMHasCreateInjection - does the `DM` object have a method of providing an injection?

    3929:   Not Collective

    3931:   Input Parameter:
    3932: . dm - the `DM` object

    3934:   Output Parameter:
    3935: . flg - `PETSC_TRUE` if the `DM` has facilities for `DMCreateInjection()`.

    3937:   Level: developer

    3939: .seealso: [](ch_dmbase), `DM`, `DMCreateInjection()`, `DMHasCreateRestriction()`, `DMHasCreateInterpolation()`
    3940: @*/
    3941: PetscErrorCode DMHasCreateInjection(DM dm, PetscBool *flg)
    3942: {
    3943:   PetscFunctionBegin;
    3945:   PetscAssertPointer(flg, 2);
    3946:   if (dm->ops->hascreateinjection) PetscUseTypeMethod(dm, hascreateinjection, flg);
    3947:   else *flg = (dm->ops->createinjection) ? PETSC_TRUE : PETSC_FALSE;
    3948:   PetscFunctionReturn(PETSC_SUCCESS);
    3949: }

    3951: PetscFunctionList DMList              = NULL;
    3952: PetscBool         DMRegisterAllCalled = PETSC_FALSE;

    3954: /*@
    3955:   DMSetType - Builds a `DM`, for a particular `DM` implementation.

    3957:   Collective

    3959:   Input Parameters:
    3960: + dm     - The `DM` object
    3961: - method - The name of the `DMType`, for example `DMDA`, `DMPLEX`

    3963:   Options Database Key:
    3964: . -dm_type <type> - Sets the `DM` type; use -help for a list of available types

    3966:   Level: intermediate

    3968:   Note:
    3969:   Of the `DM` is constructed by directly calling a function to construct a particular `DM`, for example, `DMDACreate2d()` or `DMPlexCreateBoxMesh()`

    3971: .seealso: [](ch_dmbase), `DM`, `DMType`, `DMDA`, `DMPLEX`, `DMGetType()`, `DMCreate()`, `DMDACreate2d()`
    3972: @*/
    3973: PetscErrorCode DMSetType(DM dm, DMType method)
    3974: {
    3975:   PetscErrorCode (*r)(DM);
    3976:   PetscBool match;

    3978:   PetscFunctionBegin;
    3980:   PetscCall(PetscObjectTypeCompare((PetscObject)dm, method, &match));
    3981:   if (match) PetscFunctionReturn(PETSC_SUCCESS);

    3983:   PetscCall(DMRegisterAll());
    3984:   PetscCall(PetscFunctionListFind(DMList, method, &r));
    3985:   PetscCheck(r, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unknown DM type: %s", method);

    3987:   PetscTryTypeMethod(dm, destroy);
    3988:   PetscCall(PetscMemzero(dm->ops, sizeof(*dm->ops)));
    3989:   PetscCall(PetscObjectChangeTypeName((PetscObject)dm, method));
    3990:   PetscCall((*r)(dm));
    3991:   PetscFunctionReturn(PETSC_SUCCESS);
    3992: }

    3994: /*@
    3995:   DMGetType - Gets the `DM` type name (as a string) from the `DM`.

    3997:   Not Collective

    3999:   Input Parameter:
    4000: . dm - The `DM`

    4002:   Output Parameter:
    4003: . type - The `DMType` name

    4005:   Level: intermediate

    4007: .seealso: [](ch_dmbase), `DM`, `DMType`, `DMDA`, `DMPLEX`, `DMSetType()`, `DMCreate()`
    4008: @*/
    4009: PetscErrorCode DMGetType(DM dm, DMType *type)
    4010: {
    4011:   PetscFunctionBegin;
    4013:   PetscAssertPointer(type, 2);
    4014:   PetscCall(DMRegisterAll());
    4015:   *type = ((PetscObject)dm)->type_name;
    4016:   PetscFunctionReturn(PETSC_SUCCESS);
    4017: }

    4019: /*@
    4020:   DMConvert - Converts a `DM` to another `DM`, either of the same or different type.

    4022:   Collective

    4024:   Input Parameters:
    4025: + dm      - the `DM`
    4026: - newtype - new `DM` type (use "same" for the same type)

    4028:   Output Parameter:
    4029: . M - pointer to new `DM`

    4031:   Level: intermediate

    4033:   Note:
    4034:   Cannot be used to convert a sequential `DM` to a parallel or a parallel to sequential,
    4035:   the MPI communicator of the generated `DM` is always the same as the communicator
    4036:   of the input `DM`.

    4038: .seealso: [](ch_dmbase), `DM`, `DMSetType()`, `DMCreate()`, `DMClone()`
    4039: @*/
    4040: PetscErrorCode DMConvert(DM dm, DMType newtype, DM *M)
    4041: {
    4042:   DM        B;
    4043:   char      convname[256];
    4044:   PetscBool sametype /*, issame */;

    4046:   PetscFunctionBegin;
    4049:   PetscAssertPointer(M, 3);
    4050:   PetscCall(PetscObjectTypeCompare((PetscObject)dm, newtype, &sametype));
    4051:   /* PetscCall(PetscStrcmp(newtype, "same", &issame)); */
    4052:   if (sametype) {
    4053:     *M = dm;
    4054:     PetscCall(PetscObjectReference((PetscObject)dm));
    4055:     PetscFunctionReturn(PETSC_SUCCESS);
    4056:   } else {
    4057:     PetscErrorCode (*conv)(DM, DMType, DM *) = NULL;

    4059:     /*
    4060:        Order of precedence:
    4061:        1) See if a specialized converter is known to the current DM.
    4062:        2) See if a specialized converter is known to the desired DM class.
    4063:        3) See if a good general converter is registered for the desired class
    4064:        4) See if a good general converter is known for the current matrix.
    4065:        5) Use a really basic converter.
    4066:     */

    4068:     /* 1) See if a specialized converter is known to the current DM and the desired class */
    4069:     PetscCall(PetscStrncpy(convname, "DMConvert_", sizeof(convname)));
    4070:     PetscCall(PetscStrlcat(convname, ((PetscObject)dm)->type_name, sizeof(convname)));
    4071:     PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
    4072:     PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
    4073:     PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
    4074:     PetscCall(PetscObjectQueryFunction((PetscObject)dm, convname, &conv));
    4075:     if (conv) goto foundconv;

    4077:     /* 2)  See if a specialized converter is known to the desired DM class. */
    4078:     PetscCall(DMCreate(PetscObjectComm((PetscObject)dm), &B));
    4079:     PetscCall(DMSetType(B, newtype));
    4080:     PetscCall(PetscStrncpy(convname, "DMConvert_", sizeof(convname)));
    4081:     PetscCall(PetscStrlcat(convname, ((PetscObject)dm)->type_name, sizeof(convname)));
    4082:     PetscCall(PetscStrlcat(convname, "_", sizeof(convname)));
    4083:     PetscCall(PetscStrlcat(convname, newtype, sizeof(convname)));
    4084:     PetscCall(PetscStrlcat(convname, "_C", sizeof(convname)));
    4085:     PetscCall(PetscObjectQueryFunction((PetscObject)B, convname, &conv));
    4086:     if (conv) {
    4087:       PetscCall(DMDestroy(&B));
    4088:       goto foundconv;
    4089:     }

    4091: #if 0
    4092:     /* 3) See if a good general converter is registered for the desired class */
    4093:     conv = B->ops->convertfrom;
    4094:     PetscCall(DMDestroy(&B));
    4095:     if (conv) goto foundconv;

    4097:     /* 4) See if a good general converter is known for the current matrix */
    4098:     if (dm->ops->convert) {
    4099:       conv = dm->ops->convert;
    4100:     }
    4101:     if (conv) goto foundconv;
    4102: #endif

    4104:     /* 5) Use a really basic converter. */
    4105:     SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "No conversion possible between DM types %s and %s", ((PetscObject)dm)->type_name, newtype);

    4107:   foundconv:
    4108:     PetscCall(PetscLogEventBegin(DM_Convert, dm, 0, 0, 0));
    4109:     PetscCall((*conv)(dm, newtype, M));
    4110:     /* Things that are independent of DM type: We should consult DMClone() here */
    4111:     {
    4112:       const PetscReal *maxCell, *Lstart, *L;

    4114:       PetscCall(DMGetPeriodicity(dm, &maxCell, &Lstart, &L));
    4115:       PetscCall(DMSetPeriodicity(*M, maxCell, Lstart, L));
    4116:       (*M)->prealloc_only = dm->prealloc_only;
    4117:       PetscCall(PetscFree((*M)->vectype));
    4118:       PetscCall(PetscStrallocpy(dm->vectype, (char **)&(*M)->vectype));
    4119:       PetscCall(PetscFree((*M)->mattype));
    4120:       PetscCall(PetscStrallocpy(dm->mattype, (char **)&(*M)->mattype));
    4121:     }
    4122:     PetscCall(PetscLogEventEnd(DM_Convert, dm, 0, 0, 0));
    4123:   }
    4124:   PetscCall(PetscObjectStateIncrease((PetscObject)*M));
    4125:   PetscFunctionReturn(PETSC_SUCCESS);
    4126: }

    4128: /*@C
    4129:   DMRegister -  Adds a new `DM` type implementation

    4131:   Not Collective, No Fortran Support

    4133:   Input Parameters:
    4134: + sname    - The name of a new user-defined creation routine
    4135: - function - The creation routine itself

    4137:   Level: advanced

    4139:   Note:
    4140:   `DMRegister()` may be called multiple times to add several user-defined `DM`s

    4142:   Example Usage:
    4143: .vb
    4144:     DMRegister("my_da", MyDMCreate);
    4145: .ve

    4147:   Then, your `DM` type can be chosen with the procedural interface via
    4148: .vb
    4149:     DMCreate(MPI_Comm, DM *);
    4150:     DMSetType(DM,"my_da");
    4151: .ve
    4152:   or at runtime via the option
    4153: .vb
    4154:     -da_type my_da
    4155: .ve

    4157: .seealso: [](ch_dmbase), `DM`, `DMType`, `DMSetType()`, `DMRegisterAll()`, `DMRegisterDestroy()`
    4158: @*/
    4159: PetscErrorCode DMRegister(const char sname[], PetscErrorCode (*function)(DM))
    4160: {
    4161:   PetscFunctionBegin;
    4162:   PetscCall(DMInitializePackage());
    4163:   PetscCall(PetscFunctionListAdd(&DMList, sname, function));
    4164:   PetscFunctionReturn(PETSC_SUCCESS);
    4165: }

    4167: /*@
    4168:   DMLoad - Loads a DM that has been stored in binary  with `DMView()`.

    4170:   Collective

    4172:   Input Parameters:
    4173: + newdm  - the newly loaded `DM`, this needs to have been created with `DMCreate()` or
    4174:            some related function before a call to `DMLoad()`.
    4175: - viewer - binary file viewer, obtained from `PetscViewerBinaryOpen()` or
    4176:            `PETSCVIEWERHDF5` file viewer, obtained from `PetscViewerHDF5Open()`

    4178:   Level: intermediate

    4180:   Notes:
    4181:   The type is determined by the data in the file, any type set into the DM before this call is ignored.

    4183:   Using `PETSCVIEWERHDF5` type with `PETSC_VIEWER_HDF5_PETSC` format, one can save multiple `DMPLEX`
    4184:   meshes in a single HDF5 file. This in turn requires one to name the `DMPLEX` object with `PetscObjectSetName()`
    4185:   before saving it with `DMView()` and before loading it with `DMLoad()` for identification of the mesh object.

    4187: .seealso: [](ch_dmbase), `DM`, `PetscViewerBinaryOpen()`, `DMView()`, `MatLoad()`, `VecLoad()`
    4188: @*/
    4189: PetscErrorCode DMLoad(DM newdm, PetscViewer viewer)
    4190: {
    4191:   PetscBool isbinary, ishdf5;

    4193:   PetscFunctionBegin;
    4196:   PetscCall(PetscViewerCheckReadable(viewer));
    4197:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
    4198:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
    4199:   PetscCall(PetscLogEventBegin(DM_Load, viewer, 0, 0, 0));
    4200:   if (isbinary) {
    4201:     PetscInt classid;
    4202:     char     type[256];

    4204:     PetscCall(PetscViewerBinaryRead(viewer, &classid, 1, NULL, PETSC_INT));
    4205:     PetscCheck(classid == DM_FILE_CLASSID, PetscObjectComm((PetscObject)newdm), PETSC_ERR_ARG_WRONG, "Not DM next in file, classid found %" PetscInt_FMT, classid);
    4206:     PetscCall(PetscViewerBinaryRead(viewer, type, 256, NULL, PETSC_CHAR));
    4207:     PetscCall(DMSetType(newdm, type));
    4208:     PetscTryTypeMethod(newdm, load, viewer);
    4209:   } else if (ishdf5) {
    4210:     PetscTryTypeMethod(newdm, load, viewer);
    4211:   } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerBinaryOpen() or PetscViewerHDF5Open()");
    4212:   PetscCall(PetscLogEventEnd(DM_Load, viewer, 0, 0, 0));
    4213:   PetscFunctionReturn(PETSC_SUCCESS);
    4214: }

    4216: /* FEM Support */

    4218: PetscErrorCode DMPrintCellIndices(PetscInt c, const char name[], PetscInt len, const PetscInt x[])
    4219: {
    4220:   PetscInt f;

    4222:   PetscFunctionBegin;
    4223:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4224:   for (f = 0; f < len; ++f) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  | %" PetscInt_FMT " |\n", x[f]));
    4225:   PetscFunctionReturn(PETSC_SUCCESS);
    4226: }

    4228: PetscErrorCode DMPrintCellVector(PetscInt c, const char name[], PetscInt len, const PetscScalar x[])
    4229: {
    4230:   PetscInt f;

    4232:   PetscFunctionBegin;
    4233:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4234:   for (f = 0; f < len; ++f) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  | %g |\n", (double)PetscRealPart(x[f])));
    4235:   PetscFunctionReturn(PETSC_SUCCESS);
    4236: }

    4238: PetscErrorCode DMPrintCellVectorReal(PetscInt c, const char name[], PetscInt len, const PetscReal x[])
    4239: {
    4240:   PetscInt f;

    4242:   PetscFunctionBegin;
    4243:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4244:   for (f = 0; f < len; ++f) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  | %g |\n", (double)x[f]));
    4245:   PetscFunctionReturn(PETSC_SUCCESS);
    4246: }

    4248: PetscErrorCode DMPrintCellMatrix(PetscInt c, const char name[], PetscInt rows, PetscInt cols, const PetscScalar A[])
    4249: {
    4250:   PetscInt f, g;

    4252:   PetscFunctionBegin;
    4253:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "Cell %" PetscInt_FMT " Element %s\n", c, name));
    4254:   for (f = 0; f < rows; ++f) {
    4255:     PetscCall(PetscPrintf(PETSC_COMM_SELF, "  |"));
    4256:     for (g = 0; g < cols; ++g) PetscCall(PetscPrintf(PETSC_COMM_SELF, " % 9.5g", (double)PetscRealPart(A[f * cols + g])));
    4257:     PetscCall(PetscPrintf(PETSC_COMM_SELF, " |\n"));
    4258:   }
    4259:   PetscFunctionReturn(PETSC_SUCCESS);
    4260: }

    4262: PetscErrorCode DMPrintLocalVec(DM dm, const char name[], PetscReal tol, Vec X)
    4263: {
    4264:   PetscInt           localSize, bs;
    4265:   PetscMPIInt        size;
    4266:   Vec                x, xglob;
    4267:   const PetscScalar *xarray;

    4269:   PetscFunctionBegin;
    4270:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size));
    4271:   PetscCall(VecDuplicate(X, &x));
    4272:   PetscCall(VecCopy(X, x));
    4273:   PetscCall(VecFilter(x, tol));
    4274:   PetscCall(PetscPrintf(PetscObjectComm((PetscObject)dm), "%s:\n", name));
    4275:   if (size > 1) {
    4276:     PetscCall(VecGetLocalSize(x, &localSize));
    4277:     PetscCall(VecGetArrayRead(x, &xarray));
    4278:     PetscCall(VecGetBlockSize(x, &bs));
    4279:     PetscCall(VecCreateMPIWithArray(PetscObjectComm((PetscObject)dm), bs, localSize, PETSC_DETERMINE, xarray, &xglob));
    4280:   } else {
    4281:     xglob = x;
    4282:   }
    4283:   PetscCall(VecView(xglob, PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)dm))));
    4284:   if (size > 1) {
    4285:     PetscCall(VecDestroy(&xglob));
    4286:     PetscCall(VecRestoreArrayRead(x, &xarray));
    4287:   }
    4288:   PetscCall(VecDestroy(&x));
    4289:   PetscFunctionReturn(PETSC_SUCCESS);
    4290: }

    4292: /*@
    4293:   DMGetLocalSection - Get the `PetscSection` encoding the local data layout for the `DM`.

    4295:   Input Parameter:
    4296: . dm - The `DM`

    4298:   Output Parameter:
    4299: . section - The `PetscSection`

    4301:   Options Database Key:
    4302: . -dm_petscsection_view - View the section created by the `DM`

    4304:   Level: intermediate

    4306:   Note:
    4307:   This gets a borrowed reference, so the user should not destroy this `PetscSection`.

    4309: .seealso: [](ch_dmbase), `DM`, `DMSetLocalSection()`, `DMGetGlobalSection()`
    4310: @*/
    4311: PetscErrorCode DMGetLocalSection(DM dm, PetscSection *section)
    4312: {
    4313:   PetscFunctionBegin;
    4315:   PetscAssertPointer(section, 2);
    4316:   if (!dm->localSection && dm->ops->createlocalsection) {
    4317:     PetscInt d;

    4319:     if (dm->setfromoptionscalled) {
    4320:       PetscObject       obj = (PetscObject)dm;
    4321:       PetscViewer       viewer;
    4322:       PetscViewerFormat format;
    4323:       PetscBool         flg;

    4325:       PetscCall(PetscOptionsCreateViewer(PetscObjectComm(obj), obj->options, obj->prefix, "-dm_petscds_view", &viewer, &format, &flg));
    4326:       if (flg) PetscCall(PetscViewerPushFormat(viewer, format));
    4327:       for (d = 0; d < dm->Nds; ++d) {
    4328:         PetscCall(PetscDSSetFromOptions(dm->probs[d].ds));
    4329:         if (flg) PetscCall(PetscDSView(dm->probs[d].ds, viewer));
    4330:       }
    4331:       if (flg) {
    4332:         PetscCall(PetscViewerFlush(viewer));
    4333:         PetscCall(PetscViewerPopFormat(viewer));
    4334:         PetscCall(PetscViewerDestroy(&viewer));
    4335:       }
    4336:     }
    4337:     PetscUseTypeMethod(dm, createlocalsection);
    4338:     if (dm->localSection) PetscCall(PetscObjectViewFromOptions((PetscObject)dm->localSection, NULL, "-dm_petscsection_view"));
    4339:   }
    4340:   *section = dm->localSection;
    4341:   PetscFunctionReturn(PETSC_SUCCESS);
    4342: }

    4344: /*@
    4345:   DMSetLocalSection - Set the `PetscSection` encoding the local data layout for the `DM`.

    4347:   Input Parameters:
    4348: + dm      - The `DM`
    4349: - section - The `PetscSection`

    4351:   Level: intermediate

    4353:   Note:
    4354:   Any existing Section will be destroyed

    4356: .seealso: [](ch_dmbase), `DM`, `PetscSection`, `DMGetLocalSection()`, `DMSetGlobalSection()`
    4357: @*/
    4358: PetscErrorCode DMSetLocalSection(DM dm, PetscSection section)
    4359: {
    4360:   PetscInt numFields = 0;
    4361:   PetscInt f;

    4363:   PetscFunctionBegin;
    4366:   PetscCall(PetscObjectReference((PetscObject)section));
    4367:   PetscCall(PetscSectionDestroy(&dm->localSection));
    4368:   dm->localSection = section;
    4369:   if (section) PetscCall(PetscSectionGetNumFields(dm->localSection, &numFields));
    4370:   if (numFields) {
    4371:     PetscCall(DMSetNumFields(dm, numFields));
    4372:     for (f = 0; f < numFields; ++f) {
    4373:       PetscObject disc;
    4374:       const char *name;

    4376:       PetscCall(PetscSectionGetFieldName(dm->localSection, f, &name));
    4377:       PetscCall(DMGetField(dm, f, NULL, &disc));
    4378:       PetscCall(PetscObjectSetName(disc, name));
    4379:     }
    4380:   }
    4381:   /* The global section and the SectionSF will be rebuilt
    4382:      in the next call to DMGetGlobalSection() and DMGetSectionSF(). */
    4383:   PetscCall(PetscSectionDestroy(&dm->globalSection));
    4384:   PetscCall(PetscSFDestroy(&dm->sectionSF));
    4385:   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &dm->sectionSF));

    4387:   /* Clear scratch vectors */
    4388:   PetscCall(DMClearGlobalVectors(dm));
    4389:   PetscCall(DMClearLocalVectors(dm));
    4390:   PetscCall(DMClearNamedGlobalVectors(dm));
    4391:   PetscCall(DMClearNamedLocalVectors(dm));
    4392:   PetscFunctionReturn(PETSC_SUCCESS);
    4393: }

    4395: /*@C
    4396:   DMCreateSectionPermutation - Create a permutation of the `PetscSection` chart and optionally a block structure.

    4398:   Input Parameter:
    4399: . dm - The `DM`

    4401:   Output Parameters:
    4402: + perm        - A permutation of the mesh points in the chart
    4403: - blockStarts - A high bit is set for the point that begins every block, or `NULL` for default blocking

    4405:   Level: developer

    4407: .seealso: [](ch_dmbase), `DM`, `PetscSection`, `DMGetLocalSection()`, `DMGetGlobalSection()`
    4408: @*/
    4409: PetscErrorCode DMCreateSectionPermutation(DM dm, IS *perm, PetscBT *blockStarts)
    4410: {
    4411:   PetscFunctionBegin;
    4412:   *perm        = NULL;
    4413:   *blockStarts = NULL;
    4414:   PetscTryTypeMethod(dm, createsectionpermutation, perm, blockStarts);
    4415:   PetscFunctionReturn(PETSC_SUCCESS);
    4416: }

    4418: /*@
    4419:   DMGetDefaultConstraints - Get the `PetscSection` and `Mat` that specify the local constraint interpolation. See `DMSetDefaultConstraints()` for a description of the purpose of constraint interpolation.

    4421:   not Collective

    4423:   Input Parameter:
    4424: . dm - The `DM`

    4426:   Output Parameters:
    4427: + section - The `PetscSection` describing the range of the constraint matrix: relates rows of the constraint matrix to dofs of the default section.  Returns `NULL` if there are no local constraints.
    4428: . mat     - The `Mat` that interpolates local constraints: its width should be the layout size of the default section.  Returns `NULL` if there are no local constraints.
    4429: - bias    - Vector containing bias to be added to constrained dofs

    4431:   Level: advanced

    4433:   Note:
    4434:   This gets borrowed references, so the user should not destroy the `PetscSection`, `Mat`, or `Vec`.

    4436: .seealso: [](ch_dmbase), `DM`, `DMSetDefaultConstraints()`
    4437: @*/
    4438: PetscErrorCode DMGetDefaultConstraints(DM dm, PetscSection *section, Mat *mat, Vec *bias)
    4439: {
    4440:   PetscFunctionBegin;
    4442:   if (!dm->defaultConstraint.section && !dm->defaultConstraint.mat && dm->ops->createdefaultconstraints) PetscUseTypeMethod(dm, createdefaultconstraints);
    4443:   if (section) *section = dm->defaultConstraint.section;
    4444:   if (mat) *mat = dm->defaultConstraint.mat;
    4445:   if (bias) *bias = dm->defaultConstraint.bias;
    4446:   PetscFunctionReturn(PETSC_SUCCESS);
    4447: }

    4449: /*@
    4450:   DMSetDefaultConstraints - Set the `PetscSection` and `Mat` that specify the local constraint interpolation.

    4452:   Collective

    4454:   Input Parameters:
    4455: + dm      - The `DM`
    4456: . section - The `PetscSection` describing the range of the constraint matrix: relates rows of the constraint matrix to dofs of the default section.  Must have a local communicator (`PETSC_COMM_SELF` or derivative).
    4457: . mat     - The `Mat` that interpolates local constraints: its width should be the layout size of the default section:  `NULL` indicates no constraints.  Must have a local communicator (`PETSC_COMM_SELF` or derivative).
    4458: - bias    - A bias vector to be added to constrained values in the local vector.  `NULL` indicates no bias.  Must have a local communicator (`PETSC_COMM_SELF` or derivative).

    4460:   Level: advanced

    4462:   Notes:
    4463:   If a constraint matrix is specified, then it is applied during `DMGlobalToLocalEnd()` when mode is `INSERT_VALUES`, `INSERT_BC_VALUES`, or `INSERT_ALL_VALUES`.  Without a constraint matrix, the local vector l returned by `DMGlobalToLocalEnd()` contains values that have been scattered from a global vector without modification; with a constraint matrix A, l is modified by computing c = A * l + bias, l[s[i]] = c[i], where the scatter s is defined by the `PetscSection` returned by `DMGetDefaultConstraints()`.

    4465:   If a constraint matrix is specified, then its adjoint is applied during `DMLocalToGlobalBegin()` when mode is `ADD_VALUES`, `ADD_BC_VALUES`, or `ADD_ALL_VALUES`.  Without a constraint matrix, the local vector l is accumulated into a global vector without modification; with a constraint matrix A, l is first modified by computing c[i] = l[s[i]], l[s[i]] = 0, l = l + A'*c, which is the adjoint of the operation described above.  Any bias, if specified, is ignored when accumulating.

    4467:   This increments the references of the `PetscSection`, `Mat`, and `Vec`, so they user can destroy them.

    4469: .seealso: [](ch_dmbase), `DM`, `DMGetDefaultConstraints()`
    4470: @*/
    4471: PetscErrorCode DMSetDefaultConstraints(DM dm, PetscSection section, Mat mat, Vec bias)
    4472: {
    4473:   PetscMPIInt result;

    4475:   PetscFunctionBegin;
    4477:   if (section) {
    4479:     PetscCallMPI(MPI_Comm_compare(PETSC_COMM_SELF, PetscObjectComm((PetscObject)section), &result));
    4480:     PetscCheck(result == MPI_CONGRUENT || result == MPI_IDENT, PETSC_COMM_SELF, PETSC_ERR_ARG_NOTSAMECOMM, "constraint section must have local communicator");
    4481:   }
    4482:   if (mat) {
    4484:     PetscCallMPI(MPI_Comm_compare(PETSC_COMM_SELF, PetscObjectComm((PetscObject)mat), &result));
    4485:     PetscCheck(result == MPI_CONGRUENT || result == MPI_IDENT, PETSC_COMM_SELF, PETSC_ERR_ARG_NOTSAMECOMM, "constraint matrix must have local communicator");
    4486:   }
    4487:   if (bias) {
    4489:     PetscCallMPI(MPI_Comm_compare(PETSC_COMM_SELF, PetscObjectComm((PetscObject)bias), &result));
    4490:     PetscCheck(result == MPI_CONGRUENT || result == MPI_IDENT, PETSC_COMM_SELF, PETSC_ERR_ARG_NOTSAMECOMM, "constraint bias must have local communicator");
    4491:   }
    4492:   PetscCall(PetscObjectReference((PetscObject)section));
    4493:   PetscCall(PetscSectionDestroy(&dm->defaultConstraint.section));
    4494:   dm->defaultConstraint.section = section;
    4495:   PetscCall(PetscObjectReference((PetscObject)mat));
    4496:   PetscCall(MatDestroy(&dm->defaultConstraint.mat));
    4497:   dm->defaultConstraint.mat = mat;
    4498:   PetscCall(PetscObjectReference((PetscObject)bias));
    4499:   PetscCall(VecDestroy(&dm->defaultConstraint.bias));
    4500:   dm->defaultConstraint.bias = bias;
    4501:   PetscFunctionReturn(PETSC_SUCCESS);
    4502: }

    4504: #if defined(PETSC_USE_DEBUG)
    4505: /*
    4506:   DMDefaultSectionCheckConsistency - Check the consistentcy of the global and local sections. Generates and error if they are not consistent.

    4508:   Input Parameters:
    4509: + dm - The `DM`
    4510: . localSection - `PetscSection` describing the local data layout
    4511: - globalSection - `PetscSection` describing the global data layout

    4513:   Level: intermediate

    4515: .seealso: [](ch_dmbase), `DM`, `DMGetSectionSF()`, `DMSetSectionSF()`
    4516: */
    4517: static PetscErrorCode DMDefaultSectionCheckConsistency_Internal(DM dm, PetscSection localSection, PetscSection globalSection)
    4518: {
    4519:   MPI_Comm        comm;
    4520:   PetscLayout     layout;
    4521:   const PetscInt *ranges;
    4522:   PetscInt        pStart, pEnd, p, nroots;
    4523:   PetscMPIInt     size, rank;
    4524:   PetscBool       valid = PETSC_TRUE, gvalid;

    4526:   PetscFunctionBegin;
    4527:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
    4529:   PetscCallMPI(MPI_Comm_size(comm, &size));
    4530:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    4531:   PetscCall(PetscSectionGetChart(globalSection, &pStart, &pEnd));
    4532:   PetscCall(PetscSectionGetConstrainedStorageSize(globalSection, &nroots));
    4533:   PetscCall(PetscLayoutCreate(comm, &layout));
    4534:   PetscCall(PetscLayoutSetBlockSize(layout, 1));
    4535:   PetscCall(PetscLayoutSetLocalSize(layout, nroots));
    4536:   PetscCall(PetscLayoutSetUp(layout));
    4537:   PetscCall(PetscLayoutGetRanges(layout, &ranges));
    4538:   for (p = pStart; p < pEnd; ++p) {
    4539:     PetscInt dof, cdof, off, gdof, gcdof, goff, gsize, d;

    4541:     PetscCall(PetscSectionGetDof(localSection, p, &dof));
    4542:     PetscCall(PetscSectionGetOffset(localSection, p, &off));
    4543:     PetscCall(PetscSectionGetConstraintDof(localSection, p, &cdof));
    4544:     PetscCall(PetscSectionGetDof(globalSection, p, &gdof));
    4545:     PetscCall(PetscSectionGetConstraintDof(globalSection, p, &gcdof));
    4546:     PetscCall(PetscSectionGetOffset(globalSection, p, &goff));
    4547:     if (!gdof) continue; /* Censored point */
    4548:     if ((gdof < 0 ? -(gdof + 1) : gdof) != dof) {
    4549:       PetscCall(PetscSynchronizedPrintf(comm, "[%d]Global dof %" PetscInt_FMT " for point %" PetscInt_FMT " not equal to local dof %" PetscInt_FMT "\n", rank, gdof, p, dof));
    4550:       valid = PETSC_FALSE;
    4551:     }
    4552:     if (gcdof && (gcdof != cdof)) {
    4553:       PetscCall(PetscSynchronizedPrintf(comm, "[%d]Global constraints %" PetscInt_FMT " for point %" PetscInt_FMT " not equal to local constraints %" PetscInt_FMT "\n", rank, gcdof, p, cdof));
    4554:       valid = PETSC_FALSE;
    4555:     }
    4556:     if (gdof < 0) {
    4557:       gsize = gdof < 0 ? -(gdof + 1) - gcdof : gdof - gcdof;
    4558:       for (d = 0; d < gsize; ++d) {
    4559:         PetscInt offset = -(goff + 1) + d, r;

    4561:         PetscCall(PetscFindInt(offset, size + 1, ranges, &r));
    4562:         if (r < 0) r = -(r + 2);
    4563:         if ((r < 0) || (r >= size)) {
    4564:           PetscCall(PetscSynchronizedPrintf(comm, "[%d]Point %" PetscInt_FMT " mapped to invalid process %" PetscInt_FMT " (%" PetscInt_FMT ", %" PetscInt_FMT ")\n", rank, p, r, gdof, goff));
    4565:           valid = PETSC_FALSE;
    4566:           break;
    4567:         }
    4568:       }
    4569:     }
    4570:   }
    4571:   PetscCall(PetscLayoutDestroy(&layout));
    4572:   PetscCall(PetscSynchronizedFlush(comm, NULL));
    4573:   PetscCallMPI(MPIU_Allreduce(&valid, &gvalid, 1, MPIU_BOOL, MPI_LAND, comm));
    4574:   if (!gvalid) {
    4575:     PetscCall(DMView(dm, NULL));
    4576:     SETERRQ(comm, PETSC_ERR_ARG_WRONG, "Inconsistent local and global sections");
    4577:   }
    4578:   PetscFunctionReturn(PETSC_SUCCESS);
    4579: }
    4580: #endif

    4582: PetscErrorCode DMGetIsoperiodicPointSF_Internal(DM dm, PetscSF *sf)
    4583: {
    4584:   PetscErrorCode (*f)(DM, PetscSF *);

    4586:   PetscFunctionBegin;
    4588:   PetscAssertPointer(sf, 2);
    4589:   PetscCall(PetscObjectQueryFunction((PetscObject)dm, "DMGetIsoperiodicPointSF_C", &f));
    4590:   if (f) PetscCall(f(dm, sf));
    4591:   else *sf = dm->sf;
    4592:   PetscFunctionReturn(PETSC_SUCCESS);
    4593: }

    4595: /*@
    4596:   DMGetGlobalSection - Get the `PetscSection` encoding the global data layout for the `DM`.

    4598:   Collective

    4600:   Input Parameter:
    4601: . dm - The `DM`

    4603:   Output Parameter:
    4604: . section - The `PetscSection`

    4606:   Level: intermediate

    4608:   Note:
    4609:   This gets a borrowed reference, so the user should not destroy this `PetscSection`.

    4611: .seealso: [](ch_dmbase), `DM`, `DMSetLocalSection()`, `DMGetLocalSection()`
    4612: @*/
    4613: PetscErrorCode DMGetGlobalSection(DM dm, PetscSection *section)
    4614: {
    4615:   PetscFunctionBegin;
    4617:   PetscAssertPointer(section, 2);
    4618:   if (!dm->globalSection) {
    4619:     PetscSection s;
    4620:     PetscSF      sf;

    4622:     PetscCall(DMGetLocalSection(dm, &s));
    4623:     PetscCheck(s, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "DM must have a default PetscSection in order to create a global PetscSection");
    4624:     PetscCheck(dm->sf, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "DM must have a point PetscSF in order to create a global PetscSection");
    4625:     PetscCall(DMGetIsoperiodicPointSF_Internal(dm, &sf));
    4626:     PetscCall(PetscSectionCreateGlobalSection(s, sf, PETSC_TRUE, PETSC_FALSE, PETSC_FALSE, &dm->globalSection));
    4627:     PetscCall(PetscLayoutDestroy(&dm->map));
    4628:     PetscCall(PetscSectionGetValueLayout(PetscObjectComm((PetscObject)dm), dm->globalSection, &dm->map));
    4629:     PetscCall(PetscSectionViewFromOptions(dm->globalSection, NULL, "-global_section_view"));
    4630:   }
    4631:   *section = dm->globalSection;
    4632:   PetscFunctionReturn(PETSC_SUCCESS);
    4633: }

    4635: /*@
    4636:   DMSetGlobalSection - Set the `PetscSection` encoding the global data layout for the `DM`.

    4638:   Input Parameters:
    4639: + dm      - The `DM`
    4640: - section - The PetscSection, or `NULL`

    4642:   Level: intermediate

    4644:   Note:
    4645:   Any existing `PetscSection` will be destroyed

    4647: .seealso: [](ch_dmbase), `DM`, `DMGetGlobalSection()`, `DMSetLocalSection()`
    4648: @*/
    4649: PetscErrorCode DMSetGlobalSection(DM dm, PetscSection section)
    4650: {
    4651:   PetscFunctionBegin;
    4654:   PetscCall(PetscObjectReference((PetscObject)section));
    4655:   PetscCall(PetscSectionDestroy(&dm->globalSection));
    4656:   dm->globalSection = section;
    4657: #if defined(PETSC_USE_DEBUG)
    4658:   if (section) PetscCall(DMDefaultSectionCheckConsistency_Internal(dm, dm->localSection, section));
    4659: #endif
    4660:   /* Clear global scratch vectors and sectionSF */
    4661:   PetscCall(PetscSFDestroy(&dm->sectionSF));
    4662:   PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &dm->sectionSF));
    4663:   PetscCall(DMClearGlobalVectors(dm));
    4664:   PetscCall(DMClearNamedGlobalVectors(dm));
    4665:   PetscFunctionReturn(PETSC_SUCCESS);
    4666: }

    4668: /*@
    4669:   DMGetSectionSF - Get the `PetscSF` encoding the parallel dof overlap for the `DM`. If it has not been set,
    4670:   it is created from the default `PetscSection` layouts in the `DM`.

    4672:   Input Parameter:
    4673: . dm - The `DM`

    4675:   Output Parameter:
    4676: . sf - The `PetscSF`

    4678:   Level: intermediate

    4680:   Note:
    4681:   This gets a borrowed reference, so the user should not destroy this `PetscSF`.

    4683: .seealso: [](ch_dmbase), `DM`, `DMSetSectionSF()`, `DMCreateSectionSF()`
    4684: @*/
    4685: PetscErrorCode DMGetSectionSF(DM dm, PetscSF *sf)
    4686: {
    4687:   PetscInt nroots;

    4689:   PetscFunctionBegin;
    4691:   PetscAssertPointer(sf, 2);
    4692:   if (!dm->sectionSF) PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &dm->sectionSF));
    4693:   PetscCall(PetscSFGetGraph(dm->sectionSF, &nroots, NULL, NULL, NULL));
    4694:   if (nroots < 0) {
    4695:     PetscSection section, gSection;

    4697:     PetscCall(DMGetLocalSection(dm, &section));
    4698:     if (section) {
    4699:       PetscCall(DMGetGlobalSection(dm, &gSection));
    4700:       PetscCall(DMCreateSectionSF(dm, section, gSection));
    4701:     } else {
    4702:       *sf = NULL;
    4703:       PetscFunctionReturn(PETSC_SUCCESS);
    4704:     }
    4705:   }
    4706:   *sf = dm->sectionSF;
    4707:   PetscFunctionReturn(PETSC_SUCCESS);
    4708: }

    4710: /*@
    4711:   DMSetSectionSF - Set the `PetscSF` encoding the parallel dof overlap for the `DM`

    4713:   Input Parameters:
    4714: + dm - The `DM`
    4715: - sf - The `PetscSF`

    4717:   Level: intermediate

    4719:   Note:
    4720:   Any previous `PetscSF` is destroyed

    4722: .seealso: [](ch_dmbase), `DM`, `DMGetSectionSF()`, `DMCreateSectionSF()`
    4723: @*/
    4724: PetscErrorCode DMSetSectionSF(DM dm, PetscSF sf)
    4725: {
    4726:   PetscFunctionBegin;
    4729:   PetscCall(PetscObjectReference((PetscObject)sf));
    4730:   PetscCall(PetscSFDestroy(&dm->sectionSF));
    4731:   dm->sectionSF = sf;
    4732:   PetscFunctionReturn(PETSC_SUCCESS);
    4733: }

    4735: /*@
    4736:   DMCreateSectionSF - Create the `PetscSF` encoding the parallel dof overlap for the `DM` based upon the `PetscSection`s
    4737:   describing the data layout.

    4739:   Input Parameters:
    4740: + dm            - The `DM`
    4741: . localSection  - `PetscSection` describing the local data layout
    4742: - globalSection - `PetscSection` describing the global data layout

    4744:   Level: developer

    4746:   Note:
    4747:   One usually uses `DMGetSectionSF()` to obtain the `PetscSF`

    4749:   Developer Note:
    4750:   Since this routine has for arguments the two sections from the `DM` and puts the resulting `PetscSF`
    4751:   directly into the `DM`, perhaps this function should not take the local and global sections as
    4752:   input and should just obtain them from the `DM`? Plus PETSc creation functions return the thing
    4753:   they create, this returns nothing

    4755: .seealso: [](ch_dmbase), `DM`, `DMGetSectionSF()`, `DMSetSectionSF()`, `DMGetLocalSection()`, `DMGetGlobalSection()`
    4756: @*/
    4757: PetscErrorCode DMCreateSectionSF(DM dm, PetscSection localSection, PetscSection globalSection)
    4758: {
    4759:   PetscFunctionBegin;
    4761:   PetscCall(PetscSFSetGraphSection(dm->sectionSF, localSection, globalSection));
    4762:   PetscFunctionReturn(PETSC_SUCCESS);
    4763: }

    4765: /*@
    4766:   DMGetPointSF - Get the `PetscSF` encoding the parallel section point overlap for the `DM`.

    4768:   Not collective but the resulting `PetscSF` is collective

    4770:   Input Parameter:
    4771: . dm - The `DM`

    4773:   Output Parameter:
    4774: . sf - The `PetscSF`

    4776:   Level: intermediate

    4778:   Note:
    4779:   This gets a borrowed reference, so the user should not destroy this `PetscSF`.

    4781: .seealso: [](ch_dmbase), `DM`, `DMSetPointSF()`, `DMGetSectionSF()`, `DMSetSectionSF()`, `DMCreateSectionSF()`
    4782: @*/
    4783: PetscErrorCode DMGetPointSF(DM dm, PetscSF *sf)
    4784: {
    4785:   PetscFunctionBegin;
    4787:   PetscAssertPointer(sf, 2);
    4788:   *sf = dm->sf;
    4789:   PetscFunctionReturn(PETSC_SUCCESS);
    4790: }

    4792: /*@
    4793:   DMSetPointSF - Set the `PetscSF` encoding the parallel section point overlap for the `DM`.

    4795:   Collective

    4797:   Input Parameters:
    4798: + dm - The `DM`
    4799: - sf - The `PetscSF`

    4801:   Level: intermediate

    4803: .seealso: [](ch_dmbase), `DM`, `DMGetPointSF()`, `DMGetSectionSF()`, `DMSetSectionSF()`, `DMCreateSectionSF()`
    4804: @*/
    4805: PetscErrorCode DMSetPointSF(DM dm, PetscSF sf)
    4806: {
    4807:   PetscFunctionBegin;
    4810:   PetscCall(PetscObjectReference((PetscObject)sf));
    4811:   PetscCall(PetscSFDestroy(&dm->sf));
    4812:   dm->sf = sf;
    4813:   PetscFunctionReturn(PETSC_SUCCESS);
    4814: }

    4816: /*@
    4817:   DMGetNaturalSF - Get the `PetscSF` encoding the map back to the original mesh ordering

    4819:   Input Parameter:
    4820: . dm - The `DM`

    4822:   Output Parameter:
    4823: . sf - The `PetscSF`

    4825:   Level: intermediate

    4827:   Note:
    4828:   This gets a borrowed reference, so the user should not destroy this `PetscSF`.

    4830: .seealso: [](ch_dmbase), `DM`, `DMSetNaturalSF()`, `DMSetUseNatural()`, `DMGetUseNatural()`, `DMPlexCreateGlobalToNaturalSF()`, `DMPlexDistribute()`
    4831: @*/
    4832: PetscErrorCode DMGetNaturalSF(DM dm, PetscSF *sf)
    4833: {
    4834:   PetscFunctionBegin;
    4836:   PetscAssertPointer(sf, 2);
    4837:   *sf = dm->sfNatural;
    4838:   PetscFunctionReturn(PETSC_SUCCESS);
    4839: }

    4841: /*@
    4842:   DMSetNaturalSF - Set the PetscSF encoding the map back to the original mesh ordering

    4844:   Input Parameters:
    4845: + dm - The DM
    4846: - sf - The PetscSF

    4848:   Level: intermediate

    4850: .seealso: [](ch_dmbase), `DM`, `DMGetNaturalSF()`, `DMSetUseNatural()`, `DMGetUseNatural()`, `DMPlexCreateGlobalToNaturalSF()`, `DMPlexDistribute()`
    4851: @*/
    4852: PetscErrorCode DMSetNaturalSF(DM dm, PetscSF sf)
    4853: {
    4854:   PetscFunctionBegin;
    4857:   PetscCall(PetscObjectReference((PetscObject)sf));
    4858:   PetscCall(PetscSFDestroy(&dm->sfNatural));
    4859:   dm->sfNatural = sf;
    4860:   PetscFunctionReturn(PETSC_SUCCESS);
    4861: }

    4863: static PetscErrorCode DMSetDefaultAdjacency_Private(DM dm, PetscInt f, PetscObject disc)
    4864: {
    4865:   PetscClassId id;

    4867:   PetscFunctionBegin;
    4868:   PetscCall(PetscObjectGetClassId(disc, &id));
    4869:   if (id == PETSCFE_CLASSID) {
    4870:     PetscCall(DMSetAdjacency(dm, f, PETSC_FALSE, PETSC_TRUE));
    4871:   } else if (id == PETSCFV_CLASSID) {
    4872:     PetscCall(DMSetAdjacency(dm, f, PETSC_TRUE, PETSC_FALSE));
    4873:   } else {
    4874:     PetscCall(DMSetAdjacency(dm, f, PETSC_FALSE, PETSC_TRUE));
    4875:   }
    4876:   PetscFunctionReturn(PETSC_SUCCESS);
    4877: }

    4879: static PetscErrorCode DMFieldEnlarge_Static(DM dm, PetscInt NfNew)
    4880: {
    4881:   RegionField *tmpr;
    4882:   PetscInt     Nf = dm->Nf, f;

    4884:   PetscFunctionBegin;
    4885:   if (Nf >= NfNew) PetscFunctionReturn(PETSC_SUCCESS);
    4886:   PetscCall(PetscMalloc1(NfNew, &tmpr));
    4887:   for (f = 0; f < Nf; ++f) tmpr[f] = dm->fields[f];
    4888:   for (f = Nf; f < NfNew; ++f) {
    4889:     tmpr[f].disc        = NULL;
    4890:     tmpr[f].label       = NULL;
    4891:     tmpr[f].avoidTensor = PETSC_FALSE;
    4892:   }
    4893:   PetscCall(PetscFree(dm->fields));
    4894:   dm->Nf     = NfNew;
    4895:   dm->fields = tmpr;
    4896:   PetscFunctionReturn(PETSC_SUCCESS);
    4897: }

    4899: /*@
    4900:   DMClearFields - Remove all fields from the `DM`

    4902:   Logically Collective

    4904:   Input Parameter:
    4905: . dm - The `DM`

    4907:   Level: intermediate

    4909: .seealso: [](ch_dmbase), `DM`, `DMGetNumFields()`, `DMSetNumFields()`, `DMSetField()`
    4910: @*/
    4911: PetscErrorCode DMClearFields(DM dm)
    4912: {
    4913:   PetscInt f;

    4915:   PetscFunctionBegin;
    4917:   for (f = 0; f < dm->Nf; ++f) {
    4918:     PetscCall(PetscObjectDestroy(&dm->fields[f].disc));
    4919:     PetscCall(DMLabelDestroy(&dm->fields[f].label));
    4920:   }
    4921:   PetscCall(PetscFree(dm->fields));
    4922:   dm->fields = NULL;
    4923:   dm->Nf     = 0;
    4924:   PetscFunctionReturn(PETSC_SUCCESS);
    4925: }

    4927: /*@
    4928:   DMGetNumFields - Get the number of fields in the `DM`

    4930:   Not Collective

    4932:   Input Parameter:
    4933: . dm - The `DM`

    4935:   Output Parameter:
    4936: . numFields - The number of fields

    4938:   Level: intermediate

    4940: .seealso: [](ch_dmbase), `DM`, `DMSetNumFields()`, `DMSetField()`
    4941: @*/
    4942: PetscErrorCode DMGetNumFields(DM dm, PetscInt *numFields)
    4943: {
    4944:   PetscFunctionBegin;
    4946:   PetscAssertPointer(numFields, 2);
    4947:   *numFields = dm->Nf;
    4948:   PetscFunctionReturn(PETSC_SUCCESS);
    4949: }

    4951: /*@
    4952:   DMSetNumFields - Set the number of fields in the `DM`

    4954:   Logically Collective

    4956:   Input Parameters:
    4957: + dm        - The `DM`
    4958: - numFields - The number of fields

    4960:   Level: intermediate

    4962: .seealso: [](ch_dmbase), `DM`, `DMGetNumFields()`, `DMSetField()`
    4963: @*/
    4964: PetscErrorCode DMSetNumFields(DM dm, PetscInt numFields)
    4965: {
    4966:   PetscInt Nf, f;

    4968:   PetscFunctionBegin;
    4970:   PetscCall(DMGetNumFields(dm, &Nf));
    4971:   for (f = Nf; f < numFields; ++f) {
    4972:     PetscContainer obj;

    4974:     PetscCall(PetscContainerCreate(PetscObjectComm((PetscObject)dm), &obj));
    4975:     PetscCall(DMAddField(dm, NULL, (PetscObject)obj));
    4976:     PetscCall(PetscContainerDestroy(&obj));
    4977:   }
    4978:   PetscFunctionReturn(PETSC_SUCCESS);
    4979: }

    4981: /*@
    4982:   DMGetField - Return the `DMLabel` and discretization object for a given `DM` field

    4984:   Not Collective

    4986:   Input Parameters:
    4987: + dm - The `DM`
    4988: - f  - The field number

    4990:   Output Parameters:
    4991: + label - The label indicating the support of the field, or `NULL` for the entire mesh (pass in `NULL` if not needed)
    4992: - disc  - The discretization object (pass in `NULL` if not needed)

    4994:   Level: intermediate

    4996: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMSetField()`
    4997: @*/
    4998: PetscErrorCode DMGetField(DM dm, PetscInt f, DMLabel *label, PetscObject *disc)
    4999: {
    5000:   PetscFunctionBegin;
    5002:   PetscAssertPointer(disc, 4);
    5003:   PetscCheck((f >= 0) && (f < dm->Nf), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", f, dm->Nf);
    5004:   if (label) *label = dm->fields[f].label;
    5005:   if (disc) *disc = dm->fields[f].disc;
    5006:   PetscFunctionReturn(PETSC_SUCCESS);
    5007: }

    5009: /* Does not clear the DS */
    5010: PetscErrorCode DMSetField_Internal(DM dm, PetscInt f, DMLabel label, PetscObject disc)
    5011: {
    5012:   PetscFunctionBegin;
    5013:   PetscCall(DMFieldEnlarge_Static(dm, f + 1));
    5014:   PetscCall(DMLabelDestroy(&dm->fields[f].label));
    5015:   PetscCall(PetscObjectDestroy(&dm->fields[f].disc));
    5016:   dm->fields[f].label = label;
    5017:   dm->fields[f].disc  = disc;
    5018:   PetscCall(PetscObjectReference((PetscObject)label));
    5019:   PetscCall(PetscObjectReference(disc));
    5020:   PetscFunctionReturn(PETSC_SUCCESS);
    5021: }

    5023: /*@
    5024:   DMSetField - Set the discretization object for a given `DM` field. Usually one would call `DMAddField()` which automatically handles
    5025:   the field numbering.

    5027:   Logically Collective

    5029:   Input Parameters:
    5030: + dm    - The `DM`
    5031: . f     - The field number
    5032: . label - The label indicating the support of the field, or `NULL` for the entire mesh
    5033: - disc  - The discretization object

    5035:   Level: intermediate

    5037: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMGetField()`
    5038: @*/
    5039: PetscErrorCode DMSetField(DM dm, PetscInt f, DMLabel label, PetscObject disc)
    5040: {
    5041:   PetscFunctionBegin;
    5045:   PetscCheck(f >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be non-negative", f);
    5046:   PetscCall(DMSetField_Internal(dm, f, label, disc));
    5047:   PetscCall(DMSetDefaultAdjacency_Private(dm, f, disc));
    5048:   PetscCall(DMClearDS(dm));
    5049:   PetscFunctionReturn(PETSC_SUCCESS);
    5050: }

    5052: /*@
    5053:   DMAddField - Add a field to a `DM` object. A field is a function space defined by of a set of discretization points (geometric entities)
    5054:   and a discretization object that defines the function space associated with those points.

    5056:   Logically Collective

    5058:   Input Parameters:
    5059: + dm    - The `DM`
    5060: . label - The label indicating the support of the field, or `NULL` for the entire mesh
    5061: - disc  - The discretization object

    5063:   Level: intermediate

    5065:   Notes:
    5066:   The label already exists or will be added to the `DM` with `DMSetLabel()`.

    5068:   For example, a piecewise continuous pressure field can be defined by coefficients at the cell centers of a mesh and piecewise constant functions
    5069:   within each cell. Thus a specific function in the space is defined by the combination of a `Vec` containing the coefficients, a `DM` defining the
    5070:   geometry entities, a `DMLabel` indicating a subset of those geometric entities, and a discretization object, such as a `PetscFE`.

    5072:   Fortran Note:
    5073:   Use the argument `PetscObjectCast(disc)` as the second argument

    5075: .seealso: [](ch_dmbase), `DM`, `DMSetLabel()`, `DMSetField()`, `DMGetField()`, `PetscFE`
    5076: @*/
    5077: PetscErrorCode DMAddField(DM dm, DMLabel label, PetscObject disc)
    5078: {
    5079:   PetscInt Nf = dm->Nf;

    5081:   PetscFunctionBegin;
    5085:   PetscCall(DMFieldEnlarge_Static(dm, Nf + 1));
    5086:   dm->fields[Nf].label = label;
    5087:   dm->fields[Nf].disc  = disc;
    5088:   PetscCall(PetscObjectReference((PetscObject)label));
    5089:   PetscCall(PetscObjectReference(disc));
    5090:   PetscCall(DMSetDefaultAdjacency_Private(dm, Nf, disc));
    5091:   PetscCall(DMClearDS(dm));
    5092:   PetscFunctionReturn(PETSC_SUCCESS);
    5093: }

    5095: /*@
    5096:   DMSetFieldAvoidTensor - Set flag to avoid defining the field on tensor cells

    5098:   Logically Collective

    5100:   Input Parameters:
    5101: + dm          - The `DM`
    5102: . f           - The field index
    5103: - avoidTensor - `PETSC_TRUE` to skip defining the field on tensor cells

    5105:   Level: intermediate

    5107: .seealso: [](ch_dmbase), `DM`, `DMGetFieldAvoidTensor()`, `DMSetField()`, `DMGetField()`
    5108: @*/
    5109: PetscErrorCode DMSetFieldAvoidTensor(DM dm, PetscInt f, PetscBool avoidTensor)
    5110: {
    5111:   PetscFunctionBegin;
    5112:   PetscCheck((f >= 0) && (f < dm->Nf), PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Field %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", f, dm->Nf);
    5113:   dm->fields[f].avoidTensor = avoidTensor;
    5114:   PetscFunctionReturn(PETSC_SUCCESS);
    5115: }

    5117: /*@
    5118:   DMGetFieldAvoidTensor - Get flag to avoid defining the field on tensor cells

    5120:   Not Collective

    5122:   Input Parameters:
    5123: + dm - The `DM`
    5124: - f  - The field index

    5126:   Output Parameter:
    5127: . avoidTensor - The flag to avoid defining the field on tensor cells

    5129:   Level: intermediate

    5131: .seealso: [](ch_dmbase), `DM`, `DMAddField()`, `DMSetField()`, `DMGetField()`, `DMSetFieldAvoidTensor()`
    5132: @*/
    5133: PetscErrorCode DMGetFieldAvoidTensor(DM dm, PetscInt f, PetscBool *avoidTensor)
    5134: {
    5135:   PetscFunctionBegin;
    5136:   PetscCheck((f >= 0) && (f < dm->Nf), PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Field %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", f, dm->Nf);
    5137:   *avoidTensor = dm->fields[f].avoidTensor;
    5138:   PetscFunctionReturn(PETSC_SUCCESS);
    5139: }

    5141: /*@
    5142:   DMCopyFields - Copy the discretizations for the `DM` into another `DM`

    5144:   Collective

    5146:   Input Parameters:
    5147: + dm        - The `DM`
    5148: . minDegree - Minimum degree for a discretization, or `PETSC_DETERMINE` for no limit
    5149: - maxDegree - Maximum degree for a discretization, or `PETSC_DETERMINE` for no limit

    5151:   Output Parameter:
    5152: . newdm - The `DM`

    5154:   Level: advanced

    5156: .seealso: [](ch_dmbase), `DM`, `DMGetField()`, `DMSetField()`, `DMAddField()`, `DMCopyDS()`, `DMGetDS()`, `DMGetCellDS()`
    5157: @*/
    5158: PetscErrorCode DMCopyFields(DM dm, PetscInt minDegree, PetscInt maxDegree, DM newdm)
    5159: {
    5160:   PetscInt Nf, f;

    5162:   PetscFunctionBegin;
    5163:   if (dm == newdm) PetscFunctionReturn(PETSC_SUCCESS);
    5164:   PetscCall(DMGetNumFields(dm, &Nf));
    5165:   PetscCall(DMClearFields(newdm));
    5166:   for (f = 0; f < Nf; ++f) {
    5167:     DMLabel      label;
    5168:     PetscObject  field;
    5169:     PetscClassId id;
    5170:     PetscBool    useCone, useClosure;

    5172:     PetscCall(DMGetField(dm, f, &label, &field));
    5173:     PetscCall(PetscObjectGetClassId(field, &id));
    5174:     if (id == PETSCFE_CLASSID) {
    5175:       PetscFE newfe;

    5177:       PetscCall(PetscFELimitDegree((PetscFE)field, minDegree, maxDegree, &newfe));
    5178:       PetscCall(DMSetField(newdm, f, label, (PetscObject)newfe));
    5179:       PetscCall(PetscFEDestroy(&newfe));
    5180:     } else {
    5181:       PetscCall(DMSetField(newdm, f, label, field));
    5182:     }
    5183:     PetscCall(DMGetAdjacency(dm, f, &useCone, &useClosure));
    5184:     PetscCall(DMSetAdjacency(newdm, f, useCone, useClosure));
    5185:   }
    5186:   PetscFunctionReturn(PETSC_SUCCESS);
    5187: }

    5189: /*@
    5190:   DMGetAdjacency - Returns the flags for determining variable influence

    5192:   Not Collective

    5194:   Input Parameters:
    5195: + dm - The `DM` object
    5196: - f  - The field number, or `PETSC_DEFAULT` for the default adjacency

    5198:   Output Parameters:
    5199: + useCone    - Flag for variable influence starting with the cone operation
    5200: - useClosure - Flag for variable influence using transitive closure

    5202:   Level: developer

    5204:   Notes:
    5205: .vb
    5206:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5207:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5208:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5209: .ve
    5210:   Further explanation can be found in the User's Manual Section on the Influence of Variables on One Another.

    5212: .seealso: [](ch_dmbase), `DM`, `DMSetAdjacency()`, `DMGetField()`, `DMSetField()`
    5213: @*/
    5214: PetscErrorCode DMGetAdjacency(DM dm, PetscInt f, PetscBool *useCone, PetscBool *useClosure)
    5215: {
    5216:   PetscFunctionBegin;
    5218:   if (useCone) PetscAssertPointer(useCone, 3);
    5219:   if (useClosure) PetscAssertPointer(useClosure, 4);
    5220:   if (f < 0) {
    5221:     if (useCone) *useCone = dm->adjacency[0];
    5222:     if (useClosure) *useClosure = dm->adjacency[1];
    5223:   } else {
    5224:     PetscInt Nf;

    5226:     PetscCall(DMGetNumFields(dm, &Nf));
    5227:     PetscCheck(f < Nf, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", f, Nf);
    5228:     if (useCone) *useCone = dm->fields[f].adjacency[0];
    5229:     if (useClosure) *useClosure = dm->fields[f].adjacency[1];
    5230:   }
    5231:   PetscFunctionReturn(PETSC_SUCCESS);
    5232: }

    5234: /*@
    5235:   DMSetAdjacency - Set the flags for determining variable influence

    5237:   Not Collective

    5239:   Input Parameters:
    5240: + dm         - The `DM` object
    5241: . f          - The field number
    5242: . useCone    - Flag for variable influence starting with the cone operation
    5243: - useClosure - Flag for variable influence using transitive closure

    5245:   Level: developer

    5247:   Notes:
    5248: .vb
    5249:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5250:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5251:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5252: .ve
    5253:   Further explanation can be found in the User's Manual Section on the Influence of Variables on One Another.

    5255: .seealso: [](ch_dmbase), `DM`, `DMGetAdjacency()`, `DMGetField()`, `DMSetField()`
    5256: @*/
    5257: PetscErrorCode DMSetAdjacency(DM dm, PetscInt f, PetscBool useCone, PetscBool useClosure)
    5258: {
    5259:   PetscFunctionBegin;
    5261:   if (f < 0) {
    5262:     dm->adjacency[0] = useCone;
    5263:     dm->adjacency[1] = useClosure;
    5264:   } else {
    5265:     PetscInt Nf;

    5267:     PetscCall(DMGetNumFields(dm, &Nf));
    5268:     PetscCheck(f < Nf, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Field number %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", f, Nf);
    5269:     dm->fields[f].adjacency[0] = useCone;
    5270:     dm->fields[f].adjacency[1] = useClosure;
    5271:   }
    5272:   PetscFunctionReturn(PETSC_SUCCESS);
    5273: }

    5275: /*@
    5276:   DMGetBasicAdjacency - Returns the flags for determining variable influence, using either the default or field 0 if it is defined

    5278:   Not collective

    5280:   Input Parameter:
    5281: . dm - The `DM` object

    5283:   Output Parameters:
    5284: + useCone    - Flag for variable influence starting with the cone operation
    5285: - useClosure - Flag for variable influence using transitive closure

    5287:   Level: developer

    5289:   Notes:
    5290: .vb
    5291:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5292:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5293:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5294: .ve

    5296: .seealso: [](ch_dmbase), `DM`, `DMSetBasicAdjacency()`, `DMGetField()`, `DMSetField()`
    5297: @*/
    5298: PetscErrorCode DMGetBasicAdjacency(DM dm, PetscBool *useCone, PetscBool *useClosure)
    5299: {
    5300:   PetscInt Nf;

    5302:   PetscFunctionBegin;
    5304:   if (useCone) PetscAssertPointer(useCone, 2);
    5305:   if (useClosure) PetscAssertPointer(useClosure, 3);
    5306:   PetscCall(DMGetNumFields(dm, &Nf));
    5307:   if (!Nf) {
    5308:     PetscCall(DMGetAdjacency(dm, PETSC_DEFAULT, useCone, useClosure));
    5309:   } else {
    5310:     PetscCall(DMGetAdjacency(dm, 0, useCone, useClosure));
    5311:   }
    5312:   PetscFunctionReturn(PETSC_SUCCESS);
    5313: }

    5315: /*@
    5316:   DMSetBasicAdjacency - Set the flags for determining variable influence, using either the default or field 0 if it is defined

    5318:   Not Collective

    5320:   Input Parameters:
    5321: + dm         - The `DM` object
    5322: . useCone    - Flag for variable influence starting with the cone operation
    5323: - useClosure - Flag for variable influence using transitive closure

    5325:   Level: developer

    5327:   Notes:
    5328: .vb
    5329:      FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
    5330:      FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
    5331:      FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE
    5332: .ve

    5334: .seealso: [](ch_dmbase), `DM`, `DMGetBasicAdjacency()`, `DMGetField()`, `DMSetField()`
    5335: @*/
    5336: PetscErrorCode DMSetBasicAdjacency(DM dm, PetscBool useCone, PetscBool useClosure)
    5337: {
    5338:   PetscInt Nf;

    5340:   PetscFunctionBegin;
    5342:   PetscCall(DMGetNumFields(dm, &Nf));
    5343:   if (!Nf) {
    5344:     PetscCall(DMSetAdjacency(dm, PETSC_DEFAULT, useCone, useClosure));
    5345:   } else {
    5346:     PetscCall(DMSetAdjacency(dm, 0, useCone, useClosure));
    5347:   }
    5348:   PetscFunctionReturn(PETSC_SUCCESS);
    5349: }

    5351: PetscErrorCode DMCompleteBCLabels_Internal(DM dm)
    5352: {
    5353:   DM           plex;
    5354:   DMLabel     *labels, *glabels;
    5355:   const char **names;
    5356:   char        *sendNames, *recvNames;
    5357:   PetscInt     Nds, s, maxLabels = 0, maxLen = 0, gmaxLen, Nl = 0, gNl, l, gl, m;
    5358:   size_t       len;
    5359:   MPI_Comm     comm;
    5360:   PetscMPIInt  rank, size, p, *counts, *displs;

    5362:   PetscFunctionBegin;
    5363:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
    5364:   PetscCallMPI(MPI_Comm_size(comm, &size));
    5365:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    5366:   PetscCall(DMGetNumDS(dm, &Nds));
    5367:   for (s = 0; s < Nds; ++s) {
    5368:     PetscDS  dsBC;
    5369:     PetscInt numBd;

    5371:     PetscCall(DMGetRegionNumDS(dm, s, NULL, NULL, &dsBC, NULL));
    5372:     PetscCall(PetscDSGetNumBoundary(dsBC, &numBd));
    5373:     maxLabels += numBd;
    5374:   }
    5375:   PetscCall(PetscCalloc1(maxLabels, &labels));
    5376:   /* Get list of labels to be completed */
    5377:   for (s = 0; s < Nds; ++s) {
    5378:     PetscDS  dsBC;
    5379:     PetscInt numBd, bd;

    5381:     PetscCall(DMGetRegionNumDS(dm, s, NULL, NULL, &dsBC, NULL));
    5382:     PetscCall(PetscDSGetNumBoundary(dsBC, &numBd));
    5383:     for (bd = 0; bd < numBd; ++bd) {
    5384:       DMLabel      label;
    5385:       PetscInt     field;
    5386:       PetscObject  obj;
    5387:       PetscClassId id;

    5389:       PetscCall(PetscDSGetBoundary(dsBC, bd, NULL, NULL, NULL, &label, NULL, NULL, &field, NULL, NULL, NULL, NULL, NULL));
    5390:       PetscCall(DMGetField(dm, field, NULL, &obj));
    5391:       PetscCall(PetscObjectGetClassId(obj, &id));
    5392:       if (id != PETSCFE_CLASSID || !label) continue;
    5393:       for (l = 0; l < Nl; ++l)
    5394:         if (labels[l] == label) break;
    5395:       if (l == Nl) labels[Nl++] = label;
    5396:     }
    5397:   }
    5398:   /* Get label names */
    5399:   PetscCall(PetscMalloc1(Nl, &names));
    5400:   for (l = 0; l < Nl; ++l) PetscCall(PetscObjectGetName((PetscObject)labels[l], &names[l]));
    5401:   for (l = 0; l < Nl; ++l) {
    5402:     PetscCall(PetscStrlen(names[l], &len));
    5403:     maxLen = PetscMax(maxLen, (PetscInt)len + 2);
    5404:   }
    5405:   PetscCall(PetscFree(labels));
    5406:   PetscCallMPI(MPIU_Allreduce(&maxLen, &gmaxLen, 1, MPIU_INT, MPI_MAX, comm));
    5407:   PetscCall(PetscCalloc1(Nl * gmaxLen, &sendNames));
    5408:   for (l = 0; l < Nl; ++l) PetscCall(PetscStrncpy(&sendNames[gmaxLen * l], names[l], gmaxLen));
    5409:   PetscCall(PetscFree(names));
    5410:   /* Put all names on all processes */
    5411:   PetscCall(PetscCalloc2(size, &counts, size + 1, &displs));
    5412:   PetscCallMPI(MPI_Allgather(&Nl, 1, MPI_INT, counts, 1, MPI_INT, comm));
    5413:   for (p = 0; p < size; ++p) displs[p + 1] = displs[p] + counts[p];
    5414:   gNl = displs[size];
    5415:   for (p = 0; p < size; ++p) {
    5416:     counts[p] *= gmaxLen;
    5417:     displs[p] *= gmaxLen;
    5418:   }
    5419:   PetscCall(PetscCalloc2(gNl * gmaxLen, &recvNames, gNl, &glabels));
    5420:   PetscCallMPI(MPI_Allgatherv(sendNames, counts[rank], MPI_CHAR, recvNames, counts, displs, MPI_CHAR, comm));
    5421:   PetscCall(PetscFree2(counts, displs));
    5422:   PetscCall(PetscFree(sendNames));
    5423:   for (l = 0, gl = 0; l < gNl; ++l) {
    5424:     PetscCall(DMGetLabel(dm, &recvNames[l * gmaxLen], &glabels[gl]));
    5425:     PetscCheck(glabels[gl], PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Label %s missing on rank %d", &recvNames[l * gmaxLen], rank);
    5426:     for (m = 0; m < gl; ++m)
    5427:       if (glabels[m] == glabels[gl]) goto next_label;
    5428:     PetscCall(DMConvert(dm, DMPLEX, &plex));
    5429:     PetscCall(DMPlexLabelComplete(plex, glabels[gl]));
    5430:     PetscCall(DMDestroy(&plex));
    5431:     ++gl;
    5432:   next_label:
    5433:     continue;
    5434:   }
    5435:   PetscCall(PetscFree2(recvNames, glabels));
    5436:   PetscFunctionReturn(PETSC_SUCCESS);
    5437: }

    5439: static PetscErrorCode DMDSEnlarge_Static(DM dm, PetscInt NdsNew)
    5440: {
    5441:   DMSpace *tmpd;
    5442:   PetscInt Nds = dm->Nds, s;

    5444:   PetscFunctionBegin;
    5445:   if (Nds >= NdsNew) PetscFunctionReturn(PETSC_SUCCESS);
    5446:   PetscCall(PetscMalloc1(NdsNew, &tmpd));
    5447:   for (s = 0; s < Nds; ++s) tmpd[s] = dm->probs[s];
    5448:   for (s = Nds; s < NdsNew; ++s) {
    5449:     tmpd[s].ds     = NULL;
    5450:     tmpd[s].label  = NULL;
    5451:     tmpd[s].fields = NULL;
    5452:   }
    5453:   PetscCall(PetscFree(dm->probs));
    5454:   dm->Nds   = NdsNew;
    5455:   dm->probs = tmpd;
    5456:   PetscFunctionReturn(PETSC_SUCCESS);
    5457: }

    5459: /*@
    5460:   DMGetNumDS - Get the number of discrete systems in the `DM`

    5462:   Not Collective

    5464:   Input Parameter:
    5465: . dm - The `DM`

    5467:   Output Parameter:
    5468: . Nds - The number of `PetscDS` objects

    5470:   Level: intermediate

    5472: .seealso: [](ch_dmbase), `DM`, `DMGetDS()`, `DMGetCellDS()`
    5473: @*/
    5474: PetscErrorCode DMGetNumDS(DM dm, PetscInt *Nds)
    5475: {
    5476:   PetscFunctionBegin;
    5478:   PetscAssertPointer(Nds, 2);
    5479:   *Nds = dm->Nds;
    5480:   PetscFunctionReturn(PETSC_SUCCESS);
    5481: }

    5483: /*@
    5484:   DMClearDS - Remove all discrete systems from the `DM`

    5486:   Logically Collective

    5488:   Input Parameter:
    5489: . dm - The `DM`

    5491:   Level: intermediate

    5493: .seealso: [](ch_dmbase), `DM`, `DMGetNumDS()`, `DMGetDS()`, `DMSetField()`
    5494: @*/
    5495: PetscErrorCode DMClearDS(DM dm)
    5496: {
    5497:   PetscInt s;

    5499:   PetscFunctionBegin;
    5501:   for (s = 0; s < dm->Nds; ++s) {
    5502:     PetscCall(PetscDSDestroy(&dm->probs[s].ds));
    5503:     PetscCall(PetscDSDestroy(&dm->probs[s].dsIn));
    5504:     PetscCall(DMLabelDestroy(&dm->probs[s].label));
    5505:     PetscCall(ISDestroy(&dm->probs[s].fields));
    5506:   }
    5507:   PetscCall(PetscFree(dm->probs));
    5508:   dm->probs = NULL;
    5509:   dm->Nds   = 0;
    5510:   PetscFunctionReturn(PETSC_SUCCESS);
    5511: }

    5513: /*@
    5514:   DMGetDS - Get the default `PetscDS`

    5516:   Not Collective

    5518:   Input Parameter:
    5519: . dm - The `DM`

    5521:   Output Parameter:
    5522: . ds - The default `PetscDS`

    5524:   Level: intermediate

    5526:   Note:
    5527:   The `ds` is owned by the `dm` and should not be destroyed directly.

    5529: .seealso: [](ch_dmbase), `DM`, `DMGetCellDS()`, `DMGetRegionDS()`
    5530: @*/
    5531: PetscErrorCode DMGetDS(DM dm, PetscDS *ds)
    5532: {
    5533:   PetscFunctionBeginHot;
    5535:   PetscAssertPointer(ds, 2);
    5536:   PetscCheck(dm->Nds > 0, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Need to call DMCreateDS() before calling DMGetDS()");
    5537:   *ds = dm->probs[0].ds;
    5538:   PetscFunctionReturn(PETSC_SUCCESS);
    5539: }

    5541: /*@
    5542:   DMGetCellDS - Get the `PetscDS` defined on a given cell

    5544:   Not Collective

    5546:   Input Parameters:
    5547: + dm    - The `DM`
    5548: - point - Cell for the `PetscDS`

    5550:   Output Parameters:
    5551: + ds   - The `PetscDS` defined on the given cell
    5552: - dsIn - The `PetscDS` for input on the given cell, or NULL if the same ds

    5554:   Level: developer

    5556: .seealso: [](ch_dmbase), `DM`, `DMGetDS()`, `DMSetRegionDS()`
    5557: @*/
    5558: PetscErrorCode DMGetCellDS(DM dm, PetscInt point, PetscDS *ds, PetscDS *dsIn)
    5559: {
    5560:   PetscDS  dsDef = NULL;
    5561:   PetscInt s;

    5563:   PetscFunctionBeginHot;
    5565:   if (ds) PetscAssertPointer(ds, 3);
    5566:   if (dsIn) PetscAssertPointer(dsIn, 4);
    5567:   PetscCheck(point >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Mesh point cannot be negative: %" PetscInt_FMT, point);
    5568:   if (ds) *ds = NULL;
    5569:   if (dsIn) *dsIn = NULL;
    5570:   for (s = 0; s < dm->Nds; ++s) {
    5571:     PetscInt val;

    5573:     if (!dm->probs[s].label) {
    5574:       dsDef = dm->probs[s].ds;
    5575:     } else {
    5576:       PetscCall(DMLabelGetValue(dm->probs[s].label, point, &val));
    5577:       if (val >= 0) {
    5578:         if (ds) *ds = dm->probs[s].ds;
    5579:         if (dsIn) *dsIn = dm->probs[s].dsIn;
    5580:         break;
    5581:       }
    5582:     }
    5583:   }
    5584:   if (ds && !*ds) *ds = dsDef;
    5585:   PetscFunctionReturn(PETSC_SUCCESS);
    5586: }

    5588: /*@
    5589:   DMGetRegionDS - Get the `PetscDS` for a given mesh region, defined by a `DMLabel`

    5591:   Not Collective

    5593:   Input Parameters:
    5594: + dm    - The `DM`
    5595: - label - The `DMLabel` defining the mesh region, or `NULL` for the entire mesh

    5597:   Output Parameters:
    5598: + fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL`
    5599: . ds     - The `PetscDS` defined on the given region, or `NULL`
    5600: - dsIn   - The `PetscDS` for input in the given region, or `NULL`

    5602:   Level: advanced

    5604:   Note:
    5605:   If a non-`NULL` label is given, but there is no `PetscDS` on that specific label,
    5606:   the `PetscDS` for the full domain (if present) is returned. Returns with
    5607:   fields = `NULL` and ds = `NULL` if there is no `PetscDS` for the full domain.

    5609: .seealso: [](ch_dmbase), `DM`, `DMGetRegionNumDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5610: @*/
    5611: PetscErrorCode DMGetRegionDS(DM dm, DMLabel label, IS *fields, PetscDS *ds, PetscDS *dsIn)
    5612: {
    5613:   PetscInt Nds = dm->Nds, s;

    5615:   PetscFunctionBegin;
    5618:   if (fields) {
    5619:     PetscAssertPointer(fields, 3);
    5620:     *fields = NULL;
    5621:   }
    5622:   if (ds) {
    5623:     PetscAssertPointer(ds, 4);
    5624:     *ds = NULL;
    5625:   }
    5626:   if (dsIn) {
    5627:     PetscAssertPointer(dsIn, 5);
    5628:     *dsIn = NULL;
    5629:   }
    5630:   for (s = 0; s < Nds; ++s) {
    5631:     if (dm->probs[s].label == label || !dm->probs[s].label) {
    5632:       if (fields) *fields = dm->probs[s].fields;
    5633:       if (ds) *ds = dm->probs[s].ds;
    5634:       if (dsIn) *dsIn = dm->probs[s].dsIn;
    5635:       if (dm->probs[s].label) PetscFunctionReturn(PETSC_SUCCESS);
    5636:     }
    5637:   }
    5638:   PetscFunctionReturn(PETSC_SUCCESS);
    5639: }

    5641: /*@
    5642:   DMSetRegionDS - Set the `PetscDS` for a given mesh region, defined by a `DMLabel`

    5644:   Collective

    5646:   Input Parameters:
    5647: + dm     - The `DM`
    5648: . label  - The `DMLabel` defining the mesh region, or `NULL` for the entire mesh
    5649: . fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL` for all fields
    5650: . ds     - The `PetscDS` defined on the given region
    5651: - dsIn   - The `PetscDS` for input on the given cell, or `NULL` if it is the same `PetscDS`

    5653:   Level: advanced

    5655:   Note:
    5656:   If the label has a `PetscDS` defined, it will be replaced. Otherwise, it will be added to the `DM`. If the `PetscDS` is replaced,
    5657:   the fields argument is ignored.

    5659: .seealso: [](ch_dmbase), `DM`, `DMGetRegionDS()`, `DMSetRegionNumDS()`, `DMGetDS()`, `DMGetCellDS()`
    5660: @*/
    5661: PetscErrorCode DMSetRegionDS(DM dm, DMLabel label, IS fields, PetscDS ds, PetscDS dsIn)
    5662: {
    5663:   PetscInt Nds = dm->Nds, s;

    5665:   PetscFunctionBegin;
    5671:   for (s = 0; s < Nds; ++s) {
    5672:     if (dm->probs[s].label == label) {
    5673:       PetscCall(PetscDSDestroy(&dm->probs[s].ds));
    5674:       PetscCall(PetscDSDestroy(&dm->probs[s].dsIn));
    5675:       dm->probs[s].ds   = ds;
    5676:       dm->probs[s].dsIn = dsIn;
    5677:       PetscFunctionReturn(PETSC_SUCCESS);
    5678:     }
    5679:   }
    5680:   PetscCall(DMDSEnlarge_Static(dm, Nds + 1));
    5681:   PetscCall(PetscObjectReference((PetscObject)label));
    5682:   PetscCall(PetscObjectReference((PetscObject)fields));
    5683:   PetscCall(PetscObjectReference((PetscObject)ds));
    5684:   PetscCall(PetscObjectReference((PetscObject)dsIn));
    5685:   if (!label) {
    5686:     /* Put the NULL label at the front, so it is returned as the default */
    5687:     for (s = Nds - 1; s >= 0; --s) dm->probs[s + 1] = dm->probs[s];
    5688:     Nds = 0;
    5689:   }
    5690:   dm->probs[Nds].label  = label;
    5691:   dm->probs[Nds].fields = fields;
    5692:   dm->probs[Nds].ds     = ds;
    5693:   dm->probs[Nds].dsIn   = dsIn;
    5694:   PetscFunctionReturn(PETSC_SUCCESS);
    5695: }

    5697: /*@
    5698:   DMGetRegionNumDS - Get the `PetscDS` for a given mesh region, defined by the region number

    5700:   Not Collective

    5702:   Input Parameters:
    5703: + dm  - The `DM`
    5704: - num - The region number, in [0, Nds)

    5706:   Output Parameters:
    5707: + label  - The region label, or `NULL`
    5708: . fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL`
    5709: . ds     - The `PetscDS` defined on the given region, or `NULL`
    5710: - dsIn   - The `PetscDS` for input in the given region, or `NULL`

    5712:   Level: advanced

    5714: .seealso: [](ch_dmbase), `DM`, `DMGetRegionDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5715: @*/
    5716: PetscErrorCode DMGetRegionNumDS(DM dm, PetscInt num, DMLabel *label, IS *fields, PetscDS *ds, PetscDS *dsIn)
    5717: {
    5718:   PetscInt Nds;

    5720:   PetscFunctionBegin;
    5722:   PetscCall(DMGetNumDS(dm, &Nds));
    5723:   PetscCheck((num >= 0) && (num < Nds), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Region number %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", num, Nds);
    5724:   if (label) {
    5725:     PetscAssertPointer(label, 3);
    5726:     *label = dm->probs[num].label;
    5727:   }
    5728:   if (fields) {
    5729:     PetscAssertPointer(fields, 4);
    5730:     *fields = dm->probs[num].fields;
    5731:   }
    5732:   if (ds) {
    5733:     PetscAssertPointer(ds, 5);
    5734:     *ds = dm->probs[num].ds;
    5735:   }
    5736:   if (dsIn) {
    5737:     PetscAssertPointer(dsIn, 6);
    5738:     *dsIn = dm->probs[num].dsIn;
    5739:   }
    5740:   PetscFunctionReturn(PETSC_SUCCESS);
    5741: }

    5743: /*@
    5744:   DMSetRegionNumDS - Set the `PetscDS` for a given mesh region, defined by the region number

    5746:   Not Collective

    5748:   Input Parameters:
    5749: + dm     - The `DM`
    5750: . num    - The region number, in [0, Nds)
    5751: . label  - The region label, or `NULL`
    5752: . fields - The `IS` containing the `DM` field numbers for the fields in this `PetscDS`, or `NULL` to prevent setting
    5753: . ds     - The `PetscDS` defined on the given region, or `NULL` to prevent setting
    5754: - dsIn   - The `PetscDS` for input on the given cell, or `NULL` if it is the same `PetscDS`

    5756:   Level: advanced

    5758: .seealso: [](ch_dmbase), `DM`, `DMGetRegionDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5759: @*/
    5760: PetscErrorCode DMSetRegionNumDS(DM dm, PetscInt num, DMLabel label, IS fields, PetscDS ds, PetscDS dsIn)
    5761: {
    5762:   PetscInt Nds;

    5764:   PetscFunctionBegin;
    5767:   PetscCall(DMGetNumDS(dm, &Nds));
    5768:   PetscCheck((num >= 0) && (num < Nds), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Region number %" PetscInt_FMT " is not in [0, %" PetscInt_FMT ")", num, Nds);
    5769:   PetscCall(PetscObjectReference((PetscObject)label));
    5770:   PetscCall(DMLabelDestroy(&dm->probs[num].label));
    5771:   dm->probs[num].label = label;
    5772:   if (fields) {
    5774:     PetscCall(PetscObjectReference((PetscObject)fields));
    5775:     PetscCall(ISDestroy(&dm->probs[num].fields));
    5776:     dm->probs[num].fields = fields;
    5777:   }
    5778:   if (ds) {
    5780:     PetscCall(PetscObjectReference((PetscObject)ds));
    5781:     PetscCall(PetscDSDestroy(&dm->probs[num].ds));
    5782:     dm->probs[num].ds = ds;
    5783:   }
    5784:   if (dsIn) {
    5786:     PetscCall(PetscObjectReference((PetscObject)dsIn));
    5787:     PetscCall(PetscDSDestroy(&dm->probs[num].dsIn));
    5788:     dm->probs[num].dsIn = dsIn;
    5789:   }
    5790:   PetscFunctionReturn(PETSC_SUCCESS);
    5791: }

    5793: /*@
    5794:   DMFindRegionNum - Find the region number for a given `PetscDS`, or -1 if it is not found.

    5796:   Not Collective

    5798:   Input Parameters:
    5799: + dm - The `DM`
    5800: - ds - The `PetscDS` defined on the given region

    5802:   Output Parameter:
    5803: . num - The region number, in [0, Nds), or -1 if not found

    5805:   Level: advanced

    5807: .seealso: [](ch_dmbase), `DM`, `DMGetRegionNumDS()`, `DMGetRegionDS()`, `DMSetRegionDS()`, `DMGetDS()`, `DMGetCellDS()`
    5808: @*/
    5809: PetscErrorCode DMFindRegionNum(DM dm, PetscDS ds, PetscInt *num)
    5810: {
    5811:   PetscInt Nds, n;

    5813:   PetscFunctionBegin;
    5816:   PetscAssertPointer(num, 3);
    5817:   PetscCall(DMGetNumDS(dm, &Nds));
    5818:   for (n = 0; n < Nds; ++n)
    5819:     if (ds == dm->probs[n].ds) break;
    5820:   if (n >= Nds) *num = -1;
    5821:   else *num = n;
    5822:   PetscFunctionReturn(PETSC_SUCCESS);
    5823: }

    5825: /*@
    5826:   DMCreateFEDefault - Create a `PetscFE` based on the celltype for the mesh

    5828:   Not Collective

    5830:   Input Parameters:
    5831: + dm     - The `DM`
    5832: . Nc     - The number of components for the field
    5833: . prefix - The options prefix for the output `PetscFE`, or `NULL`
    5834: - qorder - The quadrature order or `PETSC_DETERMINE` to use `PetscSpace` polynomial degree

    5836:   Output Parameter:
    5837: . fem - The `PetscFE`

    5839:   Level: intermediate

    5841:   Note:
    5842:   This is a convenience method that just calls `PetscFECreateByCell()` underneath.

    5844: .seealso: [](ch_dmbase), `DM`, `PetscFECreateByCell()`, `DMAddField()`, `DMCreateDS()`, `DMGetCellDS()`, `DMGetRegionDS()`
    5845: @*/
    5846: PetscErrorCode DMCreateFEDefault(DM dm, PetscInt Nc, const char prefix[], PetscInt qorder, PetscFE *fem)
    5847: {
    5848:   DMPolytopeType ct;
    5849:   PetscInt       dim, cStart;

    5851:   PetscFunctionBegin;
    5854:   if (prefix) PetscAssertPointer(prefix, 3);
    5856:   PetscAssertPointer(fem, 5);
    5857:   PetscCall(DMGetDimension(dm, &dim));
    5858:   PetscCall(DMPlexGetHeightStratum(dm, 0, &cStart, NULL));
    5859:   PetscCall(DMPlexGetCellType(dm, cStart, &ct));
    5860:   PetscCall(PetscFECreateByCell(PETSC_COMM_SELF, dim, Nc, ct, prefix, qorder, fem));
    5861:   PetscFunctionReturn(PETSC_SUCCESS);
    5862: }

    5864: /*@
    5865:   DMCreateDS - Create the discrete systems for the `DM` based upon the fields added to the `DM`

    5867:   Collective

    5869:   Input Parameter:
    5870: . dm - The `DM`

    5872:   Options Database Key:
    5873: . -dm_petscds_view - View all the `PetscDS` objects in this `DM`

    5875:   Level: intermediate

    5877:   Developer Note:
    5878:   The name of this function is wrong. Create functions always return the created object as one of the arguments.

    5880: .seealso: [](ch_dmbase), `DM`, `DMSetField`, `DMAddField()`, `DMGetDS()`, `DMGetCellDS()`, `DMGetRegionDS()`, `DMSetRegionDS()`
    5881: @*/
    5882: PetscErrorCode DMCreateDS(DM dm)
    5883: {
    5884:   MPI_Comm  comm;
    5885:   PetscDS   dsDef;
    5886:   DMLabel  *labelSet;
    5887:   PetscInt  dE, Nf = dm->Nf, f, s, Nl, l, Ndef, k;
    5888:   PetscBool doSetup = PETSC_TRUE, flg;

    5890:   PetscFunctionBegin;
    5892:   if (!dm->fields) PetscFunctionReturn(PETSC_SUCCESS);
    5893:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
    5894:   PetscCall(DMGetCoordinateDim(dm, &dE));
    5895:   /* Determine how many regions we have */
    5896:   PetscCall(PetscMalloc1(Nf, &labelSet));
    5897:   Nl   = 0;
    5898:   Ndef = 0;
    5899:   for (f = 0; f < Nf; ++f) {
    5900:     DMLabel  label = dm->fields[f].label;
    5901:     PetscInt l;

    5903: #ifdef PETSC_HAVE_LIBCEED
    5904:     /* Move CEED context to discretizations */
    5905:     {
    5906:       PetscClassId id;

    5908:       PetscCall(PetscObjectGetClassId(dm->fields[f].disc, &id));
    5909:       if (id == PETSCFE_CLASSID) {
    5910:         Ceed ceed;

    5912:         PetscCall(DMGetCeed(dm, &ceed));
    5913:         PetscCall(PetscFESetCeed((PetscFE)dm->fields[f].disc, ceed));
    5914:       }
    5915:     }
    5916: #endif
    5917:     if (!label) {
    5918:       ++Ndef;
    5919:       continue;
    5920:     }
    5921:     for (l = 0; l < Nl; ++l)
    5922:       if (label == labelSet[l]) break;
    5923:     if (l < Nl) continue;
    5924:     labelSet[Nl++] = label;
    5925:   }
    5926:   /* Create default DS if there are no labels to intersect with */
    5927:   PetscCall(DMGetRegionDS(dm, NULL, NULL, &dsDef, NULL));
    5928:   if (!dsDef && Ndef && !Nl) {
    5929:     IS        fields;
    5930:     PetscInt *fld, nf;

    5932:     for (f = 0, nf = 0; f < Nf; ++f)
    5933:       if (!dm->fields[f].label) ++nf;
    5934:     PetscCheck(nf, comm, PETSC_ERR_PLIB, "All fields have labels, but we are trying to create a default DS");
    5935:     PetscCall(PetscMalloc1(nf, &fld));
    5936:     for (f = 0, nf = 0; f < Nf; ++f)
    5937:       if (!dm->fields[f].label) fld[nf++] = f;
    5938:     PetscCall(ISCreate(PETSC_COMM_SELF, &fields));
    5939:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)fields, "dm_fields_"));
    5940:     PetscCall(ISSetType(fields, ISGENERAL));
    5941:     PetscCall(ISGeneralSetIndices(fields, nf, fld, PETSC_OWN_POINTER));

    5943:     PetscCall(PetscDSCreate(PETSC_COMM_SELF, &dsDef));
    5944:     PetscCall(DMSetRegionDS(dm, NULL, fields, dsDef, NULL));
    5945:     PetscCall(PetscDSDestroy(&dsDef));
    5946:     PetscCall(ISDestroy(&fields));
    5947:   }
    5948:   PetscCall(DMGetRegionDS(dm, NULL, NULL, &dsDef, NULL));
    5949:   if (dsDef) PetscCall(PetscDSSetCoordinateDimension(dsDef, dE));
    5950:   /* Intersect labels with default fields */
    5951:   if (Ndef && Nl) {
    5952:     DM              plex;
    5953:     DMLabel         cellLabel;
    5954:     IS              fieldIS, allcellIS, defcellIS = NULL;
    5955:     PetscInt       *fields;
    5956:     const PetscInt *cells;
    5957:     PetscInt        depth, nf = 0, n, c;

    5959:     PetscCall(DMConvert(dm, DMPLEX, &plex));
    5960:     PetscCall(DMPlexGetDepth(plex, &depth));
    5961:     PetscCall(DMGetStratumIS(plex, "dim", depth, &allcellIS));
    5962:     if (!allcellIS) PetscCall(DMGetStratumIS(plex, "depth", depth, &allcellIS));
    5963:     /* TODO This looks like it only works for one label */
    5964:     for (l = 0; l < Nl; ++l) {
    5965:       DMLabel label = labelSet[l];
    5966:       IS      pointIS;

    5968:       PetscCall(ISDestroy(&defcellIS));
    5969:       PetscCall(DMLabelGetStratumIS(label, 1, &pointIS));
    5970:       PetscCall(ISDifference(allcellIS, pointIS, &defcellIS));
    5971:       PetscCall(ISDestroy(&pointIS));
    5972:     }
    5973:     PetscCall(ISDestroy(&allcellIS));

    5975:     PetscCall(DMLabelCreate(PETSC_COMM_SELF, "defaultCells", &cellLabel));
    5976:     PetscCall(ISGetLocalSize(defcellIS, &n));
    5977:     PetscCall(ISGetIndices(defcellIS, &cells));
    5978:     for (c = 0; c < n; ++c) PetscCall(DMLabelSetValue(cellLabel, cells[c], 1));
    5979:     PetscCall(ISRestoreIndices(defcellIS, &cells));
    5980:     PetscCall(ISDestroy(&defcellIS));
    5981:     PetscCall(DMPlexLabelComplete(plex, cellLabel));

    5983:     PetscCall(PetscMalloc1(Ndef, &fields));
    5984:     for (f = 0; f < Nf; ++f)
    5985:       if (!dm->fields[f].label) fields[nf++] = f;
    5986:     PetscCall(ISCreate(PETSC_COMM_SELF, &fieldIS));
    5987:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)fieldIS, "dm_fields_"));
    5988:     PetscCall(ISSetType(fieldIS, ISGENERAL));
    5989:     PetscCall(ISGeneralSetIndices(fieldIS, nf, fields, PETSC_OWN_POINTER));

    5991:     PetscCall(PetscDSCreate(PETSC_COMM_SELF, &dsDef));
    5992:     PetscCall(DMSetRegionDS(dm, cellLabel, fieldIS, dsDef, NULL));
    5993:     PetscCall(PetscDSSetCoordinateDimension(dsDef, dE));
    5994:     PetscCall(DMLabelDestroy(&cellLabel));
    5995:     PetscCall(PetscDSDestroy(&dsDef));
    5996:     PetscCall(ISDestroy(&fieldIS));
    5997:     PetscCall(DMDestroy(&plex));
    5998:   }
    5999:   /* Create label DSes
    6000:      - WE ONLY SUPPORT IDENTICAL OR DISJOINT LABELS
    6001:   */
    6002:   /* TODO Should check that labels are disjoint */
    6003:   for (l = 0; l < Nl; ++l) {
    6004:     DMLabel   label = labelSet[l];
    6005:     PetscDS   ds, dsIn = NULL;
    6006:     IS        fields;
    6007:     PetscInt *fld, nf;

    6009:     PetscCall(PetscDSCreate(PETSC_COMM_SELF, &ds));
    6010:     for (f = 0, nf = 0; f < Nf; ++f)
    6011:       if (label == dm->fields[f].label || !dm->fields[f].label) ++nf;
    6012:     PetscCall(PetscMalloc1(nf, &fld));
    6013:     for (f = 0, nf = 0; f < Nf; ++f)
    6014:       if (label == dm->fields[f].label || !dm->fields[f].label) fld[nf++] = f;
    6015:     PetscCall(ISCreate(PETSC_COMM_SELF, &fields));
    6016:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)fields, "dm_fields_"));
    6017:     PetscCall(ISSetType(fields, ISGENERAL));
    6018:     PetscCall(ISGeneralSetIndices(fields, nf, fld, PETSC_OWN_POINTER));
    6019:     PetscCall(PetscDSSetCoordinateDimension(ds, dE));
    6020:     {
    6021:       DMPolytopeType ct;
    6022:       PetscInt       lStart, lEnd;
    6023:       PetscBool      isCohesiveLocal = PETSC_FALSE, isCohesive;

    6025:       PetscCall(DMLabelGetBounds(label, &lStart, &lEnd));
    6026:       if (lStart >= 0) {
    6027:         PetscCall(DMPlexGetCellType(dm, lStart, &ct));
    6028:         switch (ct) {
    6029:         case DM_POLYTOPE_POINT_PRISM_TENSOR:
    6030:         case DM_POLYTOPE_SEG_PRISM_TENSOR:
    6031:         case DM_POLYTOPE_TRI_PRISM_TENSOR:
    6032:         case DM_POLYTOPE_QUAD_PRISM_TENSOR:
    6033:           isCohesiveLocal = PETSC_TRUE;
    6034:           break;
    6035:         default:
    6036:           break;
    6037:         }
    6038:       }
    6039:       PetscCallMPI(MPIU_Allreduce(&isCohesiveLocal, &isCohesive, 1, MPIU_BOOL, MPI_LOR, comm));
    6040:       if (isCohesive) {
    6041:         PetscCall(PetscDSCreate(PETSC_COMM_SELF, &dsIn));
    6042:         PetscCall(PetscDSSetCoordinateDimension(dsIn, dE));
    6043:       }
    6044:       for (f = 0, nf = 0; f < Nf; ++f) {
    6045:         if (label == dm->fields[f].label || !dm->fields[f].label) {
    6046:           if (label == dm->fields[f].label) {
    6047:             PetscCall(PetscDSSetDiscretization(ds, nf, NULL));
    6048:             PetscCall(PetscDSSetCohesive(ds, nf, isCohesive));
    6049:             if (dsIn) {
    6050:               PetscCall(PetscDSSetDiscretization(dsIn, nf, NULL));
    6051:               PetscCall(PetscDSSetCohesive(dsIn, nf, isCohesive));
    6052:             }
    6053:           }
    6054:           ++nf;
    6055:         }
    6056:       }
    6057:     }
    6058:     PetscCall(DMSetRegionDS(dm, label, fields, ds, dsIn));
    6059:     PetscCall(ISDestroy(&fields));
    6060:     PetscCall(PetscDSDestroy(&ds));
    6061:     PetscCall(PetscDSDestroy(&dsIn));
    6062:   }
    6063:   PetscCall(PetscFree(labelSet));
    6064:   /* Set fields in DSes */
    6065:   for (s = 0; s < dm->Nds; ++s) {
    6066:     PetscDS         ds     = dm->probs[s].ds;
    6067:     PetscDS         dsIn   = dm->probs[s].dsIn;
    6068:     IS              fields = dm->probs[s].fields;
    6069:     const PetscInt *fld;
    6070:     PetscInt        nf, dsnf;
    6071:     PetscBool       isCohesive;

    6073:     PetscCall(PetscDSGetNumFields(ds, &dsnf));
    6074:     PetscCall(PetscDSIsCohesive(ds, &isCohesive));
    6075:     PetscCall(ISGetLocalSize(fields, &nf));
    6076:     PetscCall(ISGetIndices(fields, &fld));
    6077:     for (f = 0; f < nf; ++f) {
    6078:       PetscObject  disc = dm->fields[fld[f]].disc;
    6079:       PetscBool    isCohesiveField;
    6080:       PetscClassId id;

    6082:       /* Handle DS with no fields */
    6083:       if (dsnf) PetscCall(PetscDSGetCohesive(ds, f, &isCohesiveField));
    6084:       /* If this is a cohesive cell, then regular fields need the lower dimensional discretization */
    6085:       if (isCohesive) {
    6086:         if (!isCohesiveField) {
    6087:           PetscObject bdDisc;

    6089:           PetscCall(PetscFEGetHeightSubspace((PetscFE)disc, 1, (PetscFE *)&bdDisc));
    6090:           PetscCall(PetscDSSetDiscretization(ds, f, bdDisc));
    6091:           PetscCall(PetscDSSetDiscretization(dsIn, f, disc));
    6092:         } else {
    6093:           PetscCall(PetscDSSetDiscretization(ds, f, disc));
    6094:           PetscCall(PetscDSSetDiscretization(dsIn, f, disc));
    6095:         }
    6096:       } else {
    6097:         PetscCall(PetscDSSetDiscretization(ds, f, disc));
    6098:       }
    6099:       /* We allow people to have placeholder fields and construct the Section by hand */
    6100:       PetscCall(PetscObjectGetClassId(disc, &id));
    6101:       if ((id != PETSCFE_CLASSID) && (id != PETSCFV_CLASSID)) doSetup = PETSC_FALSE;
    6102:     }
    6103:     PetscCall(ISRestoreIndices(fields, &fld));
    6104:   }
    6105:   /* Allow k-jet tabulation */
    6106:   PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)dm)->prefix, "-dm_ds_jet_degree", &k, &flg));
    6107:   if (flg) {
    6108:     for (s = 0; s < dm->Nds; ++s) {
    6109:       PetscDS  ds   = dm->probs[s].ds;
    6110:       PetscDS  dsIn = dm->probs[s].dsIn;
    6111:       PetscInt Nf, f;

    6113:       PetscCall(PetscDSGetNumFields(ds, &Nf));
    6114:       for (f = 0; f < Nf; ++f) {
    6115:         PetscCall(PetscDSSetJetDegree(ds, f, k));
    6116:         if (dsIn) PetscCall(PetscDSSetJetDegree(dsIn, f, k));
    6117:       }
    6118:     }
    6119:   }
    6120:   /* Setup DSes */
    6121:   if (doSetup) {
    6122:     for (s = 0; s < dm->Nds; ++s) {
    6123:       if (dm->setfromoptionscalled) {
    6124:         PetscCall(PetscDSSetFromOptions(dm->probs[s].ds));
    6125:         if (dm->probs[s].dsIn) PetscCall(PetscDSSetFromOptions(dm->probs[s].dsIn));
    6126:       }
    6127:       PetscCall(PetscDSSetUp(dm->probs[s].ds));
    6128:       if (dm->probs[s].dsIn) PetscCall(PetscDSSetUp(dm->probs[s].dsIn));
    6129:     }
    6130:   }
    6131:   PetscFunctionReturn(PETSC_SUCCESS);
    6132: }

    6134: /*@
    6135:   DMUseTensorOrder - Use a tensor product closure ordering for the default section

    6137:   Input Parameters:
    6138: + dm     - The DM
    6139: - tensor - Flag for tensor order

    6141:   Level: developer

    6143: .seealso: `DMPlexSetClosurePermutationTensor()`, `PetscSectionResetClosurePermutation()`
    6144: @*/
    6145: PetscErrorCode DMUseTensorOrder(DM dm, PetscBool tensor)
    6146: {
    6147:   PetscInt  Nf;
    6148:   PetscBool reorder = PETSC_TRUE, isPlex;

    6150:   PetscFunctionBegin;
    6151:   PetscCall(PetscObjectTypeCompare((PetscObject)dm, DMPLEX, &isPlex));
    6152:   PetscCall(DMGetNumFields(dm, &Nf));
    6153:   for (PetscInt f = 0; f < Nf; ++f) {
    6154:     PetscObject  obj;
    6155:     PetscClassId id;

    6157:     PetscCall(DMGetField(dm, f, NULL, &obj));
    6158:     PetscCall(PetscObjectGetClassId(obj, &id));
    6159:     if (id == PETSCFE_CLASSID) {
    6160:       PetscSpace sp;
    6161:       PetscBool  tensor;

    6163:       PetscCall(PetscFEGetBasisSpace((PetscFE)obj, &sp));
    6164:       PetscCall(PetscSpacePolynomialGetTensor(sp, &tensor));
    6165:       reorder = reorder && tensor ? PETSC_TRUE : PETSC_FALSE;
    6166:     } else reorder = PETSC_FALSE;
    6167:   }
    6168:   if (tensor) {
    6169:     if (reorder && isPlex) PetscCall(DMPlexSetClosurePermutationTensor(dm, PETSC_DETERMINE, NULL));
    6170:   } else {
    6171:     PetscSection s;

    6173:     PetscCall(DMGetLocalSection(dm, &s));
    6174:     if (s) PetscCall(PetscSectionResetClosurePermutation(s));
    6175:   }
    6176:   PetscFunctionReturn(PETSC_SUCCESS);
    6177: }

    6179: /*@
    6180:   DMComputeExactSolution - Compute the exact solution for a given `DM`, using the `PetscDS` information.

    6182:   Collective

    6184:   Input Parameters:
    6185: + dm   - The `DM`
    6186: - time - The time

    6188:   Output Parameters:
    6189: + u   - The vector will be filled with exact solution values, or `NULL`
    6190: - u_t - The vector will be filled with the time derivative of exact solution values, or `NULL`

    6192:   Level: developer

    6194:   Note:
    6195:   The user must call `PetscDSSetExactSolution()` before using this routine

    6197: .seealso: [](ch_dmbase), `DM`, `PetscDSSetExactSolution()`
    6198: @*/
    6199: PetscErrorCode DMComputeExactSolution(DM dm, PetscReal time, Vec u, Vec u_t)
    6200: {
    6201:   PetscErrorCode (**exacts)(PetscInt, PetscReal, const PetscReal x[], PetscInt, PetscScalar *u, void *ctx);
    6202:   void   **ectxs;
    6203:   Vec      locu, locu_t;
    6204:   PetscInt Nf, Nds, s;

    6206:   PetscFunctionBegin;
    6208:   if (u) {
    6210:     PetscCall(DMGetLocalVector(dm, &locu));
    6211:     PetscCall(VecSet(locu, 0.));
    6212:   }
    6213:   if (u_t) {
    6215:     PetscCall(DMGetLocalVector(dm, &locu_t));
    6216:     PetscCall(VecSet(locu_t, 0.));
    6217:   }
    6218:   PetscCall(DMGetNumFields(dm, &Nf));
    6219:   PetscCall(PetscMalloc2(Nf, &exacts, Nf, &ectxs));
    6220:   PetscCall(DMGetNumDS(dm, &Nds));
    6221:   for (s = 0; s < Nds; ++s) {
    6222:     PetscDS         ds;
    6223:     DMLabel         label;
    6224:     IS              fieldIS;
    6225:     const PetscInt *fields, id = 1;
    6226:     PetscInt        dsNf, f;

    6228:     PetscCall(DMGetRegionNumDS(dm, s, &label, &fieldIS, &ds, NULL));
    6229:     PetscCall(PetscDSGetNumFields(ds, &dsNf));
    6230:     PetscCall(ISGetIndices(fieldIS, &fields));
    6231:     PetscCall(PetscArrayzero(exacts, Nf));
    6232:     PetscCall(PetscArrayzero(ectxs, Nf));
    6233:     if (u) {
    6234:       for (f = 0; f < dsNf; ++f) PetscCall(PetscDSGetExactSolution(ds, fields[f], &exacts[fields[f]], &ectxs[fields[f]]));
    6235:       if (label) PetscCall(DMProjectFunctionLabelLocal(dm, time, label, 1, &id, 0, NULL, exacts, ectxs, INSERT_ALL_VALUES, locu));
    6236:       else PetscCall(DMProjectFunctionLocal(dm, time, exacts, ectxs, INSERT_ALL_VALUES, locu));
    6237:     }
    6238:     if (u_t) {
    6239:       PetscCall(PetscArrayzero(exacts, Nf));
    6240:       PetscCall(PetscArrayzero(ectxs, Nf));
    6241:       for (f = 0; f < dsNf; ++f) PetscCall(PetscDSGetExactSolutionTimeDerivative(ds, fields[f], &exacts[fields[f]], &ectxs[fields[f]]));
    6242:       if (label) PetscCall(DMProjectFunctionLabelLocal(dm, time, label, 1, &id, 0, NULL, exacts, ectxs, INSERT_ALL_VALUES, locu_t));
    6243:       else PetscCall(DMProjectFunctionLocal(dm, time, exacts, ectxs, INSERT_ALL_VALUES, locu_t));
    6244:     }
    6245:     PetscCall(ISRestoreIndices(fieldIS, &fields));
    6246:   }
    6247:   if (u) {
    6248:     PetscCall(PetscObjectSetName((PetscObject)u, "Exact Solution"));
    6249:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)u, "exact_"));
    6250:   }
    6251:   if (u_t) {
    6252:     PetscCall(PetscObjectSetName((PetscObject)u, "Exact Solution Time Derivative"));
    6253:     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)u_t, "exact_t_"));
    6254:   }
    6255:   PetscCall(PetscFree2(exacts, ectxs));
    6256:   if (u) {
    6257:     PetscCall(DMLocalToGlobalBegin(dm, locu, INSERT_ALL_VALUES, u));
    6258:     PetscCall(DMLocalToGlobalEnd(dm, locu, INSERT_ALL_VALUES, u));
    6259:     PetscCall(DMRestoreLocalVector(dm, &locu));
    6260:   }
    6261:   if (u_t) {
    6262:     PetscCall(DMLocalToGlobalBegin(dm, locu_t, INSERT_ALL_VALUES, u_t));
    6263:     PetscCall(DMLocalToGlobalEnd(dm, locu_t, INSERT_ALL_VALUES, u_t));
    6264:     PetscCall(DMRestoreLocalVector(dm, &locu_t));
    6265:   }
    6266:   PetscFunctionReturn(PETSC_SUCCESS);
    6267: }

    6269: static PetscErrorCode DMTransferDS_Internal(DM dm, DMLabel label, IS fields, PetscInt minDegree, PetscInt maxDegree, PetscDS ds, PetscDS dsIn)
    6270: {
    6271:   PetscDS dsNew, dsInNew = NULL;

    6273:   PetscFunctionBegin;
    6274:   PetscCall(PetscDSCreate(PetscObjectComm((PetscObject)ds), &dsNew));
    6275:   PetscCall(PetscDSCopy(ds, minDegree, maxDegree, dm, dsNew));
    6276:   if (dsIn) {
    6277:     PetscCall(PetscDSCreate(PetscObjectComm((PetscObject)dsIn), &dsInNew));
    6278:     PetscCall(PetscDSCopy(dsIn, minDegree, maxDegree, dm, dsInNew));
    6279:   }
    6280:   PetscCall(DMSetRegionDS(dm, label, fields, dsNew, dsInNew));
    6281:   PetscCall(PetscDSDestroy(&dsNew));
    6282:   PetscCall(PetscDSDestroy(&dsInNew));
    6283:   PetscFunctionReturn(PETSC_SUCCESS);
    6284: }

    6286: /*@
    6287:   DMCopyDS - Copy the discrete systems for the `DM` into another `DM`

    6289:   Collective

    6291:   Input Parameters:
    6292: + dm        - The `DM`
    6293: . minDegree - Minimum degree for a discretization, or `PETSC_DETERMINE` for no limit
    6294: - maxDegree - Maximum degree for a discretization, or `PETSC_DETERMINE` for no limit

    6296:   Output Parameter:
    6297: . newdm - The `DM`

    6299:   Level: advanced

    6301: .seealso: [](ch_dmbase), `DM`, `DMCopyFields()`, `DMAddField()`, `DMGetDS()`, `DMGetCellDS()`, `DMGetRegionDS()`, `DMSetRegionDS()`
    6302: @*/
    6303: PetscErrorCode DMCopyDS(DM dm, PetscInt minDegree, PetscInt maxDegree, DM newdm)
    6304: {
    6305:   PetscInt Nds, s;

    6307:   PetscFunctionBegin;
    6308:   if (dm == newdm) PetscFunctionReturn(PETSC_SUCCESS);
    6309:   PetscCall(DMGetNumDS(dm, &Nds));
    6310:   PetscCall(DMClearDS(newdm));
    6311:   for (s = 0; s < Nds; ++s) {
    6312:     DMLabel  label;
    6313:     IS       fields;
    6314:     PetscDS  ds, dsIn, newds;
    6315:     PetscInt Nbd, bd;

    6317:     PetscCall(DMGetRegionNumDS(dm, s, &label, &fields, &ds, &dsIn));
    6318:     /* TODO: We need to change all keys from labels in the old DM to labels in the new DM */
    6319:     PetscCall(DMTransferDS_Internal(newdm, label, fields, minDegree, maxDegree, ds, dsIn));
    6320:     /* Complete new labels in the new DS */
    6321:     PetscCall(DMGetRegionDS(newdm, label, NULL, &newds, NULL));
    6322:     PetscCall(PetscDSGetNumBoundary(newds, &Nbd));
    6323:     for (bd = 0; bd < Nbd; ++bd) {
    6324:       PetscWeakForm wf;
    6325:       DMLabel       label;
    6326:       PetscInt      field;

    6328:       PetscCall(PetscDSGetBoundary(newds, bd, &wf, NULL, NULL, &label, NULL, NULL, &field, NULL, NULL, NULL, NULL, NULL));
    6329:       PetscCall(PetscWeakFormReplaceLabel(wf, label));
    6330:     }
    6331:   }
    6332:   PetscCall(DMCompleteBCLabels_Internal(newdm));
    6333:   PetscFunctionReturn(PETSC_SUCCESS);
    6334: }

    6336: /*@
    6337:   DMCopyDisc - Copy the fields and discrete systems for the `DM` into another `DM`

    6339:   Collective

    6341:   Input Parameter:
    6342: . dm - The `DM`

    6344:   Output Parameter:
    6345: . newdm - The `DM`

    6347:   Level: advanced

    6349:   Developer Note:
    6350:   Really ugly name, nothing in PETSc is called a `Disc` plus it is an ugly abbreviation

    6352: .seealso: [](ch_dmbase), `DM`, `DMCopyFields()`, `DMCopyDS()`
    6353: @*/
    6354: PetscErrorCode DMCopyDisc(DM dm, DM newdm)
    6355: {
    6356:   PetscFunctionBegin;
    6357:   PetscCall(DMCopyFields(dm, PETSC_DETERMINE, PETSC_DETERMINE, newdm));
    6358:   PetscCall(DMCopyDS(dm, PETSC_DETERMINE, PETSC_DETERMINE, newdm));
    6359:   PetscFunctionReturn(PETSC_SUCCESS);
    6360: }

    6362: /*@
    6363:   DMGetDimension - Return the topological dimension of the `DM`

    6365:   Not Collective

    6367:   Input Parameter:
    6368: . dm - The `DM`

    6370:   Output Parameter:
    6371: . dim - The topological dimension

    6373:   Level: beginner

    6375: .seealso: [](ch_dmbase), `DM`, `DMSetDimension()`, `DMCreate()`
    6376: @*/
    6377: PetscErrorCode DMGetDimension(DM dm, PetscInt *dim)
    6378: {
    6379:   PetscFunctionBegin;
    6381:   PetscAssertPointer(dim, 2);
    6382:   *dim = dm->dim;
    6383:   PetscFunctionReturn(PETSC_SUCCESS);
    6384: }

    6386: /*@
    6387:   DMSetDimension - Set the topological dimension of the `DM`

    6389:   Collective

    6391:   Input Parameters:
    6392: + dm  - The `DM`
    6393: - dim - The topological dimension

    6395:   Level: beginner

    6397: .seealso: [](ch_dmbase), `DM`, `DMGetDimension()`, `DMCreate()`
    6398: @*/
    6399: PetscErrorCode DMSetDimension(DM dm, PetscInt dim)
    6400: {
    6401:   PetscDS  ds;
    6402:   PetscInt Nds, n;

    6404:   PetscFunctionBegin;
    6407:   dm->dim = dim;
    6408:   if (dm->dim >= 0) {
    6409:     PetscCall(DMGetNumDS(dm, &Nds));
    6410:     for (n = 0; n < Nds; ++n) {
    6411:       PetscCall(DMGetRegionNumDS(dm, n, NULL, NULL, &ds, NULL));
    6412:       if (ds->dimEmbed < 0) PetscCall(PetscDSSetCoordinateDimension(ds, dim));
    6413:     }
    6414:   }
    6415:   PetscFunctionReturn(PETSC_SUCCESS);
    6416: }

    6418: /*@
    6419:   DMGetDimPoints - Get the half-open interval for all points of a given dimension

    6421:   Collective

    6423:   Input Parameters:
    6424: + dm  - the `DM`
    6425: - dim - the dimension

    6427:   Output Parameters:
    6428: + pStart - The first point of the given dimension
    6429: - pEnd   - The first point following points of the given dimension

    6431:   Level: intermediate

    6433:   Note:
    6434:   The points are vertices in the Hasse diagram encoding the topology. This is explained in
    6435:   https://arxiv.org/abs/0908.4427. If no points exist of this dimension in the storage scheme,
    6436:   then the interval is empty.

    6438: .seealso: [](ch_dmbase), `DM`, `DMPLEX`, `DMPlexGetDepthStratum()`, `DMPlexGetHeightStratum()`
    6439: @*/
    6440: PetscErrorCode DMGetDimPoints(DM dm, PetscInt dim, PetscInt *pStart, PetscInt *pEnd)
    6441: {
    6442:   PetscInt d;

    6444:   PetscFunctionBegin;
    6446:   PetscCall(DMGetDimension(dm, &d));
    6447:   PetscCheck((dim >= 0) && (dim <= d), PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Invalid dimension %" PetscInt_FMT, dim);
    6448:   PetscUseTypeMethod(dm, getdimpoints, dim, pStart, pEnd);
    6449:   PetscFunctionReturn(PETSC_SUCCESS);
    6450: }

    6452: /*@
    6453:   DMGetOutputDM - Retrieve the `DM` associated with the layout for output

    6455:   Collective

    6457:   Input Parameter:
    6458: . dm - The original `DM`

    6460:   Output Parameter:
    6461: . odm - The `DM` which provides the layout for output

    6463:   Level: intermediate

    6465:   Note:
    6466:   In some situations the vector obtained with `DMCreateGlobalVector()` excludes points for degrees of freedom that are associated with fixed (Dirichelet) boundary
    6467:   conditions since the algebraic solver does not solve for those variables. The output `DM` includes these excluded points and its global vector contains the
    6468:   locations for those dof so that they can be output to a file or other viewer along with the unconstrained dof.

    6470: .seealso: [](ch_dmbase), `DM`, `VecView()`, `DMGetGlobalSection()`, `DMCreateGlobalVector()`, `PetscSectionHasConstraints()`, `DMSetGlobalSection()`
    6471: @*/
    6472: PetscErrorCode DMGetOutputDM(DM dm, DM *odm)
    6473: {
    6474:   PetscSection section;
    6475:   IS           perm;
    6476:   PetscBool    hasConstraints, newDM, gnewDM;
    6477:   PetscInt     num_face_sfs = 0;

    6479:   PetscFunctionBegin;
    6481:   PetscAssertPointer(odm, 2);
    6482:   PetscCall(DMGetLocalSection(dm, &section));
    6483:   PetscCall(PetscSectionHasConstraints(section, &hasConstraints));
    6484:   PetscCall(PetscSectionGetPermutation(section, &perm));
    6485:   PetscCall(DMPlexGetIsoperiodicFaceSF(dm, &num_face_sfs, NULL));
    6486:   newDM = hasConstraints || perm || (num_face_sfs > 0) ? PETSC_TRUE : PETSC_FALSE;
    6487:   PetscCallMPI(MPIU_Allreduce(&newDM, &gnewDM, 1, MPIU_BOOL, MPI_LOR, PetscObjectComm((PetscObject)dm)));
    6488:   if (!gnewDM) {
    6489:     *odm = dm;
    6490:     PetscFunctionReturn(PETSC_SUCCESS);
    6491:   }
    6492:   if (!dm->dmBC) {
    6493:     PetscSection newSection, gsection;
    6494:     PetscSF      sf, sfNatural;
    6495:     PetscBool    usePerm = dm->ignorePermOutput ? PETSC_FALSE : PETSC_TRUE;

    6497:     PetscCall(DMClone(dm, &dm->dmBC));
    6498:     PetscCall(DMCopyDisc(dm, dm->dmBC));
    6499:     PetscCall(PetscSectionClone(section, &newSection));
    6500:     PetscCall(DMSetLocalSection(dm->dmBC, newSection));
    6501:     PetscCall(PetscSectionDestroy(&newSection));
    6502:     PetscCall(DMGetNaturalSF(dm, &sfNatural));
    6503:     PetscCall(DMSetNaturalSF(dm->dmBC, sfNatural));
    6504:     PetscCall(DMGetPointSF(dm->dmBC, &sf));
    6505:     PetscCall(PetscSectionCreateGlobalSection(section, sf, usePerm, PETSC_TRUE, PETSC_FALSE, &gsection));
    6506:     PetscCall(DMSetGlobalSection(dm->dmBC, gsection));
    6507:     PetscCall(PetscSectionDestroy(&gsection));
    6508:   }
    6509:   *odm = dm->dmBC;
    6510:   PetscFunctionReturn(PETSC_SUCCESS);
    6511: }

    6513: /*@
    6514:   DMGetOutputSequenceNumber - Retrieve the sequence number/value for output

    6516:   Input Parameter:
    6517: . dm - The original `DM`

    6519:   Output Parameters:
    6520: + num - The output sequence number
    6521: - val - The output sequence value

    6523:   Level: intermediate

    6525:   Note:
    6526:   This is intended for output that should appear in sequence, for instance
    6527:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6529:   Developer Note:
    6530:   The `DM` serves as a convenient place to store the current iteration value. The iteration is not
    6531:   not directly related to the `DM`.

    6533: .seealso: [](ch_dmbase), `DM`, `VecView()`
    6534: @*/
    6535: PetscErrorCode DMGetOutputSequenceNumber(DM dm, PetscInt *num, PetscReal *val)
    6536: {
    6537:   PetscFunctionBegin;
    6539:   if (num) {
    6540:     PetscAssertPointer(num, 2);
    6541:     *num = dm->outputSequenceNum;
    6542:   }
    6543:   if (val) {
    6544:     PetscAssertPointer(val, 3);
    6545:     *val = dm->outputSequenceVal;
    6546:   }
    6547:   PetscFunctionReturn(PETSC_SUCCESS);
    6548: }

    6550: /*@
    6551:   DMSetOutputSequenceNumber - Set the sequence number/value for output

    6553:   Input Parameters:
    6554: + dm  - The original `DM`
    6555: . num - The output sequence number
    6556: - val - The output sequence value

    6558:   Level: intermediate

    6560:   Note:
    6561:   This is intended for output that should appear in sequence, for instance
    6562:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6564: .seealso: [](ch_dmbase), `DM`, `VecView()`
    6565: @*/
    6566: PetscErrorCode DMSetOutputSequenceNumber(DM dm, PetscInt num, PetscReal val)
    6567: {
    6568:   PetscFunctionBegin;
    6570:   dm->outputSequenceNum = num;
    6571:   dm->outputSequenceVal = val;
    6572:   PetscFunctionReturn(PETSC_SUCCESS);
    6573: }

    6575: /*@
    6576:   DMOutputSequenceLoad - Retrieve the sequence value from a `PetscViewer`

    6578:   Input Parameters:
    6579: + dm     - The original `DM`
    6580: . viewer - The `PetscViewer` to get it from
    6581: . name   - The sequence name
    6582: - num    - The output sequence number

    6584:   Output Parameter:
    6585: . val - The output sequence value

    6587:   Level: intermediate

    6589:   Note:
    6590:   This is intended for output that should appear in sequence, for instance
    6591:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6593:   Developer Note:
    6594:   It is unclear at the user API level why a `DM` is needed as input

    6596: .seealso: [](ch_dmbase), `DM`, `DMGetOutputSequenceNumber()`, `DMSetOutputSequenceNumber()`, `VecView()`
    6597: @*/
    6598: PetscErrorCode DMOutputSequenceLoad(DM dm, PetscViewer viewer, const char name[], PetscInt num, PetscReal *val)
    6599: {
    6600:   PetscBool ishdf5;

    6602:   PetscFunctionBegin;
    6605:   PetscAssertPointer(name, 3);
    6606:   PetscAssertPointer(val, 5);
    6607:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
    6608:   if (ishdf5) {
    6609: #if defined(PETSC_HAVE_HDF5)
    6610:     PetscScalar value;

    6612:     PetscCall(DMSequenceLoad_HDF5_Internal(dm, name, num, &value, viewer));
    6613:     *val = PetscRealPart(value);
    6614: #endif
    6615:   } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerHDF5Open()");
    6616:   PetscFunctionReturn(PETSC_SUCCESS);
    6617: }

    6619: /*@
    6620:   DMGetOutputSequenceLength - Retrieve the number of sequence values from a `PetscViewer`

    6622:   Input Parameters:
    6623: + dm     - The original `DM`
    6624: . viewer - The `PetscViewer` to get it from
    6625: - name   - The sequence name

    6627:   Output Parameter:
    6628: . len - The length of the output sequence

    6630:   Level: intermediate

    6632:   Note:
    6633:   This is intended for output that should appear in sequence, for instance
    6634:   a set of timesteps in an `PETSCVIEWERHDF5` file, or a set of realizations of a stochastic system.

    6636:   Developer Note:
    6637:   It is unclear at the user API level why a `DM` is needed as input

    6639: .seealso: [](ch_dmbase), `DM`, `DMGetOutputSequenceNumber()`, `DMSetOutputSequenceNumber()`, `VecView()`
    6640: @*/
    6641: PetscErrorCode DMGetOutputSequenceLength(DM dm, PetscViewer viewer, const char name[], PetscInt *len)
    6642: {
    6643:   PetscBool ishdf5;

    6645:   PetscFunctionBegin;
    6648:   PetscAssertPointer(name, 3);
    6649:   PetscAssertPointer(len, 4);
    6650:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
    6651:   if (ishdf5) {
    6652: #if defined(PETSC_HAVE_HDF5)
    6653:     PetscCall(DMSequenceGetLength_HDF5_Internal(dm, name, len, viewer));
    6654: #endif
    6655:   } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid viewer; open viewer with PetscViewerHDF5Open()");
    6656:   PetscFunctionReturn(PETSC_SUCCESS);
    6657: }

    6659: /*@
    6660:   DMGetUseNatural - Get the flag for creating a mapping to the natural order when a `DM` is (re)distributed in parallel

    6662:   Not Collective

    6664:   Input Parameter:
    6665: . dm - The `DM`

    6667:   Output Parameter:
    6668: . useNatural - `PETSC_TRUE` to build the mapping to a natural order during distribution

    6670:   Level: beginner

    6672: .seealso: [](ch_dmbase), `DM`, `DMSetUseNatural()`, `DMCreate()`
    6673: @*/
    6674: PetscErrorCode DMGetUseNatural(DM dm, PetscBool *useNatural)
    6675: {
    6676:   PetscFunctionBegin;
    6678:   PetscAssertPointer(useNatural, 2);
    6679:   *useNatural = dm->useNatural;
    6680:   PetscFunctionReturn(PETSC_SUCCESS);
    6681: }

    6683: /*@
    6684:   DMSetUseNatural - Set the flag for creating a mapping to the natural order when a `DM` is (re)distributed in parallel

    6686:   Collective

    6688:   Input Parameters:
    6689: + dm         - The `DM`
    6690: - useNatural - `PETSC_TRUE` to build the mapping to a natural order during distribution

    6692:   Level: beginner

    6694:   Note:
    6695:   This also causes the map to be build after `DMCreateSubDM()` and `DMCreateSuperDM()`

    6697: .seealso: [](ch_dmbase), `DM`, `DMGetUseNatural()`, `DMCreate()`, `DMPlexDistribute()`, `DMCreateSubDM()`, `DMCreateSuperDM()`
    6698: @*/
    6699: PetscErrorCode DMSetUseNatural(DM dm, PetscBool useNatural)
    6700: {
    6701:   PetscFunctionBegin;
    6704:   dm->useNatural = useNatural;
    6705:   PetscFunctionReturn(PETSC_SUCCESS);
    6706: }

    6708: /*@
    6709:   DMCreateLabel - Create a label of the given name if it does not already exist in the `DM`

    6711:   Not Collective

    6713:   Input Parameters:
    6714: + dm   - The `DM` object
    6715: - name - The label name

    6717:   Level: intermediate

    6719: .seealso: [](ch_dmbase), `DM`, `DMLabelCreate()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6720: @*/
    6721: PetscErrorCode DMCreateLabel(DM dm, const char name[])
    6722: {
    6723:   PetscBool flg;
    6724:   DMLabel   label;

    6726:   PetscFunctionBegin;
    6728:   PetscAssertPointer(name, 2);
    6729:   PetscCall(DMHasLabel(dm, name, &flg));
    6730:   if (!flg) {
    6731:     PetscCall(DMLabelCreate(PETSC_COMM_SELF, name, &label));
    6732:     PetscCall(DMAddLabel(dm, label));
    6733:     PetscCall(DMLabelDestroy(&label));
    6734:   }
    6735:   PetscFunctionReturn(PETSC_SUCCESS);
    6736: }

    6738: /*@
    6739:   DMCreateLabelAtIndex - Create a label of the given name at the given index. If it already exists in the `DM`, move it to this index.

    6741:   Not Collective

    6743:   Input Parameters:
    6744: + dm   - The `DM` object
    6745: . l    - The index for the label
    6746: - name - The label name

    6748:   Level: intermediate

    6750: .seealso: [](ch_dmbase), `DM`, `DMCreateLabel()`, `DMLabelCreate()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6751: @*/
    6752: PetscErrorCode DMCreateLabelAtIndex(DM dm, PetscInt l, const char name[])
    6753: {
    6754:   DMLabelLink orig, prev = NULL;
    6755:   DMLabel     label;
    6756:   PetscInt    Nl, m;
    6757:   PetscBool   flg, match;
    6758:   const char *lname;

    6760:   PetscFunctionBegin;
    6762:   PetscAssertPointer(name, 3);
    6763:   PetscCall(DMHasLabel(dm, name, &flg));
    6764:   if (!flg) {
    6765:     PetscCall(DMLabelCreate(PETSC_COMM_SELF, name, &label));
    6766:     PetscCall(DMAddLabel(dm, label));
    6767:     PetscCall(DMLabelDestroy(&label));
    6768:   }
    6769:   PetscCall(DMGetNumLabels(dm, &Nl));
    6770:   PetscCheck(l < Nl, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label index %" PetscInt_FMT " must be in [0, %" PetscInt_FMT ")", l, Nl);
    6771:   for (m = 0, orig = dm->labels; m < Nl; ++m, prev = orig, orig = orig->next) {
    6772:     PetscCall(PetscObjectGetName((PetscObject)orig->label, &lname));
    6773:     PetscCall(PetscStrcmp(name, lname, &match));
    6774:     if (match) break;
    6775:   }
    6776:   if (m == l) PetscFunctionReturn(PETSC_SUCCESS);
    6777:   if (!m) dm->labels = orig->next;
    6778:   else prev->next = orig->next;
    6779:   if (!l) {
    6780:     orig->next = dm->labels;
    6781:     dm->labels = orig;
    6782:   } else {
    6783:     for (m = 0, prev = dm->labels; m < l - 1; ++m, prev = prev->next);
    6784:     orig->next = prev->next;
    6785:     prev->next = orig;
    6786:   }
    6787:   PetscFunctionReturn(PETSC_SUCCESS);
    6788: }

    6790: /*@
    6791:   DMGetLabelValue - Get the value in a `DMLabel` for the given point, with -1 as the default

    6793:   Not Collective

    6795:   Input Parameters:
    6796: + dm    - The `DM` object
    6797: . name  - The label name
    6798: - point - The mesh point

    6800:   Output Parameter:
    6801: . value - The label value for this point, or -1 if the point is not in the label

    6803:   Level: beginner

    6805: .seealso: [](ch_dmbase), `DM`, `DMLabelGetValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6806: @*/
    6807: PetscErrorCode DMGetLabelValue(DM dm, const char name[], PetscInt point, PetscInt *value)
    6808: {
    6809:   DMLabel label;

    6811:   PetscFunctionBegin;
    6813:   PetscAssertPointer(name, 2);
    6814:   PetscCall(DMGetLabel(dm, name, &label));
    6815:   PetscCheck(label, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "No label named %s was found", name);
    6816:   PetscCall(DMLabelGetValue(label, point, value));
    6817:   PetscFunctionReturn(PETSC_SUCCESS);
    6818: }

    6820: /*@
    6821:   DMSetLabelValue - Add a point to a `DMLabel` with given value

    6823:   Not Collective

    6825:   Input Parameters:
    6826: + dm    - The `DM` object
    6827: . name  - The label name
    6828: . point - The mesh point
    6829: - value - The label value for this point

    6831:   Output Parameter:

    6833:   Level: beginner

    6835: .seealso: [](ch_dmbase), `DM`, `DMLabelSetValue()`, `DMGetStratumIS()`, `DMClearLabelValue()`
    6836: @*/
    6837: PetscErrorCode DMSetLabelValue(DM dm, const char name[], PetscInt point, PetscInt value)
    6838: {
    6839:   DMLabel label;

    6841:   PetscFunctionBegin;
    6843:   PetscAssertPointer(name, 2);
    6844:   PetscCall(DMGetLabel(dm, name, &label));
    6845:   if (!label) {
    6846:     PetscCall(DMCreateLabel(dm, name));
    6847:     PetscCall(DMGetLabel(dm, name, &label));
    6848:   }
    6849:   PetscCall(DMLabelSetValue(label, point, value));
    6850:   PetscFunctionReturn(PETSC_SUCCESS);
    6851: }

    6853: /*@
    6854:   DMClearLabelValue - Remove a point from a `DMLabel` with given value

    6856:   Not Collective

    6858:   Input Parameters:
    6859: + dm    - The `DM` object
    6860: . name  - The label name
    6861: . point - The mesh point
    6862: - value - The label value for this point

    6864:   Level: beginner

    6866: .seealso: [](ch_dmbase), `DM`, `DMLabelClearValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    6867: @*/
    6868: PetscErrorCode DMClearLabelValue(DM dm, const char name[], PetscInt point, PetscInt value)
    6869: {
    6870:   DMLabel label;

    6872:   PetscFunctionBegin;
    6874:   PetscAssertPointer(name, 2);
    6875:   PetscCall(DMGetLabel(dm, name, &label));
    6876:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    6877:   PetscCall(DMLabelClearValue(label, point, value));
    6878:   PetscFunctionReturn(PETSC_SUCCESS);
    6879: }

    6881: /*@
    6882:   DMGetLabelSize - Get the value of `DMLabelGetNumValues()` of a `DMLabel` in the `DM`

    6884:   Not Collective

    6886:   Input Parameters:
    6887: + dm   - The `DM` object
    6888: - name - The label name

    6890:   Output Parameter:
    6891: . size - The number of different integer ids, or 0 if the label does not exist

    6893:   Level: beginner

    6895:   Developer Note:
    6896:   This should be renamed to something like `DMGetLabelNumValues()` or removed.

    6898: .seealso: [](ch_dmbase), `DM`, `DMLabelGetNumValues()`, `DMSetLabelValue()`, `DMGetLabel()`
    6899: @*/
    6900: PetscErrorCode DMGetLabelSize(DM dm, const char name[], PetscInt *size)
    6901: {
    6902:   DMLabel label;

    6904:   PetscFunctionBegin;
    6906:   PetscAssertPointer(name, 2);
    6907:   PetscAssertPointer(size, 3);
    6908:   PetscCall(DMGetLabel(dm, name, &label));
    6909:   *size = 0;
    6910:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    6911:   PetscCall(DMLabelGetNumValues(label, size));
    6912:   PetscFunctionReturn(PETSC_SUCCESS);
    6913: }

    6915: /*@
    6916:   DMGetLabelIdIS - Get the `DMLabelGetValueIS()` from a `DMLabel` in the `DM`

    6918:   Not Collective

    6920:   Input Parameters:
    6921: + dm   - The `DM` object
    6922: - name - The label name

    6924:   Output Parameter:
    6925: . ids - The integer ids, or `NULL` if the label does not exist

    6927:   Level: beginner

    6929: .seealso: [](ch_dmbase), `DM`, `DMLabelGetValueIS()`, `DMGetLabelSize()`
    6930: @*/
    6931: PetscErrorCode DMGetLabelIdIS(DM dm, const char name[], IS *ids)
    6932: {
    6933:   DMLabel label;

    6935:   PetscFunctionBegin;
    6937:   PetscAssertPointer(name, 2);
    6938:   PetscAssertPointer(ids, 3);
    6939:   PetscCall(DMGetLabel(dm, name, &label));
    6940:   *ids = NULL;
    6941:   if (label) {
    6942:     PetscCall(DMLabelGetValueIS(label, ids));
    6943:   } else {
    6944:     /* returning an empty IS */
    6945:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, 0, NULL, PETSC_USE_POINTER, ids));
    6946:   }
    6947:   PetscFunctionReturn(PETSC_SUCCESS);
    6948: }

    6950: /*@
    6951:   DMGetStratumSize - Get the number of points in a label stratum

    6953:   Not Collective

    6955:   Input Parameters:
    6956: + dm    - The `DM` object
    6957: . name  - The label name of the stratum
    6958: - value - The stratum value

    6960:   Output Parameter:
    6961: . size - The number of points, also called the stratum size

    6963:   Level: beginner

    6965: .seealso: [](ch_dmbase), `DM`, `DMLabelGetStratumSize()`, `DMGetLabelSize()`, `DMGetLabelIds()`
    6966: @*/
    6967: PetscErrorCode DMGetStratumSize(DM dm, const char name[], PetscInt value, PetscInt *size)
    6968: {
    6969:   DMLabel label;

    6971:   PetscFunctionBegin;
    6973:   PetscAssertPointer(name, 2);
    6974:   PetscAssertPointer(size, 4);
    6975:   PetscCall(DMGetLabel(dm, name, &label));
    6976:   *size = 0;
    6977:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    6978:   PetscCall(DMLabelGetStratumSize(label, value, size));
    6979:   PetscFunctionReturn(PETSC_SUCCESS);
    6980: }

    6982: /*@
    6983:   DMGetStratumIS - Get the points in a label stratum

    6985:   Not Collective

    6987:   Input Parameters:
    6988: + dm    - The `DM` object
    6989: . name  - The label name
    6990: - value - The stratum value

    6992:   Output Parameter:
    6993: . points - The stratum points, or `NULL` if the label does not exist or does not have that value

    6995:   Level: beginner

    6997: .seealso: [](ch_dmbase), `DM`, `DMLabelGetStratumIS()`, `DMGetStratumSize()`
    6998: @*/
    6999: PetscErrorCode DMGetStratumIS(DM dm, const char name[], PetscInt value, IS *points)
    7000: {
    7001:   DMLabel label;

    7003:   PetscFunctionBegin;
    7005:   PetscAssertPointer(name, 2);
    7006:   PetscAssertPointer(points, 4);
    7007:   PetscCall(DMGetLabel(dm, name, &label));
    7008:   *points = NULL;
    7009:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7010:   PetscCall(DMLabelGetStratumIS(label, value, points));
    7011:   PetscFunctionReturn(PETSC_SUCCESS);
    7012: }

    7014: /*@
    7015:   DMSetStratumIS - Set the points in a label stratum

    7017:   Not Collective

    7019:   Input Parameters:
    7020: + dm     - The `DM` object
    7021: . name   - The label name
    7022: . value  - The stratum value
    7023: - points - The stratum points

    7025:   Level: beginner

    7027: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMClearLabelStratum()`, `DMLabelClearStratum()`, `DMLabelSetStratumIS()`, `DMGetStratumSize()`
    7028: @*/
    7029: PetscErrorCode DMSetStratumIS(DM dm, const char name[], PetscInt value, IS points)
    7030: {
    7031:   DMLabel label;

    7033:   PetscFunctionBegin;
    7035:   PetscAssertPointer(name, 2);
    7037:   PetscCall(DMGetLabel(dm, name, &label));
    7038:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7039:   PetscCall(DMLabelSetStratumIS(label, value, points));
    7040:   PetscFunctionReturn(PETSC_SUCCESS);
    7041: }

    7043: /*@
    7044:   DMClearLabelStratum - Remove all points from a stratum from a `DMLabel`

    7046:   Not Collective

    7048:   Input Parameters:
    7049: + dm    - The `DM` object
    7050: . name  - The label name
    7051: - value - The label value for this point

    7053:   Output Parameter:

    7055:   Level: beginner

    7057: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMLabelClearStratum()`, `DMSetLabelValue()`, `DMGetStratumIS()`, `DMClearLabelValue()`
    7058: @*/
    7059: PetscErrorCode DMClearLabelStratum(DM dm, const char name[], PetscInt value)
    7060: {
    7061:   DMLabel label;

    7063:   PetscFunctionBegin;
    7065:   PetscAssertPointer(name, 2);
    7066:   PetscCall(DMGetLabel(dm, name, &label));
    7067:   if (!label) PetscFunctionReturn(PETSC_SUCCESS);
    7068:   PetscCall(DMLabelClearStratum(label, value));
    7069:   PetscFunctionReturn(PETSC_SUCCESS);
    7070: }

    7072: /*@
    7073:   DMGetNumLabels - Return the number of labels defined by on the `DM`

    7075:   Not Collective

    7077:   Input Parameter:
    7078: . dm - The `DM` object

    7080:   Output Parameter:
    7081: . numLabels - the number of Labels

    7083:   Level: intermediate

    7085: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetLabelByNum()`, `DMGetLabelName()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7086: @*/
    7087: PetscErrorCode DMGetNumLabels(DM dm, PetscInt *numLabels)
    7088: {
    7089:   DMLabelLink next = dm->labels;
    7090:   PetscInt    n    = 0;

    7092:   PetscFunctionBegin;
    7094:   PetscAssertPointer(numLabels, 2);
    7095:   while (next) {
    7096:     ++n;
    7097:     next = next->next;
    7098:   }
    7099:   *numLabels = n;
    7100:   PetscFunctionReturn(PETSC_SUCCESS);
    7101: }

    7103: /*@
    7104:   DMGetLabelName - Return the name of nth label

    7106:   Not Collective

    7108:   Input Parameters:
    7109: + dm - The `DM` object
    7110: - n  - the label number

    7112:   Output Parameter:
    7113: . name - the label name

    7115:   Level: intermediate

    7117:   Developer Note:
    7118:   Some of the functions that appropriate on labels using their number have the suffix ByNum, others do not.

    7120: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetLabelByNum()`, `DMGetLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7121: @*/
    7122: PetscErrorCode DMGetLabelName(DM dm, PetscInt n, const char *name[])
    7123: {
    7124:   DMLabelLink next = dm->labels;
    7125:   PetscInt    l    = 0;

    7127:   PetscFunctionBegin;
    7129:   PetscAssertPointer(name, 3);
    7130:   while (next) {
    7131:     if (l == n) {
    7132:       PetscCall(PetscObjectGetName((PetscObject)next->label, name));
    7133:       PetscFunctionReturn(PETSC_SUCCESS);
    7134:     }
    7135:     ++l;
    7136:     next = next->next;
    7137:   }
    7138:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label %" PetscInt_FMT " does not exist in this DM", n);
    7139: }

    7141: /*@
    7142:   DMHasLabel - Determine whether the `DM` has a label of a given name

    7144:   Not Collective

    7146:   Input Parameters:
    7147: + dm   - The `DM` object
    7148: - name - The label name

    7150:   Output Parameter:
    7151: . hasLabel - `PETSC_TRUE` if the label is present

    7153:   Level: intermediate

    7155: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetLabel()`, `DMGetLabelByNum()`, `DMCreateLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7156: @*/
    7157: PetscErrorCode DMHasLabel(DM dm, const char name[], PetscBool *hasLabel)
    7158: {
    7159:   DMLabelLink next = dm->labels;
    7160:   const char *lname;

    7162:   PetscFunctionBegin;
    7164:   PetscAssertPointer(name, 2);
    7165:   PetscAssertPointer(hasLabel, 3);
    7166:   *hasLabel = PETSC_FALSE;
    7167:   while (next) {
    7168:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7169:     PetscCall(PetscStrcmp(name, lname, hasLabel));
    7170:     if (*hasLabel) break;
    7171:     next = next->next;
    7172:   }
    7173:   PetscFunctionReturn(PETSC_SUCCESS);
    7174: }

    7176: // PetscClangLinter pragma ignore: -fdoc-section-header-unknown
    7177: /*@
    7178:   DMGetLabel - Return the label of a given name, or `NULL`, from a `DM`

    7180:   Not Collective

    7182:   Input Parameters:
    7183: + dm   - The `DM` object
    7184: - name - The label name

    7186:   Output Parameter:
    7187: . label - The `DMLabel`, or `NULL` if the label is absent

    7189:   Default labels in a `DMPLEX`:
    7190: + "depth"       - Holds the depth (co-dimension) of each mesh point
    7191: . "celltype"    - Holds the topological type of each cell
    7192: . "ghost"       - If the DM is distributed with overlap, this marks the cells and faces in the overlap
    7193: . "Cell Sets"   - Mirrors the cell sets defined by GMsh and ExodusII
    7194: . "Face Sets"   - Mirrors the face sets defined by GMsh and ExodusII
    7195: - "Vertex Sets" - Mirrors the vertex sets defined by GMsh

    7197:   Level: intermediate

    7199: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMHasLabel()`, `DMGetLabelByNum()`, `DMAddLabel()`, `DMCreateLabel()`, `DMPlexGetDepthLabel()`, `DMPlexGetCellType()`
    7200: @*/
    7201: PetscErrorCode DMGetLabel(DM dm, const char name[], DMLabel *label)
    7202: {
    7203:   DMLabelLink next = dm->labels;
    7204:   PetscBool   hasLabel;
    7205:   const char *lname;

    7207:   PetscFunctionBegin;
    7209:   PetscAssertPointer(name, 2);
    7210:   PetscAssertPointer(label, 3);
    7211:   *label = NULL;
    7212:   while (next) {
    7213:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7214:     PetscCall(PetscStrcmp(name, lname, &hasLabel));
    7215:     if (hasLabel) {
    7216:       *label = next->label;
    7217:       break;
    7218:     }
    7219:     next = next->next;
    7220:   }
    7221:   PetscFunctionReturn(PETSC_SUCCESS);
    7222: }

    7224: /*@
    7225:   DMGetLabelByNum - Return the nth label on a `DM`

    7227:   Not Collective

    7229:   Input Parameters:
    7230: + dm - The `DM` object
    7231: - n  - the label number

    7233:   Output Parameter:
    7234: . label - the label

    7236:   Level: intermediate

    7238: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMAddLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7239: @*/
    7240: PetscErrorCode DMGetLabelByNum(DM dm, PetscInt n, DMLabel *label)
    7241: {
    7242:   DMLabelLink next = dm->labels;
    7243:   PetscInt    l    = 0;

    7245:   PetscFunctionBegin;
    7247:   PetscAssertPointer(label, 3);
    7248:   while (next) {
    7249:     if (l == n) {
    7250:       *label = next->label;
    7251:       PetscFunctionReturn(PETSC_SUCCESS);
    7252:     }
    7253:     ++l;
    7254:     next = next->next;
    7255:   }
    7256:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label %" PetscInt_FMT " does not exist in this DM", n);
    7257: }

    7259: /*@
    7260:   DMAddLabel - Add the label to this `DM`

    7262:   Not Collective

    7264:   Input Parameters:
    7265: + dm    - The `DM` object
    7266: - label - The `DMLabel`

    7268:   Level: developer

    7270: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7271: @*/
    7272: PetscErrorCode DMAddLabel(DM dm, DMLabel label)
    7273: {
    7274:   DMLabelLink l, *p, tmpLabel;
    7275:   PetscBool   hasLabel;
    7276:   const char *lname;
    7277:   PetscBool   flg;

    7279:   PetscFunctionBegin;
    7281:   PetscCall(PetscObjectGetName((PetscObject)label, &lname));
    7282:   PetscCall(DMHasLabel(dm, lname, &hasLabel));
    7283:   PetscCheck(!hasLabel, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Label %s already exists in this DM", lname);
    7284:   PetscCall(PetscCalloc1(1, &tmpLabel));
    7285:   tmpLabel->label  = label;
    7286:   tmpLabel->output = PETSC_TRUE;
    7287:   for (p = &dm->labels; (l = *p); p = &l->next) { }
    7288:   *p = tmpLabel;
    7289:   PetscCall(PetscObjectReference((PetscObject)label));
    7290:   PetscCall(PetscStrcmp(lname, "depth", &flg));
    7291:   if (flg) dm->depthLabel = label;
    7292:   PetscCall(PetscStrcmp(lname, "celltype", &flg));
    7293:   if (flg) dm->celltypeLabel = label;
    7294:   PetscFunctionReturn(PETSC_SUCCESS);
    7295: }

    7297: // PetscClangLinter pragma ignore: -fdoc-section-header-unknown
    7298: /*@
    7299:   DMSetLabel - Replaces the label of a given name, or ignores it if the name is not present

    7301:   Not Collective

    7303:   Input Parameters:
    7304: + dm    - The `DM` object
    7305: - label - The `DMLabel`, having the same name, to substitute

    7307:   Default labels in a `DMPLEX`:
    7308: + "depth"       - Holds the depth (co-dimension) of each mesh point
    7309: . "celltype"    - Holds the topological type of each cell
    7310: . "ghost"       - If the DM is distributed with overlap, this marks the cells and faces in the overlap
    7311: . "Cell Sets"   - Mirrors the cell sets defined by GMsh and ExodusII
    7312: . "Face Sets"   - Mirrors the face sets defined by GMsh and ExodusII
    7313: - "Vertex Sets" - Mirrors the vertex sets defined by GMsh

    7315:   Level: intermediate

    7317: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMPlexGetDepthLabel()`, `DMPlexGetCellType()`
    7318: @*/
    7319: PetscErrorCode DMSetLabel(DM dm, DMLabel label)
    7320: {
    7321:   DMLabelLink next = dm->labels;
    7322:   PetscBool   hasLabel, flg;
    7323:   const char *name, *lname;

    7325:   PetscFunctionBegin;
    7328:   PetscCall(PetscObjectGetName((PetscObject)label, &name));
    7329:   while (next) {
    7330:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7331:     PetscCall(PetscStrcmp(name, lname, &hasLabel));
    7332:     if (hasLabel) {
    7333:       PetscCall(PetscObjectReference((PetscObject)label));
    7334:       PetscCall(PetscStrcmp(lname, "depth", &flg));
    7335:       if (flg) dm->depthLabel = label;
    7336:       PetscCall(PetscStrcmp(lname, "celltype", &flg));
    7337:       if (flg) dm->celltypeLabel = label;
    7338:       PetscCall(DMLabelDestroy(&next->label));
    7339:       next->label = label;
    7340:       break;
    7341:     }
    7342:     next = next->next;
    7343:   }
    7344:   PetscFunctionReturn(PETSC_SUCCESS);
    7345: }

    7347: /*@
    7348:   DMRemoveLabel - Remove the label given by name from this `DM`

    7350:   Not Collective

    7352:   Input Parameters:
    7353: + dm   - The `DM` object
    7354: - name - The label name

    7356:   Output Parameter:
    7357: . label - The `DMLabel`, or `NULL` if the label is absent. Pass in `NULL` to call `DMLabelDestroy()` on the label, otherwise the
    7358:           caller is responsible for calling `DMLabelDestroy()`.

    7360:   Level: developer

    7362: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMLabelDestroy()`, `DMRemoveLabelBySelf()`
    7363: @*/
    7364: PetscErrorCode DMRemoveLabel(DM dm, const char name[], DMLabel *label)
    7365: {
    7366:   DMLabelLink link, *pnext;
    7367:   PetscBool   hasLabel;
    7368:   const char *lname;

    7370:   PetscFunctionBegin;
    7372:   PetscAssertPointer(name, 2);
    7373:   if (label) {
    7374:     PetscAssertPointer(label, 3);
    7375:     *label = NULL;
    7376:   }
    7377:   for (pnext = &dm->labels; (link = *pnext); pnext = &link->next) {
    7378:     PetscCall(PetscObjectGetName((PetscObject)link->label, &lname));
    7379:     PetscCall(PetscStrcmp(name, lname, &hasLabel));
    7380:     if (hasLabel) {
    7381:       *pnext = link->next; /* Remove from list */
    7382:       PetscCall(PetscStrcmp(name, "depth", &hasLabel));
    7383:       if (hasLabel) dm->depthLabel = NULL;
    7384:       PetscCall(PetscStrcmp(name, "celltype", &hasLabel));
    7385:       if (hasLabel) dm->celltypeLabel = NULL;
    7386:       if (label) *label = link->label;
    7387:       else PetscCall(DMLabelDestroy(&link->label));
    7388:       PetscCall(PetscFree(link));
    7389:       break;
    7390:     }
    7391:   }
    7392:   PetscFunctionReturn(PETSC_SUCCESS);
    7393: }

    7395: /*@
    7396:   DMRemoveLabelBySelf - Remove the label from this `DM`

    7398:   Not Collective

    7400:   Input Parameters:
    7401: + dm           - The `DM` object
    7402: . label        - The `DMLabel` to be removed from the `DM`
    7403: - failNotFound - Should it fail if the label is not found in the `DM`?

    7405:   Level: developer

    7407:   Note:
    7408:   Only exactly the same instance is removed if found, name match is ignored.
    7409:   If the `DM` has an exclusive reference to the label, the label gets destroyed and
    7410:   *label nullified.

    7412: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabel()` `DMGetLabelValue()`, `DMSetLabelValue()`, `DMLabelDestroy()`, `DMRemoveLabel()`
    7413: @*/
    7414: PetscErrorCode DMRemoveLabelBySelf(DM dm, DMLabel *label, PetscBool failNotFound)
    7415: {
    7416:   DMLabelLink link, *pnext;
    7417:   PetscBool   hasLabel = PETSC_FALSE;

    7419:   PetscFunctionBegin;
    7421:   PetscAssertPointer(label, 2);
    7422:   if (!*label && !failNotFound) PetscFunctionReturn(PETSC_SUCCESS);
    7425:   for (pnext = &dm->labels; (link = *pnext); pnext = &link->next) {
    7426:     if (*label == link->label) {
    7427:       hasLabel = PETSC_TRUE;
    7428:       *pnext   = link->next; /* Remove from list */
    7429:       if (*label == dm->depthLabel) dm->depthLabel = NULL;
    7430:       if (*label == dm->celltypeLabel) dm->celltypeLabel = NULL;
    7431:       if (((PetscObject)link->label)->refct < 2) *label = NULL; /* nullify if exclusive reference */
    7432:       PetscCall(DMLabelDestroy(&link->label));
    7433:       PetscCall(PetscFree(link));
    7434:       break;
    7435:     }
    7436:   }
    7437:   PetscCheck(hasLabel || !failNotFound, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Given label not found in DM");
    7438:   PetscFunctionReturn(PETSC_SUCCESS);
    7439: }

    7441: /*@
    7442:   DMGetLabelOutput - Get the output flag for a given label

    7444:   Not Collective

    7446:   Input Parameters:
    7447: + dm   - The `DM` object
    7448: - name - The label name

    7450:   Output Parameter:
    7451: . output - The flag for output

    7453:   Level: developer

    7455: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMSetLabelOutput()`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7456: @*/
    7457: PetscErrorCode DMGetLabelOutput(DM dm, const char name[], PetscBool *output)
    7458: {
    7459:   DMLabelLink next = dm->labels;
    7460:   const char *lname;

    7462:   PetscFunctionBegin;
    7464:   PetscAssertPointer(name, 2);
    7465:   PetscAssertPointer(output, 3);
    7466:   while (next) {
    7467:     PetscBool flg;

    7469:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7470:     PetscCall(PetscStrcmp(name, lname, &flg));
    7471:     if (flg) {
    7472:       *output = next->output;
    7473:       PetscFunctionReturn(PETSC_SUCCESS);
    7474:     }
    7475:     next = next->next;
    7476:   }
    7477:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "No label named %s was present in this dm", name);
    7478: }

    7480: /*@
    7481:   DMSetLabelOutput - Set if a given label should be saved to a `PetscViewer` in calls to `DMView()`

    7483:   Not Collective

    7485:   Input Parameters:
    7486: + dm     - The `DM` object
    7487: . name   - The label name
    7488: - output - `PETSC_TRUE` to save the label to the viewer

    7490:   Level: developer

    7492: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMGetOutputFlag()`, `DMGetLabelOutput()`, `DMCreateLabel()`, `DMHasLabel()`, `DMGetLabelValue()`, `DMSetLabelValue()`, `DMGetStratumIS()`
    7493: @*/
    7494: PetscErrorCode DMSetLabelOutput(DM dm, const char name[], PetscBool output)
    7495: {
    7496:   DMLabelLink next = dm->labels;
    7497:   const char *lname;

    7499:   PetscFunctionBegin;
    7501:   PetscAssertPointer(name, 2);
    7502:   while (next) {
    7503:     PetscBool flg;

    7505:     PetscCall(PetscObjectGetName((PetscObject)next->label, &lname));
    7506:     PetscCall(PetscStrcmp(name, lname, &flg));
    7507:     if (flg) {
    7508:       next->output = output;
    7509:       PetscFunctionReturn(PETSC_SUCCESS);
    7510:     }
    7511:     next = next->next;
    7512:   }
    7513:   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "No label named %s was present in this dm", name);
    7514: }

    7516: /*@
    7517:   DMCopyLabels - Copy labels from one `DM` mesh to another `DM` with a superset of the points

    7519:   Collective

    7521:   Input Parameters:
    7522: + dmA   - The `DM` object with initial labels
    7523: . dmB   - The `DM` object to which labels are copied
    7524: . mode  - Copy labels by pointers (`PETSC_OWN_POINTER`) or duplicate them (`PETSC_COPY_VALUES`)
    7525: . all   - Copy all labels including "depth", "dim", and "celltype" (`PETSC_TRUE`) which are otherwise ignored (`PETSC_FALSE`)
    7526: - emode - How to behave when a `DMLabel` in the source and destination `DM`s with the same name is encountered (see `DMCopyLabelsMode`)

    7528:   Level: intermediate

    7530:   Note:
    7531:   This is typically used when interpolating or otherwise adding to a mesh, or testing.

    7533: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMAddLabel()`, `DMCopyLabelsMode`
    7534: @*/
    7535: PetscErrorCode DMCopyLabels(DM dmA, DM dmB, PetscCopyMode mode, PetscBool all, DMCopyLabelsMode emode)
    7536: {
    7537:   DMLabel     label, labelNew, labelOld;
    7538:   const char *name;
    7539:   PetscBool   flg;
    7540:   DMLabelLink link;

    7542:   PetscFunctionBegin;
    7547:   PetscCheck(mode != PETSC_USE_POINTER, PetscObjectComm((PetscObject)dmA), PETSC_ERR_SUP, "PETSC_USE_POINTER not supported for objects");
    7548:   if (dmA == dmB) PetscFunctionReturn(PETSC_SUCCESS);
    7549:   for (link = dmA->labels; link; link = link->next) {
    7550:     label = link->label;
    7551:     PetscCall(PetscObjectGetName((PetscObject)label, &name));
    7552:     if (!all) {
    7553:       PetscCall(PetscStrcmp(name, "depth", &flg));
    7554:       if (flg) continue;
    7555:       PetscCall(PetscStrcmp(name, "dim", &flg));
    7556:       if (flg) continue;
    7557:       PetscCall(PetscStrcmp(name, "celltype", &flg));
    7558:       if (flg) continue;
    7559:     }
    7560:     PetscCall(DMGetLabel(dmB, name, &labelOld));
    7561:     if (labelOld) {
    7562:       switch (emode) {
    7563:       case DM_COPY_LABELS_KEEP:
    7564:         continue;
    7565:       case DM_COPY_LABELS_REPLACE:
    7566:         PetscCall(DMRemoveLabelBySelf(dmB, &labelOld, PETSC_TRUE));
    7567:         break;
    7568:       case DM_COPY_LABELS_FAIL:
    7569:         SETERRQ(PetscObjectComm((PetscObject)dmA), PETSC_ERR_ARG_OUTOFRANGE, "Label %s already exists in destination DM", name);
    7570:       default:
    7571:         SETERRQ(PetscObjectComm((PetscObject)dmA), PETSC_ERR_ARG_OUTOFRANGE, "Unhandled DMCopyLabelsMode %d", (int)emode);
    7572:       }
    7573:     }
    7574:     if (mode == PETSC_COPY_VALUES) {
    7575:       PetscCall(DMLabelDuplicate(label, &labelNew));
    7576:     } else {
    7577:       labelNew = label;
    7578:     }
    7579:     PetscCall(DMAddLabel(dmB, labelNew));
    7580:     if (mode == PETSC_COPY_VALUES) PetscCall(DMLabelDestroy(&labelNew));
    7581:   }
    7582:   PetscFunctionReturn(PETSC_SUCCESS);
    7583: }

    7585: /*@C
    7586:   DMCompareLabels - Compare labels between two `DM` objects

    7588:   Collective; No Fortran Support

    7590:   Input Parameters:
    7591: + dm0 - First `DM` object
    7592: - dm1 - Second `DM` object

    7594:   Output Parameters:
    7595: + equal   - (Optional) Flag whether labels of `dm0` and `dm1` are the same
    7596: - message - (Optional) Message describing the difference, or `NULL` if there is no difference

    7598:   Level: intermediate

    7600:   Notes:
    7601:   The output flag equal will be the same on all processes.

    7603:   If equal is passed as `NULL` and difference is found, an error is thrown on all processes.

    7605:   Make sure to pass equal is `NULL` on all processes or none of them.

    7607:   The output message is set independently on each rank.

    7609:   message must be freed with `PetscFree()`

    7611:   If message is passed as `NULL` and a difference is found, the difference description is printed to `stderr` in synchronized manner.

    7613:   Make sure to pass message as `NULL` on all processes or no processes.

    7615:   Labels are matched by name. If the number of labels and their names are equal,
    7616:   `DMLabelCompare()` is used to compare each pair of labels with the same name.

    7618:   Developer Note:
    7619:   Cannot automatically generate the Fortran stub because `message` must be freed with `PetscFree()`

    7621: .seealso: [](ch_dmbase), `DM`, `DMLabel`, `DMAddLabel()`, `DMCopyLabelsMode`, `DMLabelCompare()`
    7622: @*/
    7623: PetscErrorCode DMCompareLabels(DM dm0, DM dm1, PetscBool *equal, char *message[]) PeNS
    7624: {
    7625:   PetscInt    n, i;
    7626:   char        msg[PETSC_MAX_PATH_LEN] = "";
    7627:   PetscBool   eq;
    7628:   MPI_Comm    comm;
    7629:   PetscMPIInt rank;

    7631:   PetscFunctionBegin;
    7634:   PetscCheckSameComm(dm0, 1, dm1, 2);
    7635:   if (equal) PetscAssertPointer(equal, 3);
    7636:   if (message) PetscAssertPointer(message, 4);
    7637:   PetscCall(PetscObjectGetComm((PetscObject)dm0, &comm));
    7638:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
    7639:   {
    7640:     PetscInt n1;

    7642:     PetscCall(DMGetNumLabels(dm0, &n));
    7643:     PetscCall(DMGetNumLabels(dm1, &n1));
    7644:     eq = (PetscBool)(n == n1);
    7645:     if (!eq) PetscCall(PetscSNPrintf(msg, sizeof(msg), "Number of labels in dm0 = %" PetscInt_FMT " != %" PetscInt_FMT " = Number of labels in dm1", n, n1));
    7646:     PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &eq, 1, MPIU_BOOL, MPI_LAND, comm));
    7647:     if (!eq) goto finish;
    7648:   }
    7649:   for (i = 0; i < n; i++) {
    7650:     DMLabel     l0, l1;
    7651:     const char *name;
    7652:     char       *msgInner;

    7654:     /* Ignore label order */
    7655:     PetscCall(DMGetLabelByNum(dm0, i, &l0));
    7656:     PetscCall(PetscObjectGetName((PetscObject)l0, &name));
    7657:     PetscCall(DMGetLabel(dm1, name, &l1));
    7658:     if (!l1) {
    7659:       PetscCall(PetscSNPrintf(msg, sizeof(msg), "Label \"%s\" (#%" PetscInt_FMT " in dm0) not found in dm1", name, i));
    7660:       eq = PETSC_FALSE;
    7661:       break;
    7662:     }
    7663:     PetscCall(DMLabelCompare(comm, l0, l1, &eq, &msgInner));
    7664:     PetscCall(PetscStrncpy(msg, msgInner, sizeof(msg)));
    7665:     PetscCall(PetscFree(msgInner));
    7666:     if (!eq) break;
    7667:   }
    7668:   PetscCallMPI(MPIU_Allreduce(MPI_IN_PLACE, &eq, 1, MPIU_BOOL, MPI_LAND, comm));
    7669: finish:
    7670:   /* If message output arg not set, print to stderr */
    7671:   if (message) {
    7672:     *message = NULL;
    7673:     if (msg[0]) PetscCall(PetscStrallocpy(msg, message));
    7674:   } else {
    7675:     if (msg[0]) PetscCall(PetscSynchronizedFPrintf(comm, PETSC_STDERR, "[%d] %s\n", rank, msg));
    7676:     PetscCall(PetscSynchronizedFlush(comm, PETSC_STDERR));
    7677:   }
    7678:   /* If same output arg not ser and labels are not equal, throw error */
    7679:   if (equal) *equal = eq;
    7680:   else PetscCheck(eq, comm, PETSC_ERR_ARG_INCOMP, "DMLabels are not the same in dm0 and dm1");
    7681:   PetscFunctionReturn(PETSC_SUCCESS);
    7682: }

    7684: PetscErrorCode DMSetLabelValue_Fast(DM dm, DMLabel *label, const char name[], PetscInt point, PetscInt value)
    7685: {
    7686:   PetscFunctionBegin;
    7687:   PetscAssertPointer(label, 2);
    7688:   if (!*label) {
    7689:     PetscCall(DMCreateLabel(dm, name));
    7690:     PetscCall(DMGetLabel(dm, name, label));
    7691:   }
    7692:   PetscCall(DMLabelSetValue(*label, point, value));
    7693:   PetscFunctionReturn(PETSC_SUCCESS);
    7694: }

    7696: /*
    7697:   Many mesh programs, such as Triangle and TetGen, allow only a single label for each mesh point. Therefore, we would
    7698:   like to encode all label IDs using a single, universal label. We can do this by assigning an integer to every
    7699:   (label, id) pair in the DM.

    7701:   However, a mesh point can have multiple labels, so we must separate all these values. We will assign a bit range to
    7702:   each label.
    7703: */
    7704: PetscErrorCode DMUniversalLabelCreate(DM dm, DMUniversalLabel *universal)
    7705: {
    7706:   DMUniversalLabel ul;
    7707:   PetscBool       *active;
    7708:   PetscInt         pStart, pEnd, p, Nl, l, m;

    7710:   PetscFunctionBegin;
    7711:   PetscCall(PetscMalloc1(1, &ul));
    7712:   PetscCall(DMLabelCreate(PETSC_COMM_SELF, "universal", &ul->label));
    7713:   PetscCall(DMGetNumLabels(dm, &Nl));
    7714:   PetscCall(PetscCalloc1(Nl, &active));
    7715:   ul->Nl = 0;
    7716:   for (l = 0; l < Nl; ++l) {
    7717:     PetscBool   isdepth, iscelltype;
    7718:     const char *name;

    7720:     PetscCall(DMGetLabelName(dm, l, &name));
    7721:     PetscCall(PetscStrncmp(name, "depth", 6, &isdepth));
    7722:     PetscCall(PetscStrncmp(name, "celltype", 9, &iscelltype));
    7723:     active[l] = !(isdepth || iscelltype) ? PETSC_TRUE : PETSC_FALSE;
    7724:     if (active[l]) ++ul->Nl;
    7725:   }
    7726:   PetscCall(PetscCalloc5(ul->Nl, &ul->names, ul->Nl, &ul->indices, ul->Nl + 1, &ul->offsets, ul->Nl + 1, &ul->bits, ul->Nl, &ul->masks));
    7727:   ul->Nv = 0;
    7728:   for (l = 0, m = 0; l < Nl; ++l) {
    7729:     DMLabel     label;
    7730:     PetscInt    nv;
    7731:     const char *name;

    7733:     if (!active[l]) continue;
    7734:     PetscCall(DMGetLabelName(dm, l, &name));
    7735:     PetscCall(DMGetLabelByNum(dm, l, &label));
    7736:     PetscCall(DMLabelGetNumValues(label, &nv));
    7737:     PetscCall(PetscStrallocpy(name, &ul->names[m]));
    7738:     ul->indices[m] = l;
    7739:     ul->Nv += nv;
    7740:     ul->offsets[m + 1] = nv;
    7741:     ul->bits[m + 1]    = PetscCeilReal(PetscLog2Real(nv + 1));
    7742:     ++m;
    7743:   }
    7744:   for (l = 1; l <= ul->Nl; ++l) {
    7745:     ul->offsets[l] = ul->offsets[l - 1] + ul->offsets[l];
    7746:     ul->bits[l]    = ul->bits[l - 1] + ul->bits[l];
    7747:   }
    7748:   for (l = 0; l < ul->Nl; ++l) {
    7749:     PetscInt b;

    7751:     ul->masks[l] = 0;
    7752:     for (b = ul->bits[l]; b < ul->bits[l + 1]; ++b) ul->masks[l] |= 1 << b;
    7753:   }
    7754:   PetscCall(PetscMalloc1(ul->Nv, &ul->values));
    7755:   for (l = 0, m = 0; l < Nl; ++l) {
    7756:     DMLabel         label;
    7757:     IS              valueIS;
    7758:     const PetscInt *varr;
    7759:     PetscInt        nv, v;

    7761:     if (!active[l]) continue;
    7762:     PetscCall(DMGetLabelByNum(dm, l, &label));
    7763:     PetscCall(DMLabelGetNumValues(label, &nv));
    7764:     PetscCall(DMLabelGetValueIS(label, &valueIS));
    7765:     PetscCall(ISGetIndices(valueIS, &varr));
    7766:     for (v = 0; v < nv; ++v) ul->values[ul->offsets[m] + v] = varr[v];
    7767:     PetscCall(ISRestoreIndices(valueIS, &varr));
    7768:     PetscCall(ISDestroy(&valueIS));
    7769:     PetscCall(PetscSortInt(nv, &ul->values[ul->offsets[m]]));
    7770:     ++m;
    7771:   }
    7772:   PetscCall(DMPlexGetChart(dm, &pStart, &pEnd));
    7773:   for (p = pStart; p < pEnd; ++p) {
    7774:     PetscInt  uval   = 0;
    7775:     PetscBool marked = PETSC_FALSE;

    7777:     for (l = 0, m = 0; l < Nl; ++l) {
    7778:       DMLabel  label;
    7779:       PetscInt val, defval, loc, nv;

    7781:       if (!active[l]) continue;
    7782:       PetscCall(DMGetLabelByNum(dm, l, &label));
    7783:       PetscCall(DMLabelGetValue(label, p, &val));
    7784:       PetscCall(DMLabelGetDefaultValue(label, &defval));
    7785:       if (val == defval) {
    7786:         ++m;
    7787:         continue;
    7788:       }
    7789:       nv     = ul->offsets[m + 1] - ul->offsets[m];
    7790:       marked = PETSC_TRUE;
    7791:       PetscCall(PetscFindInt(val, nv, &ul->values[ul->offsets[m]], &loc));
    7792:       PetscCheck(loc >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Label value %" PetscInt_FMT " not found in compression array", val);
    7793:       uval += (loc + 1) << ul->bits[m];
    7794:       ++m;
    7795:     }
    7796:     if (marked) PetscCall(DMLabelSetValue(ul->label, p, uval));
    7797:   }
    7798:   PetscCall(PetscFree(active));
    7799:   *universal = ul;
    7800:   PetscFunctionReturn(PETSC_SUCCESS);
    7801: }

    7803: PetscErrorCode DMUniversalLabelDestroy(DMUniversalLabel *universal)
    7804: {
    7805:   PetscInt l;

    7807:   PetscFunctionBegin;
    7808:   for (l = 0; l < (*universal)->Nl; ++l) PetscCall(PetscFree((*universal)->names[l]));
    7809:   PetscCall(DMLabelDestroy(&(*universal)->label));
    7810:   PetscCall(PetscFree5((*universal)->names, (*universal)->indices, (*universal)->offsets, (*universal)->bits, (*universal)->masks));
    7811:   PetscCall(PetscFree((*universal)->values));
    7812:   PetscCall(PetscFree(*universal));
    7813:   *universal = NULL;
    7814:   PetscFunctionReturn(PETSC_SUCCESS);
    7815: }

    7817: PetscErrorCode DMUniversalLabelGetLabel(DMUniversalLabel ul, DMLabel *ulabel)
    7818: {
    7819:   PetscFunctionBegin;
    7820:   PetscAssertPointer(ulabel, 2);
    7821:   *ulabel = ul->label;
    7822:   PetscFunctionReturn(PETSC_SUCCESS);
    7823: }

    7825: PetscErrorCode DMUniversalLabelCreateLabels(DMUniversalLabel ul, PetscBool preserveOrder, DM dm)
    7826: {
    7827:   PetscInt Nl = ul->Nl, l;

    7829:   PetscFunctionBegin;
    7831:   for (l = 0; l < Nl; ++l) {
    7832:     if (preserveOrder) PetscCall(DMCreateLabelAtIndex(dm, ul->indices[l], ul->names[l]));
    7833:     else PetscCall(DMCreateLabel(dm, ul->names[l]));
    7834:   }
    7835:   if (preserveOrder) {
    7836:     for (l = 0; l < ul->Nl; ++l) {
    7837:       const char *name;
    7838:       PetscBool   match;

    7840:       PetscCall(DMGetLabelName(dm, ul->indices[l], &name));
    7841:       PetscCall(PetscStrcmp(name, ul->names[l], &match));
    7842:       PetscCheck(match, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Label %" PetscInt_FMT " name %s does not match new name %s", l, name, ul->names[l]);
    7843:     }
    7844:   }
    7845:   PetscFunctionReturn(PETSC_SUCCESS);
    7846: }

    7848: PetscErrorCode DMUniversalLabelSetLabelValue(DMUniversalLabel ul, DM dm, PetscBool useIndex, PetscInt p, PetscInt value)
    7849: {
    7850:   PetscInt l;

    7852:   PetscFunctionBegin;
    7853:   for (l = 0; l < ul->Nl; ++l) {
    7854:     DMLabel  label;
    7855:     PetscInt lval = (value & ul->masks[l]) >> ul->bits[l];

    7857:     if (lval) {
    7858:       if (useIndex) PetscCall(DMGetLabelByNum(dm, ul->indices[l], &label));
    7859:       else PetscCall(DMGetLabel(dm, ul->names[l], &label));
    7860:       PetscCall(DMLabelSetValue(label, p, ul->values[ul->offsets[l] + lval - 1]));
    7861:     }
    7862:   }
    7863:   PetscFunctionReturn(PETSC_SUCCESS);
    7864: }

    7866: /*@
    7867:   DMGetCoarseDM - Get the coarse `DM`from which this `DM` was obtained by refinement

    7869:   Not Collective

    7871:   Input Parameter:
    7872: . dm - The `DM` object

    7874:   Output Parameter:
    7875: . cdm - The coarse `DM`

    7877:   Level: intermediate

    7879: .seealso: [](ch_dmbase), `DM`, `DMSetCoarseDM()`, `DMCoarsen()`
    7880: @*/
    7881: PetscErrorCode DMGetCoarseDM(DM dm, DM *cdm)
    7882: {
    7883:   PetscFunctionBegin;
    7885:   PetscAssertPointer(cdm, 2);
    7886:   *cdm = dm->coarseMesh;
    7887:   PetscFunctionReturn(PETSC_SUCCESS);
    7888: }

    7890: /*@
    7891:   DMSetCoarseDM - Set the coarse `DM` from which this `DM` was obtained by refinement

    7893:   Input Parameters:
    7894: + dm  - The `DM` object
    7895: - cdm - The coarse `DM`

    7897:   Level: intermediate

    7899:   Note:
    7900:   Normally this is set automatically by `DMRefine()`

    7902: .seealso: [](ch_dmbase), `DM`, `DMGetCoarseDM()`, `DMCoarsen()`, `DMSetRefine()`, `DMSetFineDM()`
    7903: @*/
    7904: PetscErrorCode DMSetCoarseDM(DM dm, DM cdm)
    7905: {
    7906:   PetscFunctionBegin;
    7909:   if (dm == cdm) cdm = NULL;
    7910:   PetscCall(PetscObjectReference((PetscObject)cdm));
    7911:   PetscCall(DMDestroy(&dm->coarseMesh));
    7912:   dm->coarseMesh = cdm;
    7913:   PetscFunctionReturn(PETSC_SUCCESS);
    7914: }

    7916: /*@
    7917:   DMGetFineDM - Get the fine mesh from which this `DM` was obtained by coarsening

    7919:   Input Parameter:
    7920: . dm - The `DM` object

    7922:   Output Parameter:
    7923: . fdm - The fine `DM`

    7925:   Level: intermediate

    7927: .seealso: [](ch_dmbase), `DM`, `DMSetFineDM()`, `DMCoarsen()`, `DMRefine()`
    7928: @*/
    7929: PetscErrorCode DMGetFineDM(DM dm, DM *fdm)
    7930: {
    7931:   PetscFunctionBegin;
    7933:   PetscAssertPointer(fdm, 2);
    7934:   *fdm = dm->fineMesh;
    7935:   PetscFunctionReturn(PETSC_SUCCESS);
    7936: }

    7938: /*@
    7939:   DMSetFineDM - Set the fine mesh from which this was obtained by coarsening

    7941:   Input Parameters:
    7942: + dm  - The `DM` object
    7943: - fdm - The fine `DM`

    7945:   Level: developer

    7947:   Note:
    7948:   Normally this is set automatically by `DMCoarsen()`

    7950: .seealso: [](ch_dmbase), `DM`, `DMGetFineDM()`, `DMCoarsen()`, `DMRefine()`
    7951: @*/
    7952: PetscErrorCode DMSetFineDM(DM dm, DM fdm)
    7953: {
    7954:   PetscFunctionBegin;
    7957:   if (dm == fdm) fdm = NULL;
    7958:   PetscCall(PetscObjectReference((PetscObject)fdm));
    7959:   PetscCall(DMDestroy(&dm->fineMesh));
    7960:   dm->fineMesh = fdm;
    7961:   PetscFunctionReturn(PETSC_SUCCESS);
    7962: }

    7964: /*@C
    7965:   DMAddBoundary - Add a boundary condition to a model represented by a `DM`

    7967:   Collective

    7969:   Input Parameters:
    7970: + dm       - The `DM`, with a `PetscDS` that matches the problem being constrained
    7971: . type     - The type of condition, e.g. `DM_BC_ESSENTIAL_ANALYTIC`, `DM_BC_ESSENTIAL_FIELD` (Dirichlet), or `DM_BC_NATURAL` (Neumann)
    7972: . name     - The BC name
    7973: . label    - The label defining constrained points
    7974: . Nv       - The number of `DMLabel` values for constrained points
    7975: . values   - An array of values for constrained points
    7976: . field    - The field to constrain
    7977: . Nc       - The number of constrained field components (0 will constrain all components)
    7978: . comps    - An array of constrained component numbers
    7979: . bcFunc   - A pointwise function giving boundary values
    7980: . bcFunc_t - A pointwise function giving the time deriative of the boundary values, or NULL
    7981: - ctx      - An optional user context for bcFunc

    7983:   Output Parameter:
    7984: . bd - (Optional) Boundary number

    7986:   Options Database Keys:
    7987: + -bc_<boundary name> <num>      - Overrides the boundary ids
    7988: - -bc_<boundary name>_comp <num> - Overrides the boundary components

    7990:   Level: intermediate

    7992:   Notes:
    7993:   If the `DM` is of type `DMPLEX` and the field is of type `PetscFE`, then this function completes the label using `DMPlexLabelComplete()`.

    7995:   Both bcFunc and bcFunc_t will depend on the boundary condition type. If the type if `DM_BC_ESSENTIAL`, then the calling sequence is\:
    7996: .vb
    7997:  void bcFunc(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar bcval[])
    7998: .ve

    8000:   If the type is `DM_BC_ESSENTIAL_FIELD` or other _FIELD value, then the calling sequence is\:

    8002: .vb
    8003:   void bcFunc(PetscInt dim, PetscInt Nf, PetscInt NfAux,
    8004:               const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[],
    8005:               const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[],
    8006:               PetscReal time, const PetscReal x[], PetscScalar bcval[])
    8007: .ve
    8008: + dim - the spatial dimension
    8009: . Nf - the number of fields
    8010: . uOff - the offset into u[] and u_t[] for each field
    8011: . uOff_x - the offset into u_x[] for each field
    8012: . u - each field evaluated at the current point
    8013: . u_t - the time derivative of each field evaluated at the current point
    8014: . u_x - the gradient of each field evaluated at the current point
    8015: . aOff - the offset into a[] and a_t[] for each auxiliary field
    8016: . aOff_x - the offset into a_x[] for each auxiliary field
    8017: . a - each auxiliary field evaluated at the current point
    8018: . a_t - the time derivative of each auxiliary field evaluated at the current point
    8019: . a_x - the gradient of auxiliary each field evaluated at the current point
    8020: . t - current time
    8021: . x - coordinates of the current point
    8022: . numConstants - number of constant parameters
    8023: . constants - constant parameters
    8024: - bcval - output values at the current point

    8026: .seealso: [](ch_dmbase), `DM`, `DSGetBoundary()`, `PetscDSAddBoundary()`
    8027: @*/
    8028: PetscErrorCode DMAddBoundary(DM dm, DMBoundaryConditionType type, const char name[], DMLabel label, PetscInt Nv, const PetscInt values[], PetscInt field, PetscInt Nc, const PetscInt comps[], void (*bcFunc)(void), void (*bcFunc_t)(void), void *ctx, PetscInt *bd)
    8029: {
    8030:   PetscDS ds;

    8032:   PetscFunctionBegin;
    8039:   PetscCheck(!dm->localSection, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "Cannot add boundary to DM after creating local section");
    8040:   PetscCall(DMGetDS(dm, &ds));
    8041:   /* Complete label */
    8042:   if (label) {
    8043:     PetscObject  obj;
    8044:     PetscClassId id;

    8046:     PetscCall(DMGetField(dm, field, NULL, &obj));
    8047:     PetscCall(PetscObjectGetClassId(obj, &id));
    8048:     if (id == PETSCFE_CLASSID) {
    8049:       DM plex;

    8051:       PetscCall(DMConvert(dm, DMPLEX, &plex));
    8052:       if (plex) PetscCall(DMPlexLabelComplete(plex, label));
    8053:       PetscCall(DMDestroy(&plex));
    8054:     }
    8055:   }
    8056:   PetscCall(PetscDSAddBoundary(ds, type, name, label, Nv, values, field, Nc, comps, bcFunc, bcFunc_t, ctx, bd));
    8057:   PetscFunctionReturn(PETSC_SUCCESS);
    8058: }

    8060: /* TODO Remove this since now the structures are the same */
    8061: static PetscErrorCode DMPopulateBoundary(DM dm)
    8062: {
    8063:   PetscDS     ds;
    8064:   DMBoundary *lastnext;
    8065:   DSBoundary  dsbound;

    8067:   PetscFunctionBegin;
    8068:   PetscCall(DMGetDS(dm, &ds));
    8069:   dsbound = ds->boundary;
    8070:   if (dm->boundary) {
    8071:     DMBoundary next = dm->boundary;

    8073:     /* quick check to see if the PetscDS has changed */
    8074:     if (next->dsboundary == dsbound) PetscFunctionReturn(PETSC_SUCCESS);
    8075:     /* the PetscDS has changed: tear down and rebuild */
    8076:     while (next) {
    8077:       DMBoundary b = next;

    8079:       next = b->next;
    8080:       PetscCall(PetscFree(b));
    8081:     }
    8082:     dm->boundary = NULL;
    8083:   }

    8085:   lastnext = &dm->boundary;
    8086:   while (dsbound) {
    8087:     DMBoundary dmbound;

    8089:     PetscCall(PetscNew(&dmbound));
    8090:     dmbound->dsboundary = dsbound;
    8091:     dmbound->label      = dsbound->label;
    8092:     /* push on the back instead of the front so that it is in the same order as in the PetscDS */
    8093:     *lastnext = dmbound;
    8094:     lastnext  = &dmbound->next;
    8095:     dsbound   = dsbound->next;
    8096:   }
    8097:   PetscFunctionReturn(PETSC_SUCCESS);
    8098: }

    8100: /* TODO: missing manual page */
    8101: PetscErrorCode DMIsBoundaryPoint(DM dm, PetscInt point, PetscBool *isBd)
    8102: {
    8103:   DMBoundary b;

    8105:   PetscFunctionBegin;
    8107:   PetscAssertPointer(isBd, 3);
    8108:   *isBd = PETSC_FALSE;
    8109:   PetscCall(DMPopulateBoundary(dm));
    8110:   b = dm->boundary;
    8111:   while (b && !*isBd) {
    8112:     DMLabel    label = b->label;
    8113:     DSBoundary dsb   = b->dsboundary;
    8114:     PetscInt   i;

    8116:     if (label) {
    8117:       for (i = 0; i < dsb->Nv && !*isBd; ++i) PetscCall(DMLabelStratumHasPoint(label, dsb->values[i], point, isBd));
    8118:     }
    8119:     b = b->next;
    8120:   }
    8121:   PetscFunctionReturn(PETSC_SUCCESS);
    8122: }

    8124: /*@C
    8125:   DMProjectFunction - This projects the given function into the function space provided by a `DM`, putting the coefficients in a global vector.

    8127:   Collective

    8129:   Input Parameters:
    8130: + dm    - The `DM`
    8131: . time  - The time
    8132: . funcs - The coordinate functions to evaluate, one per field
    8133: . ctxs  - Optional array of contexts to pass to each coordinate function.  ctxs itself may be null.
    8134: - mode  - The insertion mode for values

    8136:   Output Parameter:
    8137: . X - vector

    8139:   Calling sequence of `funcs`:
    8140: + dim  - The spatial dimension
    8141: . time - The time at which to sample
    8142: . x    - The coordinates
    8143: . Nc   - The number of components
    8144: . u    - The output field values
    8145: - ctx  - optional user-defined function context

    8147:   Level: developer

    8149:   Developer Notes:
    8150:   This API is specific to only particular usage of `DM`

    8152:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8154: .seealso: [](ch_dmbase), `DM`, `DMProjectFunctionLocal()`, `DMProjectFunctionLabel()`, `DMComputeL2Diff()`
    8155: @*/
    8156: PetscErrorCode DMProjectFunction(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, void *ctx), void **ctxs, InsertMode mode, Vec X)
    8157: {
    8158:   Vec localX;

    8160:   PetscFunctionBegin;
    8162:   PetscCall(PetscLogEventBegin(DM_ProjectFunction, dm, X, 0, 0));
    8163:   PetscCall(DMGetLocalVector(dm, &localX));
    8164:   PetscCall(VecSet(localX, 0.));
    8165:   PetscCall(DMProjectFunctionLocal(dm, time, funcs, ctxs, mode, localX));
    8166:   PetscCall(DMLocalToGlobalBegin(dm, localX, mode, X));
    8167:   PetscCall(DMLocalToGlobalEnd(dm, localX, mode, X));
    8168:   PetscCall(DMRestoreLocalVector(dm, &localX));
    8169:   PetscCall(PetscLogEventEnd(DM_ProjectFunction, dm, X, 0, 0));
    8170:   PetscFunctionReturn(PETSC_SUCCESS);
    8171: }

    8173: /*@C
    8174:   DMProjectFunctionLocal - This projects the given function into the function space provided by a `DM`, putting the coefficients in a local vector.

    8176:   Not Collective

    8178:   Input Parameters:
    8179: + dm    - The `DM`
    8180: . time  - The time
    8181: . funcs - The coordinate functions to evaluate, one per field
    8182: . ctxs  - Optional array of contexts to pass to each coordinate function.  ctxs itself may be null.
    8183: - mode  - The insertion mode for values

    8185:   Output Parameter:
    8186: . localX - vector

    8188:   Calling sequence of `funcs`:
    8189: + dim  - The spatial dimension
    8190: . time - The current timestep
    8191: . x    - The coordinates
    8192: . Nc   - The number of components
    8193: . u    - The output field values
    8194: - ctx  - optional user-defined function context

    8196:   Level: developer

    8198:   Developer Notes:
    8199:   This API is specific to only particular usage of `DM`

    8201:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8203: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMProjectFunctionLabel()`, `DMComputeL2Diff()`
    8204: @*/
    8205: PetscErrorCode DMProjectFunctionLocal(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, void *ctx), void **ctxs, InsertMode mode, Vec localX)
    8206: {
    8207:   PetscFunctionBegin;
    8210:   PetscUseTypeMethod(dm, projectfunctionlocal, time, funcs, ctxs, mode, localX);
    8211:   PetscFunctionReturn(PETSC_SUCCESS);
    8212: }

    8214: /*@C
    8215:   DMProjectFunctionLabel - This projects the given function into the function space provided by the `DM`, putting the coefficients in a global vector, setting values only for points in the given label.

    8217:   Collective

    8219:   Input Parameters:
    8220: + dm     - The `DM`
    8221: . time   - The time
    8222: . numIds - The number of ids
    8223: . ids    - The ids
    8224: . Nc     - The number of components
    8225: . comps  - The components
    8226: . label  - The `DMLabel` selecting the portion of the mesh for projection
    8227: . funcs  - The coordinate functions to evaluate, one per field
    8228: . ctxs   - Optional array of contexts to pass to each coordinate function.  ctxs may be null.
    8229: - mode   - The insertion mode for values

    8231:   Output Parameter:
    8232: . X - vector

    8234:   Calling sequence of `funcs`:
    8235: + dim  - The spatial dimension
    8236: . time - The current timestep
    8237: . x    - The coordinates
    8238: . Nc   - The number of components
    8239: . u    - The output field values
    8240: - ctx  - optional user-defined function context

    8242:   Level: developer

    8244:   Developer Notes:
    8245:   This API is specific to only particular usage of `DM`

    8247:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8249: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMProjectFunctionLocal()`, `DMProjectFunctionLabelLocal()`, `DMComputeL2Diff()`
    8250: @*/
    8251: PetscErrorCode DMProjectFunctionLabel(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, void *ctx), void **ctxs, InsertMode mode, Vec X)
    8252: {
    8253:   Vec localX;

    8255:   PetscFunctionBegin;
    8257:   PetscCall(DMGetLocalVector(dm, &localX));
    8258:   PetscCall(VecSet(localX, 0.));
    8259:   PetscCall(DMProjectFunctionLabelLocal(dm, time, label, numIds, ids, Nc, comps, funcs, ctxs, mode, localX));
    8260:   PetscCall(DMLocalToGlobalBegin(dm, localX, mode, X));
    8261:   PetscCall(DMLocalToGlobalEnd(dm, localX, mode, X));
    8262:   PetscCall(DMRestoreLocalVector(dm, &localX));
    8263:   PetscFunctionReturn(PETSC_SUCCESS);
    8264: }

    8266: /*@C
    8267:   DMProjectFunctionLabelLocal - This projects the given function into the function space provided by the `DM`, putting the coefficients in a local vector, setting values only for points in the given label.

    8269:   Not Collective

    8271:   Input Parameters:
    8272: + dm     - The `DM`
    8273: . time   - The time
    8274: . label  - The `DMLabel` selecting the portion of the mesh for projection
    8275: . numIds - The number of ids
    8276: . ids    - The ids
    8277: . Nc     - The number of components
    8278: . comps  - The components
    8279: . funcs  - The coordinate functions to evaluate, one per field
    8280: . ctxs   - Optional array of contexts to pass to each coordinate function.  ctxs itself may be null.
    8281: - mode   - The insertion mode for values

    8283:   Output Parameter:
    8284: . localX - vector

    8286:   Calling sequence of `funcs`:
    8287: + dim  - The spatial dimension
    8288: . time - The current time
    8289: . x    - The coordinates
    8290: . Nc   - The number of components
    8291: . u    - The output field values
    8292: - ctx  - optional user-defined function context

    8294:   Level: developer

    8296:   Developer Notes:
    8297:   This API is specific to only particular usage of `DM`

    8299:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8301: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMProjectFunctionLocal()`, `DMProjectFunctionLabel()`, `DMComputeL2Diff()`
    8302: @*/
    8303: PetscErrorCode DMProjectFunctionLabelLocal(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], PetscErrorCode (**funcs)(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt Nc, PetscScalar *u, void *ctx), void **ctxs, InsertMode mode, Vec localX)
    8304: {
    8305:   PetscFunctionBegin;
    8308:   PetscUseTypeMethod(dm, projectfunctionlabellocal, time, label, numIds, ids, Nc, comps, funcs, ctxs, mode, localX);
    8309:   PetscFunctionReturn(PETSC_SUCCESS);
    8310: }

    8312: /*@C
    8313:   DMProjectFieldLocal - This projects the given function of the input fields into the function space provided by the `DM`, putting the coefficients in a local vector.

    8315:   Not Collective

    8317:   Input Parameters:
    8318: + dm     - The `DM`
    8319: . time   - The time
    8320: . localU - The input field vector; may be `NULL` if projection is defined purely by coordinates
    8321: . funcs  - The functions to evaluate, one per field
    8322: - mode   - The insertion mode for values

    8324:   Output Parameter:
    8325: . localX - The output vector

    8327:   Calling sequence of `funcs`:
    8328: + dim          - The spatial dimension
    8329: . Nf           - The number of input fields
    8330: . NfAux        - The number of input auxiliary fields
    8331: . uOff         - The offset of each field in u[]
    8332: . uOff_x       - The offset of each field in u_x[]
    8333: . u            - The field values at this point in space
    8334: . u_t          - The field time derivative at this point in space (or NULL)
    8335: . u_x          - The field derivatives at this point in space
    8336: . aOff         - The offset of each auxiliary field in u[]
    8337: . aOff_x       - The offset of each auxiliary field in u_x[]
    8338: . a            - The auxiliary field values at this point in space
    8339: . a_t          - The auxiliary field time derivative at this point in space (or NULL)
    8340: . a_x          - The auxiliary field derivatives at this point in space
    8341: . t            - The current time
    8342: . x            - The coordinates of this point
    8343: . numConstants - The number of constants
    8344: . constants    - The value of each constant
    8345: - f            - The value of the function at this point in space

    8347:   Level: intermediate

    8349:   Note:
    8350:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8351:   The input `DM`, attached to U, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8352:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8353:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8355:   Developer Notes:
    8356:   This API is specific to only particular usage of `DM`

    8358:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8360: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabelLocal()`,
    8361: `DMProjectFunction()`, `DMComputeL2Diff()`
    8362: @*/
    8363: PetscErrorCode DMProjectFieldLocal(DM dm, PetscReal time, Vec localU, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec localX)
    8364: {
    8365:   PetscFunctionBegin;
    8369:   PetscUseTypeMethod(dm, projectfieldlocal, time, localU, funcs, mode, localX);
    8370:   PetscFunctionReturn(PETSC_SUCCESS);
    8371: }

    8373: /*@C
    8374:   DMProjectFieldLabelLocal - This projects the given function of the input fields into the function space provided, putting the coefficients in a local vector, calculating only over the portion of the domain specified by the label.

    8376:   Not Collective

    8378:   Input Parameters:
    8379: + dm     - The `DM`
    8380: . time   - The time
    8381: . label  - The `DMLabel` marking the portion of the domain to output
    8382: . numIds - The number of label ids to use
    8383: . ids    - The label ids to use for marking
    8384: . Nc     - The number of components to set in the output, or `PETSC_DETERMINE` for all components
    8385: . comps  - The components to set in the output, or `NULL` for all components
    8386: . localU - The input field vector
    8387: . funcs  - The functions to evaluate, one per field
    8388: - mode   - The insertion mode for values

    8390:   Output Parameter:
    8391: . localX - The output vector

    8393:   Calling sequence of `funcs`:
    8394: + dim          - The spatial dimension
    8395: . Nf           - The number of input fields
    8396: . NfAux        - The number of input auxiliary fields
    8397: . uOff         - The offset of each field in u[]
    8398: . uOff_x       - The offset of each field in u_x[]
    8399: . u            - The field values at this point in space
    8400: . u_t          - The field time derivative at this point in space (or NULL)
    8401: . u_x          - The field derivatives at this point in space
    8402: . aOff         - The offset of each auxiliary field in u[]
    8403: . aOff_x       - The offset of each auxiliary field in u_x[]
    8404: . a            - The auxiliary field values at this point in space
    8405: . a_t          - The auxiliary field time derivative at this point in space (or NULL)
    8406: . a_x          - The auxiliary field derivatives at this point in space
    8407: . t            - The current time
    8408: . x            - The coordinates of this point
    8409: . numConstants - The number of constants
    8410: . constants    - The value of each constant
    8411: - f            - The value of the function at this point in space

    8413:   Level: intermediate

    8415:   Note:
    8416:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8417:   The input `DM`, attached to localU, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8418:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8419:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8421:   Developer Notes:
    8422:   This API is specific to only particular usage of `DM`

    8424:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8426: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabel()`, `DMProjectFunction()`, `DMComputeL2Diff()`
    8427: @*/
    8428: PetscErrorCode DMProjectFieldLabelLocal(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], Vec localU, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec localX)
    8429: {
    8430:   PetscFunctionBegin;
    8434:   PetscUseTypeMethod(dm, projectfieldlabellocal, time, label, numIds, ids, Nc, comps, localU, funcs, mode, localX);
    8435:   PetscFunctionReturn(PETSC_SUCCESS);
    8436: }

    8438: /*@C
    8439:   DMProjectFieldLabel - This projects the given function of the input fields into the function space provided, putting the coefficients in a global vector, calculating only over the portion of the domain specified by the label.

    8441:   Not Collective

    8443:   Input Parameters:
    8444: + dm     - The `DM`
    8445: . time   - The time
    8446: . label  - The `DMLabel` marking the portion of the domain to output
    8447: . numIds - The number of label ids to use
    8448: . ids    - The label ids to use for marking
    8449: . Nc     - The number of components to set in the output, or `PETSC_DETERMINE` for all components
    8450: . comps  - The components to set in the output, or `NULL` for all components
    8451: . U      - The input field vector
    8452: . funcs  - The functions to evaluate, one per field
    8453: - mode   - The insertion mode for values

    8455:   Output Parameter:
    8456: . X - The output vector

    8458:   Calling sequence of `funcs`:
    8459: + dim          - The spatial dimension
    8460: . Nf           - The number of input fields
    8461: . NfAux        - The number of input auxiliary fields
    8462: . uOff         - The offset of each field in u[]
    8463: . uOff_x       - The offset of each field in u_x[]
    8464: . u            - The field values at this point in space
    8465: . u_t          - The field time derivative at this point in space (or NULL)
    8466: . u_x          - The field derivatives at this point in space
    8467: . aOff         - The offset of each auxiliary field in u[]
    8468: . aOff_x       - The offset of each auxiliary field in u_x[]
    8469: . a            - The auxiliary field values at this point in space
    8470: . a_t          - The auxiliary field time derivative at this point in space (or NULL)
    8471: . a_x          - The auxiliary field derivatives at this point in space
    8472: . t            - The current time
    8473: . x            - The coordinates of this point
    8474: . numConstants - The number of constants
    8475: . constants    - The value of each constant
    8476: - f            - The value of the function at this point in space

    8478:   Level: intermediate

    8480:   Note:
    8481:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8482:   The input `DM`, attached to U, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8483:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8484:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8486:   Developer Notes:
    8487:   This API is specific to only particular usage of `DM`

    8489:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8491: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabelLocal()`, `DMProjectFunction()`, `DMComputeL2Diff()`
    8492: @*/
    8493: PetscErrorCode DMProjectFieldLabel(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], Vec U, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec X)
    8494: {
    8495:   DM  dmIn;
    8496:   Vec localU, localX;

    8498:   PetscFunctionBegin;
    8500:   PetscCall(VecGetDM(U, &dmIn));
    8501:   PetscCall(DMGetLocalVector(dmIn, &localU));
    8502:   PetscCall(DMGetLocalVector(dm, &localX));
    8503:   PetscCall(VecSet(localX, 0.));
    8504:   PetscCall(DMGlobalToLocalBegin(dmIn, U, mode, localU));
    8505:   PetscCall(DMGlobalToLocalEnd(dmIn, U, mode, localU));
    8506:   PetscCall(DMProjectFieldLabelLocal(dm, time, label, numIds, ids, Nc, comps, localU, funcs, mode, localX));
    8507:   PetscCall(DMLocalToGlobalBegin(dm, localX, mode, X));
    8508:   PetscCall(DMLocalToGlobalEnd(dm, localX, mode, X));
    8509:   PetscCall(DMRestoreLocalVector(dm, &localX));
    8510:   PetscCall(DMRestoreLocalVector(dmIn, &localU));
    8511:   PetscFunctionReturn(PETSC_SUCCESS);
    8512: }

    8514: /*@C
    8515:   DMProjectBdFieldLabelLocal - This projects the given function of the input fields into the function space provided, putting the coefficients in a local vector, calculating only over the portion of the domain boundary specified by the label.

    8517:   Not Collective

    8519:   Input Parameters:
    8520: + dm     - The `DM`
    8521: . time   - The time
    8522: . label  - The `DMLabel` marking the portion of the domain boundary to output
    8523: . numIds - The number of label ids to use
    8524: . ids    - The label ids to use for marking
    8525: . Nc     - The number of components to set in the output, or `PETSC_DETERMINE` for all components
    8526: . comps  - The components to set in the output, or `NULL` for all components
    8527: . localU - The input field vector
    8528: . funcs  - The functions to evaluate, one per field
    8529: - mode   - The insertion mode for values

    8531:   Output Parameter:
    8532: . localX - The output vector

    8534:   Calling sequence of `funcs`:
    8535: + dim          - The spatial dimension
    8536: . Nf           - The number of input fields
    8537: . NfAux        - The number of input auxiliary fields
    8538: . uOff         - The offset of each field in u[]
    8539: . uOff_x       - The offset of each field in u_x[]
    8540: . u            - The field values at this point in space
    8541: . u_t          - The field time derivative at this point in space (or NULL)
    8542: . u_x          - The field derivatives at this point in space
    8543: . aOff         - The offset of each auxiliary field in u[]
    8544: . aOff_x       - The offset of each auxiliary field in u_x[]
    8545: . a            - The auxiliary field values at this point in space
    8546: . a_t          - The auxiliary field time derivative at this point in space (or NULL)
    8547: . a_x          - The auxiliary field derivatives at this point in space
    8548: . t            - The current time
    8549: . x            - The coordinates of this point
    8550: . n            - The face normal
    8551: . numConstants - The number of constants
    8552: . constants    - The value of each constant
    8553: - f            - The value of the function at this point in space

    8555:   Level: intermediate

    8557:   Note:
    8558:   There are three different `DM`s that potentially interact in this function. The output `DM`, dm, specifies the layout of the values calculates by funcs.
    8559:   The input `DM`, attached to U, may be different. For example, you can input the solution over the full domain, but output over a piece of the boundary, or
    8560:   a subdomain. You can also output a different number of fields than the input, with different discretizations. Last the auxiliary `DM`, attached to the
    8561:   auxiliary field vector, which is attached to dm, can also be different. It can have a different topology, number of fields, and discretizations.

    8563:   Developer Notes:
    8564:   This API is specific to only particular usage of `DM`

    8566:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8568: .seealso: [](ch_dmbase), `DM`, `DMProjectField()`, `DMProjectFieldLabelLocal()`, `DMProjectFunction()`, `DMComputeL2Diff()`
    8569: @*/
    8570: PetscErrorCode DMProjectBdFieldLabelLocal(DM dm, PetscReal time, DMLabel label, PetscInt numIds, const PetscInt ids[], PetscInt Nc, const PetscInt comps[], Vec localU, void (**funcs)(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], const PetscReal n[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f[]), InsertMode mode, Vec localX)
    8571: {
    8572:   PetscFunctionBegin;
    8576:   PetscUseTypeMethod(dm, projectbdfieldlabellocal, time, label, numIds, ids, Nc, comps, localU, funcs, mode, localX);
    8577:   PetscFunctionReturn(PETSC_SUCCESS);
    8578: }

    8580: /*@C
    8581:   DMComputeL2Diff - This function computes the L_2 difference between a function u and an FEM interpolant solution u_h.

    8583:   Collective

    8585:   Input Parameters:
    8586: + dm    - The `DM`
    8587: . time  - The time
    8588: . funcs - The functions to evaluate for each field component
    8589: . ctxs  - Optional array of contexts to pass to each function, or NULL.
    8590: - X     - The coefficient vector u_h, a global vector

    8592:   Output Parameter:
    8593: . diff - The diff ||u - u_h||_2

    8595:   Level: developer

    8597:   Developer Notes:
    8598:   This API is specific to only particular usage of `DM`

    8600:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8602: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMComputeL2FieldDiff()`, `DMComputeL2GradientDiff()`
    8603: @*/
    8604: PetscErrorCode DMComputeL2Diff(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar *, void *), void **ctxs, Vec X, PetscReal *diff)
    8605: {
    8606:   PetscFunctionBegin;
    8609:   PetscUseTypeMethod(dm, computel2diff, time, funcs, ctxs, X, diff);
    8610:   PetscFunctionReturn(PETSC_SUCCESS);
    8611: }

    8613: /*@C
    8614:   DMComputeL2GradientDiff - This function computes the L_2 difference between the gradient of a function u and an FEM interpolant solution grad u_h.

    8616:   Collective

    8618:   Input Parameters:
    8619: + dm    - The `DM`
    8620: . time  - The time
    8621: . funcs - The gradient functions to evaluate for each field component
    8622: . ctxs  - Optional array of contexts to pass to each function, or NULL.
    8623: . X     - The coefficient vector u_h, a global vector
    8624: - n     - The vector to project along

    8626:   Output Parameter:
    8627: . diff - The diff ||(grad u - grad u_h) . n||_2

    8629:   Level: developer

    8631:   Developer Notes:
    8632:   This API is specific to only particular usage of `DM`

    8634:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8636: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMComputeL2Diff()`, `DMComputeL2FieldDiff()`
    8637: @*/
    8638: PetscErrorCode DMComputeL2GradientDiff(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt, PetscReal, const PetscReal[], const PetscReal[], PetscInt, PetscScalar *, void *), void **ctxs, Vec X, const PetscReal n[], PetscReal *diff)
    8639: {
    8640:   PetscFunctionBegin;
    8643:   PetscUseTypeMethod(dm, computel2gradientdiff, time, funcs, ctxs, X, n, diff);
    8644:   PetscFunctionReturn(PETSC_SUCCESS);
    8645: }

    8647: /*@C
    8648:   DMComputeL2FieldDiff - This function computes the L_2 difference between a function u and an FEM interpolant solution u_h, separated into field components.

    8650:   Collective

    8652:   Input Parameters:
    8653: + dm    - The `DM`
    8654: . time  - The time
    8655: . funcs - The functions to evaluate for each field component
    8656: . ctxs  - Optional array of contexts to pass to each function, or NULL.
    8657: - X     - The coefficient vector u_h, a global vector

    8659:   Output Parameter:
    8660: . diff - The array of differences, ||u^f - u^f_h||_2

    8662:   Level: developer

    8664:   Developer Notes:
    8665:   This API is specific to only particular usage of `DM`

    8667:   The notes need to provide some information about what has to be provided to the `DM` to be able to perform the computation.

    8669: .seealso: [](ch_dmbase), `DM`, `DMProjectFunction()`, `DMComputeL2GradientDiff()`
    8670: @*/
    8671: PetscErrorCode DMComputeL2FieldDiff(DM dm, PetscReal time, PetscErrorCode (**funcs)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar *, void *), void **ctxs, Vec X, PetscReal diff[])
    8672: {
    8673:   PetscFunctionBegin;
    8676:   PetscUseTypeMethod(dm, computel2fielddiff, time, funcs, ctxs, X, diff);
    8677:   PetscFunctionReturn(PETSC_SUCCESS);
    8678: }

    8680: /*@C
    8681:   DMGetNeighbors - Gets an array containing the MPI ranks of all the processes neighbors

    8683:   Not Collective

    8685:   Input Parameter:
    8686: . dm - The `DM`

    8688:   Output Parameters:
    8689: + nranks - the number of neighbours
    8690: - ranks  - the neighbors ranks

    8692:   Level: beginner

    8694:   Note:
    8695:   Do not free the array, it is freed when the `DM` is destroyed.

    8697: .seealso: [](ch_dmbase), `DM`, `DMDAGetNeighbors()`, `PetscSFGetRootRanks()`
    8698: @*/
    8699: PetscErrorCode DMGetNeighbors(DM dm, PetscInt *nranks, const PetscMPIInt *ranks[])
    8700: {
    8701:   PetscFunctionBegin;
    8703:   PetscUseTypeMethod(dm, getneighbors, nranks, ranks);
    8704:   PetscFunctionReturn(PETSC_SUCCESS);
    8705: }

    8707: #include <petsc/private/matimpl.h>

    8709: /*
    8710:     Converts the input vector to a ghosted vector and then calls the standard coloring code.
    8711:     This must be a different function because it requires DM which is not defined in the Mat library
    8712: */
    8713: static PetscErrorCode MatFDColoringApply_AIJDM(Mat J, MatFDColoring coloring, Vec x1, void *sctx)
    8714: {
    8715:   PetscFunctionBegin;
    8716:   if (coloring->ctype == IS_COLORING_LOCAL) {
    8717:     Vec x1local;
    8718:     DM  dm;
    8719:     PetscCall(MatGetDM(J, &dm));
    8720:     PetscCheck(dm, PetscObjectComm((PetscObject)J), PETSC_ERR_ARG_INCOMP, "IS_COLORING_LOCAL requires a DM");
    8721:     PetscCall(DMGetLocalVector(dm, &x1local));
    8722:     PetscCall(DMGlobalToLocalBegin(dm, x1, INSERT_VALUES, x1local));
    8723:     PetscCall(DMGlobalToLocalEnd(dm, x1, INSERT_VALUES, x1local));
    8724:     x1 = x1local;
    8725:   }
    8726:   PetscCall(MatFDColoringApply_AIJ(J, coloring, x1, sctx));
    8727:   if (coloring->ctype == IS_COLORING_LOCAL) {
    8728:     DM dm;
    8729:     PetscCall(MatGetDM(J, &dm));
    8730:     PetscCall(DMRestoreLocalVector(dm, &x1));
    8731:   }
    8732:   PetscFunctionReturn(PETSC_SUCCESS);
    8733: }

    8735: /*@
    8736:   MatFDColoringUseDM - allows a `MatFDColoring` object to use the `DM` associated with the matrix to compute a `IS_COLORING_LOCAL` coloring

    8738:   Input Parameters:
    8739: + coloring   - The matrix to get the `DM` from
    8740: - fdcoloring - the `MatFDColoring` object

    8742:   Level: advanced

    8744:   Developer Note:
    8745:   This routine exists because the PETSc `Mat` library does not know about the `DM` objects

    8747: .seealso: [](ch_dmbase), `DM`, `MatFDColoring`, `MatFDColoringCreate()`, `ISColoringType`
    8748: @*/
    8749: PetscErrorCode MatFDColoringUseDM(Mat coloring, MatFDColoring fdcoloring)
    8750: {
    8751:   PetscFunctionBegin;
    8752:   coloring->ops->fdcoloringapply = MatFDColoringApply_AIJDM;
    8753:   PetscFunctionReturn(PETSC_SUCCESS);
    8754: }

    8756: /*@
    8757:   DMGetCompatibility - determine if two `DM`s are compatible

    8759:   Collective

    8761:   Input Parameters:
    8762: + dm1 - the first `DM`
    8763: - dm2 - the second `DM`

    8765:   Output Parameters:
    8766: + compatible - whether or not the two `DM`s are compatible
    8767: - set        - whether or not the compatible value was actually determined and set

    8769:   Level: advanced

    8771:   Notes:
    8772:   Two `DM`s are deemed compatible if they represent the same parallel decomposition
    8773:   of the same topology. This implies that the section (field data) on one
    8774:   "makes sense" with respect to the topology and parallel decomposition of the other.
    8775:   Loosely speaking, compatible `DM`s represent the same domain and parallel
    8776:   decomposition, but hold different data.

    8778:   Typically, one would confirm compatibility if intending to simultaneously iterate
    8779:   over a pair of vectors obtained from different `DM`s.

    8781:   For example, two `DMDA` objects are compatible if they have the same local
    8782:   and global sizes and the same stencil width. They can have different numbers
    8783:   of degrees of freedom per node. Thus, one could use the node numbering from
    8784:   either `DM` in bounds for a loop over vectors derived from either `DM`.

    8786:   Consider the operation of summing data living on a 2-dof `DMDA` to data living
    8787:   on a 1-dof `DMDA`, which should be compatible, as in the following snippet.
    8788: .vb
    8789:   ...
    8790:   PetscCall(DMGetCompatibility(da1,da2,&compatible,&set));
    8791:   if (set && compatible)  {
    8792:     PetscCall(DMDAVecGetArrayDOF(da1,vec1,&arr1));
    8793:     PetscCall(DMDAVecGetArrayDOF(da2,vec2,&arr2));
    8794:     PetscCall(DMDAGetCorners(da1,&x,&y,NULL,&m,&n,NULL));
    8795:     for (j=y; j<y+n; ++j) {
    8796:       for (i=x; i<x+m, ++i) {
    8797:         arr1[j][i][0] = arr2[j][i][0] + arr2[j][i][1];
    8798:       }
    8799:     }
    8800:     PetscCall(DMDAVecRestoreArrayDOF(da1,vec1,&arr1));
    8801:     PetscCall(DMDAVecRestoreArrayDOF(da2,vec2,&arr2));
    8802:   } else {
    8803:     SETERRQ(PetscObjectComm((PetscObject)da1,PETSC_ERR_ARG_INCOMP,"DMDA objects incompatible");
    8804:   }
    8805:   ...
    8806: .ve

    8808:   Checking compatibility might be expensive for a given implementation of `DM`,
    8809:   or might be impossible to unambiguously confirm or deny. For this reason,
    8810:   this function may decline to determine compatibility, and hence users should
    8811:   always check the "set" output parameter.

    8813:   A `DM` is always compatible with itself.

    8815:   In the current implementation, `DM`s which live on "unequal" communicators
    8816:   (MPI_UNEQUAL in the terminology of MPI_Comm_compare()) are always deemed
    8817:   incompatible.

    8819:   This function is labeled "Collective," as information about all subdomains
    8820:   is required on each rank. However, in `DM` implementations which store all this
    8821:   information locally, this function may be merely "Logically Collective".

    8823:   Developer Note:
    8824:   Compatibility is assumed to be a symmetric concept; `DM` A is compatible with `DM` B
    8825:   iff B is compatible with A. Thus, this function checks the implementations
    8826:   of both dm and dmc (if they are of different types), attempting to determine
    8827:   compatibility. It is left to `DM` implementers to ensure that symmetry is
    8828:   preserved. The simplest way to do this is, when implementing type-specific
    8829:   logic for this function, is to check for existing logic in the implementation
    8830:   of other `DM` types and let *set = PETSC_FALSE if found.

    8832: .seealso: [](ch_dmbase), `DM`, `DMDACreateCompatibleDMDA()`, `DMStagCreateCompatibleDMStag()`
    8833: @*/
    8834: PetscErrorCode DMGetCompatibility(DM dm1, DM dm2, PetscBool *compatible, PetscBool *set)
    8835: {
    8836:   PetscMPIInt compareResult;
    8837:   DMType      type, type2;
    8838:   PetscBool   sameType;

    8840:   PetscFunctionBegin;

    8844:   /* Declare a DM compatible with itself */
    8845:   if (dm1 == dm2) {
    8846:     *set        = PETSC_TRUE;
    8847:     *compatible = PETSC_TRUE;
    8848:     PetscFunctionReturn(PETSC_SUCCESS);
    8849:   }

    8851:   /* Declare a DM incompatible with a DM that lives on an "unequal"
    8852:      communicator. Note that this does not preclude compatibility with
    8853:      DMs living on "congruent" or "similar" communicators, but this must be
    8854:      determined by the implementation-specific logic */
    8855:   PetscCallMPI(MPI_Comm_compare(PetscObjectComm((PetscObject)dm1), PetscObjectComm((PetscObject)dm2), &compareResult));
    8856:   if (compareResult == MPI_UNEQUAL) {
    8857:     *set        = PETSC_TRUE;
    8858:     *compatible = PETSC_FALSE;
    8859:     PetscFunctionReturn(PETSC_SUCCESS);
    8860:   }

    8862:   /* Pass to the implementation-specific routine, if one exists. */
    8863:   if (dm1->ops->getcompatibility) {
    8864:     PetscUseTypeMethod(dm1, getcompatibility, dm2, compatible, set);
    8865:     if (*set) PetscFunctionReturn(PETSC_SUCCESS);
    8866:   }

    8868:   /* If dm1 and dm2 are of different types, then attempt to check compatibility
    8869:      with an implementation of this function from dm2 */
    8870:   PetscCall(DMGetType(dm1, &type));
    8871:   PetscCall(DMGetType(dm2, &type2));
    8872:   PetscCall(PetscStrcmp(type, type2, &sameType));
    8873:   if (!sameType && dm2->ops->getcompatibility) {
    8874:     PetscUseTypeMethod(dm2, getcompatibility, dm1, compatible, set); /* Note argument order */
    8875:   } else {
    8876:     *set = PETSC_FALSE;
    8877:   }
    8878:   PetscFunctionReturn(PETSC_SUCCESS);
    8879: }

    8881: /*@C
    8882:   DMMonitorSet - Sets an additional monitor function that is to be used after a solve to monitor discretization performance.

    8884:   Logically Collective

    8886:   Input Parameters:
    8887: + dm             - the `DM`
    8888: . f              - the monitor function
    8889: . mctx           - [optional] user-defined context for private data for the monitor routine (use `NULL` if no context is desired)
    8890: - monitordestroy - [optional] routine that frees monitor context (may be `NULL`), see `PetscCtxDestroyFn` for the calling sequence

    8892:   Options Database Key:
    8893: . -dm_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to `DMMonitorSet()`, but
    8894:                        does not cancel those set via the options database.

    8896:   Level: intermediate

    8898:   Note:
    8899:   Several different monitoring routines may be set by calling
    8900:   `DMMonitorSet()` multiple times or with `DMMonitorSetFromOptions()`; all will be called in the
    8901:   order in which they were set.

    8903:   Fortran Note:
    8904:   Only a single monitor function can be set for each `DM` object

    8906:   Developer Note:
    8907:   This API has a generic name but seems specific to a very particular aspect of the use of `DM`

    8909: .seealso: [](ch_dmbase), `DM`, `DMMonitorCancel()`, `DMMonitorSetFromOptions()`, `DMMonitor()`, `PetscCtxDestroyFn`
    8910: @*/
    8911: PetscErrorCode DMMonitorSet(DM dm, PetscErrorCode (*f)(DM, void *), void *mctx, PetscCtxDestroyFn *monitordestroy)
    8912: {
    8913:   PetscInt m;

    8915:   PetscFunctionBegin;
    8917:   for (m = 0; m < dm->numbermonitors; ++m) {
    8918:     PetscBool identical;

    8920:     PetscCall(PetscMonitorCompare((PetscErrorCode (*)(void))f, mctx, monitordestroy, (PetscErrorCode (*)(void))dm->monitor[m], dm->monitorcontext[m], dm->monitordestroy[m], &identical));
    8921:     if (identical) PetscFunctionReturn(PETSC_SUCCESS);
    8922:   }
    8923:   PetscCheck(dm->numbermonitors < MAXDMMONITORS, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Too many monitors set");
    8924:   dm->monitor[dm->numbermonitors]          = f;
    8925:   dm->monitordestroy[dm->numbermonitors]   = monitordestroy;
    8926:   dm->monitorcontext[dm->numbermonitors++] = mctx;
    8927:   PetscFunctionReturn(PETSC_SUCCESS);
    8928: }

    8930: /*@
    8931:   DMMonitorCancel - Clears all the monitor functions for a `DM` object.

    8933:   Logically Collective

    8935:   Input Parameter:
    8936: . dm - the DM

    8938:   Options Database Key:
    8939: . -dm_monitor_cancel - cancels all monitors that have been hardwired
    8940:   into a code by calls to `DMonitorSet()`, but does not cancel those
    8941:   set via the options database

    8943:   Level: intermediate

    8945:   Note:
    8946:   There is no way to clear one specific monitor from a `DM` object.

    8948: .seealso: [](ch_dmbase), `DM`, `DMMonitorSet()`, `DMMonitorSetFromOptions()`, `DMMonitor()`
    8949: @*/
    8950: PetscErrorCode DMMonitorCancel(DM dm)
    8951: {
    8952:   PetscInt m;

    8954:   PetscFunctionBegin;
    8956:   for (m = 0; m < dm->numbermonitors; ++m) {
    8957:     if (dm->monitordestroy[m]) PetscCall((*dm->monitordestroy[m])(&dm->monitorcontext[m]));
    8958:   }
    8959:   dm->numbermonitors = 0;
    8960:   PetscFunctionReturn(PETSC_SUCCESS);
    8961: }

    8963: /*@C
    8964:   DMMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type indicated by the user

    8966:   Collective

    8968:   Input Parameters:
    8969: + dm           - `DM` object you wish to monitor
    8970: . name         - the monitor type one is seeking
    8971: . help         - message indicating what monitoring is done
    8972: . manual       - manual page for the monitor
    8973: . monitor      - the monitor function, this must use a `PetscViewerFormat` as its context
    8974: - monitorsetup - a function that is called once ONLY if the user selected this monitor that may set additional features of the `DM` or `PetscViewer` objects

    8976:   Output Parameter:
    8977: . flg - Flag set if the monitor was created

    8979:   Level: developer

    8981: .seealso: [](ch_dmbase), `DM`, `PetscOptionsCreateViewer()`, `PetscOptionsGetReal()`, `PetscOptionsHasName()`, `PetscOptionsGetString()`,
    8982:           `PetscOptionsGetIntArray()`, `PetscOptionsGetRealArray()`, `PetscOptionsBool()`
    8983:           `PetscOptionsInt()`, `PetscOptionsString()`, `PetscOptionsReal()`,
    8984:           `PetscOptionsName()`, `PetscOptionsBegin()`, `PetscOptionsEnd()`, `PetscOptionsHeadBegin()`,
    8985:           `PetscOptionsStringArray()`, `PetscOptionsRealArray()`, `PetscOptionsScalar()`,
    8986:           `PetscOptionsBoolGroupBegin()`, `PetscOptionsBoolGroup()`, `PetscOptionsBoolGroupEnd()`,
    8987:           `PetscOptionsFList()`, `PetscOptionsEList()`, `DMMonitor()`, `DMMonitorSet()`
    8988: @*/
    8989: PetscErrorCode DMMonitorSetFromOptions(DM dm, const char name[], const char help[], const char manual[], PetscErrorCode (*monitor)(DM, void *), PetscErrorCode (*monitorsetup)(DM, PetscViewerAndFormat *), PetscBool *flg)
    8990: {
    8991:   PetscViewer       viewer;
    8992:   PetscViewerFormat format;

    8994:   PetscFunctionBegin;
    8996:   PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)dm), ((PetscObject)dm)->options, ((PetscObject)dm)->prefix, name, &viewer, &format, flg));
    8997:   if (*flg) {
    8998:     PetscViewerAndFormat *vf;

    9000:     PetscCall(PetscViewerAndFormatCreate(viewer, format, &vf));
    9001:     PetscCall(PetscViewerDestroy(&viewer));
    9002:     if (monitorsetup) PetscCall((*monitorsetup)(dm, vf));
    9003:     PetscCall(DMMonitorSet(dm, monitor, vf, (PetscCtxDestroyFn *)PetscViewerAndFormatDestroy));
    9004:   }
    9005:   PetscFunctionReturn(PETSC_SUCCESS);
    9006: }

    9008: /*@
    9009:   DMMonitor - runs the user provided monitor routines, if they exist

    9011:   Collective

    9013:   Input Parameter:
    9014: . dm - The `DM`

    9016:   Level: developer

    9018:   Developer Note:
    9019:   Note should indicate when during the life of the `DM` the monitor is run. It appears to be
    9020:   related to the discretization process seems rather specialized since some `DM` have no
    9021:   concept of discretization.

    9023: .seealso: [](ch_dmbase), `DM`, `DMMonitorSet()`, `DMMonitorSetFromOptions()`
    9024: @*/
    9025: PetscErrorCode DMMonitor(DM dm)
    9026: {
    9027:   PetscInt m;

    9029:   PetscFunctionBegin;
    9030:   if (!dm) PetscFunctionReturn(PETSC_SUCCESS);
    9032:   for (m = 0; m < dm->numbermonitors; ++m) PetscCall((*dm->monitor[m])(dm, dm->monitorcontext[m]));
    9033:   PetscFunctionReturn(PETSC_SUCCESS);
    9034: }

    9036: /*@
    9037:   DMComputeError - Computes the error assuming the user has provided the exact solution functions

    9039:   Collective

    9041:   Input Parameters:
    9042: + dm  - The `DM`
    9043: - sol - The solution vector

    9045:   Input/Output Parameter:
    9046: . errors - An array of length Nf, the number of fields, or `NULL` for no output; on output
    9047:            contains the error in each field

    9049:   Output Parameter:
    9050: . errorVec - A vector to hold the cellwise error (may be `NULL`)

    9052:   Level: developer

    9054:   Note:
    9055:   The exact solutions come from the `PetscDS` object, and the time comes from `DMGetOutputSequenceNumber()`.

    9057: .seealso: [](ch_dmbase), `DM`, `DMMonitorSet()`, `DMGetRegionNumDS()`, `PetscDSGetExactSolution()`, `DMGetOutputSequenceNumber()`
    9058: @*/
    9059: PetscErrorCode DMComputeError(DM dm, Vec sol, PetscReal errors[], Vec *errorVec)
    9060: {
    9061:   PetscErrorCode (**exactSol)(PetscInt, PetscReal, const PetscReal[], PetscInt, PetscScalar[], void *);
    9062:   void    **ctxs;
    9063:   PetscReal time;
    9064:   PetscInt  Nf, f, Nds, s;

    9066:   PetscFunctionBegin;
    9067:   PetscCall(DMGetNumFields(dm, &Nf));
    9068:   PetscCall(PetscCalloc2(Nf, &exactSol, Nf, &ctxs));
    9069:   PetscCall(DMGetNumDS(dm, &Nds));
    9070:   for (s = 0; s < Nds; ++s) {
    9071:     PetscDS         ds;
    9072:     DMLabel         label;
    9073:     IS              fieldIS;
    9074:     const PetscInt *fields;
    9075:     PetscInt        dsNf;

    9077:     PetscCall(DMGetRegionNumDS(dm, s, &label, &fieldIS, &ds, NULL));
    9078:     PetscCall(PetscDSGetNumFields(ds, &dsNf));
    9079:     if (fieldIS) PetscCall(ISGetIndices(fieldIS, &fields));
    9080:     for (f = 0; f < dsNf; ++f) {
    9081:       const PetscInt field = fields[f];
    9082:       PetscCall(PetscDSGetExactSolution(ds, field, &exactSol[field], &ctxs[field]));
    9083:     }
    9084:     if (fieldIS) PetscCall(ISRestoreIndices(fieldIS, &fields));
    9085:   }
    9086:   for (f = 0; f < Nf; ++f) PetscCheck(exactSol[f], PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "DS must contain exact solution functions in order to calculate error, missing for field %" PetscInt_FMT, f);
    9087:   PetscCall(DMGetOutputSequenceNumber(dm, NULL, &time));
    9088:   if (errors) PetscCall(DMComputeL2FieldDiff(dm, time, exactSol, ctxs, sol, errors));
    9089:   if (errorVec) {
    9090:     DM             edm;
    9091:     DMPolytopeType ct;
    9092:     PetscBool      simplex;
    9093:     PetscInt       dim, cStart, Nf;

    9095:     PetscCall(DMClone(dm, &edm));
    9096:     PetscCall(DMGetDimension(edm, &dim));
    9097:     PetscCall(DMPlexGetHeightStratum(dm, 0, &cStart, NULL));
    9098:     PetscCall(DMPlexGetCellType(dm, cStart, &ct));
    9099:     simplex = DMPolytopeTypeGetNumVertices(ct) == DMPolytopeTypeGetDim(ct) + 1 ? PETSC_TRUE : PETSC_FALSE;
    9100:     PetscCall(DMGetNumFields(dm, &Nf));
    9101:     for (f = 0; f < Nf; ++f) {
    9102:       PetscFE         fe, efe;
    9103:       PetscQuadrature q;
    9104:       const char     *name;

    9106:       PetscCall(DMGetField(dm, f, NULL, (PetscObject *)&fe));
    9107:       PetscCall(PetscFECreateLagrange(PETSC_COMM_SELF, dim, Nf, simplex, 0, PETSC_DETERMINE, &efe));
    9108:       PetscCall(PetscObjectGetName((PetscObject)fe, &name));
    9109:       PetscCall(PetscObjectSetName((PetscObject)efe, name));
    9110:       PetscCall(PetscFEGetQuadrature(fe, &q));
    9111:       PetscCall(PetscFESetQuadrature(efe, q));
    9112:       PetscCall(DMSetField(edm, f, NULL, (PetscObject)efe));
    9113:       PetscCall(PetscFEDestroy(&efe));
    9114:     }
    9115:     PetscCall(DMCreateDS(edm));

    9117:     PetscCall(DMCreateGlobalVector(edm, errorVec));
    9118:     PetscCall(PetscObjectSetName((PetscObject)*errorVec, "Error"));
    9119:     PetscCall(DMPlexComputeL2DiffVec(dm, time, exactSol, ctxs, sol, *errorVec));
    9120:     PetscCall(DMDestroy(&edm));
    9121:   }
    9122:   PetscCall(PetscFree2(exactSol, ctxs));
    9123:   PetscFunctionReturn(PETSC_SUCCESS);
    9124: }

    9126: /*@
    9127:   DMGetNumAuxiliaryVec - Get the number of auxiliary vectors associated with this `DM`

    9129:   Not Collective

    9131:   Input Parameter:
    9132: . dm - The `DM`

    9134:   Output Parameter:
    9135: . numAux - The number of auxiliary data vectors

    9137:   Level: advanced

    9139: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMSetAuxiliaryVec()`, `DMGetAuxiliaryLabels()`, `DMGetAuxiliaryVec()`
    9140: @*/
    9141: PetscErrorCode DMGetNumAuxiliaryVec(DM dm, PetscInt *numAux)
    9142: {
    9143:   PetscFunctionBegin;
    9145:   PetscCall(PetscHMapAuxGetSize(dm->auxData, numAux));
    9146:   PetscFunctionReturn(PETSC_SUCCESS);
    9147: }

    9149: /*@
    9150:   DMGetAuxiliaryVec - Get the auxiliary vector for region specified by the given label and value, and equation part

    9152:   Not Collective

    9154:   Input Parameters:
    9155: + dm    - The `DM`
    9156: . label - The `DMLabel`
    9157: . value - The label value indicating the region
    9158: - part  - The equation part, or 0 if unused

    9160:   Output Parameter:
    9161: . aux - The `Vec` holding auxiliary field data

    9163:   Level: advanced

    9165:   Note:
    9166:   If no auxiliary vector is found for this (label, value), (NULL, 0, 0) is checked as well.

    9168: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMSetAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryLabels()`
    9169: @*/
    9170: PetscErrorCode DMGetAuxiliaryVec(DM dm, DMLabel label, PetscInt value, PetscInt part, Vec *aux)
    9171: {
    9172:   PetscHashAuxKey key, wild = {NULL, 0, 0};
    9173:   PetscBool       has;

    9175:   PetscFunctionBegin;
    9178:   key.label = label;
    9179:   key.value = value;
    9180:   key.part  = part;
    9181:   PetscCall(PetscHMapAuxHas(dm->auxData, key, &has));
    9182:   if (has) PetscCall(PetscHMapAuxGet(dm->auxData, key, aux));
    9183:   else PetscCall(PetscHMapAuxGet(dm->auxData, wild, aux));
    9184:   PetscFunctionReturn(PETSC_SUCCESS);
    9185: }

    9187: /*@
    9188:   DMSetAuxiliaryVec - Set an auxiliary vector for region specified by the given label and value, and equation part

    9190:   Not Collective because auxiliary vectors are not parallel

    9192:   Input Parameters:
    9193: + dm    - The `DM`
    9194: . label - The `DMLabel`
    9195: . value - The label value indicating the region
    9196: . part  - The equation part, or 0 if unused
    9197: - aux   - The `Vec` holding auxiliary field data

    9199:   Level: advanced

    9201: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMGetAuxiliaryLabels()`, `DMCopyAuxiliaryVec()`
    9202: @*/
    9203: PetscErrorCode DMSetAuxiliaryVec(DM dm, DMLabel label, PetscInt value, PetscInt part, Vec aux)
    9204: {
    9205:   Vec             old;
    9206:   PetscHashAuxKey key;

    9208:   PetscFunctionBegin;
    9211:   key.label = label;
    9212:   key.value = value;
    9213:   key.part  = part;
    9214:   PetscCall(PetscHMapAuxGet(dm->auxData, key, &old));
    9215:   PetscCall(PetscObjectReference((PetscObject)aux));
    9216:   if (!aux) PetscCall(PetscHMapAuxDel(dm->auxData, key));
    9217:   else PetscCall(PetscHMapAuxSet(dm->auxData, key, aux));
    9218:   PetscCall(VecDestroy(&old));
    9219:   PetscFunctionReturn(PETSC_SUCCESS);
    9220: }

    9222: /*@
    9223:   DMGetAuxiliaryLabels - Get the labels, values, and parts for all auxiliary vectors in this `DM`

    9225:   Not Collective

    9227:   Input Parameter:
    9228: . dm - The `DM`

    9230:   Output Parameters:
    9231: + labels - The `DMLabel`s for each `Vec`
    9232: . values - The label values for each `Vec`
    9233: - parts  - The equation parts for each `Vec`

    9235:   Level: advanced

    9237:   Note:
    9238:   The arrays passed in must be at least as large as `DMGetNumAuxiliaryVec()`.

    9240: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMSetAuxiliaryVec()`, `DMCopyAuxiliaryVec()`
    9241: @*/
    9242: PetscErrorCode DMGetAuxiliaryLabels(DM dm, DMLabel labels[], PetscInt values[], PetscInt parts[])
    9243: {
    9244:   PetscHashAuxKey *keys;
    9245:   PetscInt         n, i, off = 0;

    9247:   PetscFunctionBegin;
    9249:   PetscAssertPointer(labels, 2);
    9250:   PetscAssertPointer(values, 3);
    9251:   PetscAssertPointer(parts, 4);
    9252:   PetscCall(DMGetNumAuxiliaryVec(dm, &n));
    9253:   PetscCall(PetscMalloc1(n, &keys));
    9254:   PetscCall(PetscHMapAuxGetKeys(dm->auxData, &off, keys));
    9255:   for (i = 0; i < n; ++i) {
    9256:     labels[i] = keys[i].label;
    9257:     values[i] = keys[i].value;
    9258:     parts[i]  = keys[i].part;
    9259:   }
    9260:   PetscCall(PetscFree(keys));
    9261:   PetscFunctionReturn(PETSC_SUCCESS);
    9262: }

    9264: /*@
    9265:   DMCopyAuxiliaryVec - Copy the auxiliary vector data on a `DM` to a new `DM`

    9267:   Not Collective

    9269:   Input Parameter:
    9270: . dm - The `DM`

    9272:   Output Parameter:
    9273: . dmNew - The new `DM`, now with the same auxiliary data

    9275:   Level: advanced

    9277:   Note:
    9278:   This is a shallow copy of the auxiliary vectors

    9280: .seealso: [](ch_dmbase), `DM`, `DMClearAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMSetAuxiliaryVec()`
    9281: @*/
    9282: PetscErrorCode DMCopyAuxiliaryVec(DM dm, DM dmNew)
    9283: {
    9284:   PetscFunctionBegin;
    9287:   if (dm == dmNew) PetscFunctionReturn(PETSC_SUCCESS);
    9288:   PetscCall(DMClearAuxiliaryVec(dmNew));

    9290:   PetscCall(PetscHMapAuxDestroy(&dmNew->auxData));
    9291:   PetscCall(PetscHMapAuxDuplicate(dm->auxData, &dmNew->auxData));
    9292:   {
    9293:     Vec     *auxData;
    9294:     PetscInt n, i, off = 0;

    9296:     PetscCall(PetscHMapAuxGetSize(dmNew->auxData, &n));
    9297:     PetscCall(PetscMalloc1(n, &auxData));
    9298:     PetscCall(PetscHMapAuxGetVals(dmNew->auxData, &off, auxData));
    9299:     for (i = 0; i < n; ++i) PetscCall(PetscObjectReference((PetscObject)auxData[i]));
    9300:     PetscCall(PetscFree(auxData));
    9301:   }
    9302:   PetscFunctionReturn(PETSC_SUCCESS);
    9303: }

    9305: /*@
    9306:   DMClearAuxiliaryVec - Destroys the auxiliary vector information and creates a new empty one

    9308:   Not Collective

    9310:   Input Parameter:
    9311: . dm - The `DM`

    9313:   Level: advanced

    9315: .seealso: [](ch_dmbase), `DM`, `DMCopyAuxiliaryVec()`, `DMGetNumAuxiliaryVec()`, `DMGetAuxiliaryVec()`, `DMSetAuxiliaryVec()`
    9316: @*/
    9317: PetscErrorCode DMClearAuxiliaryVec(DM dm)
    9318: {
    9319:   Vec     *auxData;
    9320:   PetscInt n, i, off = 0;

    9322:   PetscFunctionBegin;
    9323:   PetscCall(PetscHMapAuxGetSize(dm->auxData, &n));
    9324:   PetscCall(PetscMalloc1(n, &auxData));
    9325:   PetscCall(PetscHMapAuxGetVals(dm->auxData, &off, auxData));
    9326:   for (i = 0; i < n; ++i) PetscCall(VecDestroy(&auxData[i]));
    9327:   PetscCall(PetscFree(auxData));
    9328:   PetscCall(PetscHMapAuxDestroy(&dm->auxData));
    9329:   PetscCall(PetscHMapAuxCreate(&dm->auxData));
    9330:   PetscFunctionReturn(PETSC_SUCCESS);
    9331: }

    9333: /*@
    9334:   DMPolytopeMatchOrientation - Determine an orientation (transformation) that takes the source face arrangement to the target face arrangement

    9336:   Not Collective

    9338:   Input Parameters:
    9339: + ct         - The `DMPolytopeType`
    9340: . sourceCone - The source arrangement of faces
    9341: - targetCone - The target arrangement of faces

    9343:   Output Parameters:
    9344: + ornt  - The orientation (transformation) which will take the source arrangement to the target arrangement
    9345: - found - Flag indicating that a suitable orientation was found

    9347:   Level: advanced

    9349:   Note:
    9350:   An arrangement is a face order combined with an orientation for each face

    9352:   Each orientation (transformation) is labeled with an integer from negative `DMPolytopeTypeGetNumArrangements(ct)`/2 to `DMPolytopeTypeGetNumArrangements(ct)`/2
    9353:   that labels each arrangement (face ordering plus orientation for each face).

    9355:   See `DMPolytopeMatchVertexOrientation()` to find a new vertex orientation that takes the source vertex arrangement to the target vertex arrangement

    9357: .seealso: [](ch_dmbase), `DM`, `DMPolytopeGetOrientation()`, `DMPolytopeMatchVertexOrientation()`, `DMPolytopeGetVertexOrientation()`
    9358: @*/
    9359: PetscErrorCode DMPolytopeMatchOrientation(DMPolytopeType ct, const PetscInt sourceCone[], const PetscInt targetCone[], PetscInt *ornt, PetscBool *found)
    9360: {
    9361:   const PetscInt cS = DMPolytopeTypeGetConeSize(ct);
    9362:   const PetscInt nO = DMPolytopeTypeGetNumArrangements(ct) / 2;
    9363:   PetscInt       o, c;

    9365:   PetscFunctionBegin;
    9366:   if (!nO) {
    9367:     *ornt  = 0;
    9368:     *found = PETSC_TRUE;
    9369:     PetscFunctionReturn(PETSC_SUCCESS);
    9370:   }
    9371:   for (o = -nO; o < nO; ++o) {
    9372:     const PetscInt *arr = DMPolytopeTypeGetArrangement(ct, o);

    9374:     for (c = 0; c < cS; ++c)
    9375:       if (sourceCone[arr[c * 2]] != targetCone[c]) break;
    9376:     if (c == cS) {
    9377:       *ornt = o;
    9378:       break;
    9379:     }
    9380:   }
    9381:   *found = o == nO ? PETSC_FALSE : PETSC_TRUE;
    9382:   PetscFunctionReturn(PETSC_SUCCESS);
    9383: }

    9385: /*@
    9386:   DMPolytopeGetOrientation - Determine an orientation (transformation) that takes the source face arrangement to the target face arrangement

    9388:   Not Collective

    9390:   Input Parameters:
    9391: + ct         - The `DMPolytopeType`
    9392: . sourceCone - The source arrangement of faces
    9393: - targetCone - The target arrangement of faces

    9395:   Output Parameter:
    9396: . ornt - The orientation (transformation) which will take the source arrangement to the target arrangement

    9398:   Level: advanced

    9400:   Note:
    9401:   This function is the same as `DMPolytopeMatchOrientation()` except it will generate an error if no suitable orientation can be found.

    9403:   Developer Note:
    9404:   It is unclear why this function needs to exist since one can simply call `DMPolytopeMatchOrientation()` and error if none is found

    9406: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMPolytopeMatchOrientation()`, `DMPolytopeGetVertexOrientation()`, `DMPolytopeMatchVertexOrientation()`
    9407: @*/
    9408: PetscErrorCode DMPolytopeGetOrientation(DMPolytopeType ct, const PetscInt sourceCone[], const PetscInt targetCone[], PetscInt *ornt)
    9409: {
    9410:   PetscBool found;

    9412:   PetscFunctionBegin;
    9413:   PetscCall(DMPolytopeMatchOrientation(ct, sourceCone, targetCone, ornt, &found));
    9414:   PetscCheck(found, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find orientation for %s", DMPolytopeTypes[ct]);
    9415:   PetscFunctionReturn(PETSC_SUCCESS);
    9416: }

    9418: /*@
    9419:   DMPolytopeMatchVertexOrientation - Determine an orientation (transformation) that takes the source vertex arrangement to the target vertex arrangement

    9421:   Not Collective

    9423:   Input Parameters:
    9424: + ct         - The `DMPolytopeType`
    9425: . sourceVert - The source arrangement of vertices
    9426: - targetVert - The target arrangement of vertices

    9428:   Output Parameters:
    9429: + ornt  - The orientation (transformation) which will take the source arrangement to the target arrangement
    9430: - found - Flag indicating that a suitable orientation was found

    9432:   Level: advanced

    9434:   Notes:
    9435:   An arrangement is a vertex order

    9437:   Each orientation (transformation) is labeled with an integer from negative `DMPolytopeTypeGetNumArrangements(ct)`/2 to `DMPolytopeTypeGetNumArrangements(ct)`/2
    9438:   that labels each arrangement (vertex ordering).

    9440:   See `DMPolytopeMatchOrientation()` to find a new face orientation that takes the source face arrangement to the target face arrangement

    9442: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMPolytopeGetOrientation()`, `DMPolytopeMatchOrientation()`, `DMPolytopeTypeGetNumVertices()`, `DMPolytopeTypeGetVertexArrangement()`
    9443: @*/
    9444: PetscErrorCode DMPolytopeMatchVertexOrientation(DMPolytopeType ct, const PetscInt sourceVert[], const PetscInt targetVert[], PetscInt *ornt, PetscBool *found)
    9445: {
    9446:   const PetscInt cS = DMPolytopeTypeGetNumVertices(ct);
    9447:   const PetscInt nO = DMPolytopeTypeGetNumArrangements(ct) / 2;
    9448:   PetscInt       o, c;

    9450:   PetscFunctionBegin;
    9451:   if (!nO) {
    9452:     *ornt  = 0;
    9453:     *found = PETSC_TRUE;
    9454:     PetscFunctionReturn(PETSC_SUCCESS);
    9455:   }
    9456:   for (o = -nO; o < nO; ++o) {
    9457:     const PetscInt *arr = DMPolytopeTypeGetVertexArrangement(ct, o);

    9459:     for (c = 0; c < cS; ++c)
    9460:       if (sourceVert[arr[c]] != targetVert[c]) break;
    9461:     if (c == cS) {
    9462:       *ornt = o;
    9463:       break;
    9464:     }
    9465:   }
    9466:   *found = o == nO ? PETSC_FALSE : PETSC_TRUE;
    9467:   PetscFunctionReturn(PETSC_SUCCESS);
    9468: }

    9470: /*@
    9471:   DMPolytopeGetVertexOrientation - Determine an orientation (transformation) that takes the source vertex arrangement to the target vertex arrangement

    9473:   Not Collective

    9475:   Input Parameters:
    9476: + ct         - The `DMPolytopeType`
    9477: . sourceCone - The source arrangement of vertices
    9478: - targetCone - The target arrangement of vertices

    9480:   Output Parameter:
    9481: . ornt - The orientation (transformation) which will take the source arrangement to the target arrangement

    9483:   Level: advanced

    9485:   Note:
    9486:   This function is the same as `DMPolytopeMatchVertexOrientation()` except it errors if not orientation is possible.

    9488:   Developer Note:
    9489:   It is unclear why this function needs to exist since one can simply call `DMPolytopeMatchVertexOrientation()` and error if none is found

    9491: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMPolytopeMatchVertexOrientation()`, `DMPolytopeGetOrientation()`
    9492: @*/
    9493: PetscErrorCode DMPolytopeGetVertexOrientation(DMPolytopeType ct, const PetscInt sourceCone[], const PetscInt targetCone[], PetscInt *ornt)
    9494: {
    9495:   PetscBool found;

    9497:   PetscFunctionBegin;
    9498:   PetscCall(DMPolytopeMatchVertexOrientation(ct, sourceCone, targetCone, ornt, &found));
    9499:   PetscCheck(found, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find orientation for %s", DMPolytopeTypes[ct]);
    9500:   PetscFunctionReturn(PETSC_SUCCESS);
    9501: }

    9503: /*@
    9504:   DMPolytopeInCellTest - Check whether a point lies inside the reference cell of given type

    9506:   Not Collective

    9508:   Input Parameters:
    9509: + ct    - The `DMPolytopeType`
    9510: - point - Coordinates of the point

    9512:   Output Parameter:
    9513: . inside - Flag indicating whether the point is inside the reference cell of given type

    9515:   Level: advanced

    9517: .seealso: [](ch_dmbase), `DM`, `DMPolytopeType`, `DMLocatePoints()`
    9518: @*/
    9519: PetscErrorCode DMPolytopeInCellTest(DMPolytopeType ct, const PetscReal point[], PetscBool *inside)
    9520: {
    9521:   PetscReal sum = 0.0;
    9522:   PetscInt  d;

    9524:   PetscFunctionBegin;
    9525:   *inside = PETSC_TRUE;
    9526:   switch (ct) {
    9527:   case DM_POLYTOPE_TRIANGLE:
    9528:   case DM_POLYTOPE_TETRAHEDRON:
    9529:     for (d = 0; d < DMPolytopeTypeGetDim(ct); ++d) {
    9530:       if (point[d] < -1.0) {
    9531:         *inside = PETSC_FALSE;
    9532:         break;
    9533:       }
    9534:       sum += point[d];
    9535:     }
    9536:     if (sum > PETSC_SMALL) {
    9537:       *inside = PETSC_FALSE;
    9538:       break;
    9539:     }
    9540:     break;
    9541:   case DM_POLYTOPE_QUADRILATERAL:
    9542:   case DM_POLYTOPE_HEXAHEDRON:
    9543:     for (d = 0; d < DMPolytopeTypeGetDim(ct); ++d)
    9544:       if (PetscAbsReal(point[d]) > 1. + PETSC_SMALL) {
    9545:         *inside = PETSC_FALSE;
    9546:         break;
    9547:       }
    9548:     break;
    9549:   default:
    9550:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unsupported polytope type %s", DMPolytopeTypes[ct]);
    9551:   }
    9552:   PetscFunctionReturn(PETSC_SUCCESS);
    9553: }

    9555: /*@
    9556:   DMReorderSectionSetDefault - Set flag indicating whether the local section should be reordered by default

    9558:   Logically collective

    9560:   Input Parameters:
    9561: + dm      - The DM
    9562: - reorder - Flag for reordering

    9564:   Level: intermediate

    9566: .seealso: `DMReorderSectionGetDefault()`
    9567: @*/
    9568: PetscErrorCode DMReorderSectionSetDefault(DM dm, DMReorderDefaultFlag reorder)
    9569: {
    9570:   PetscFunctionBegin;
    9572:   PetscTryMethod(dm, "DMReorderSectionSetDefault_C", (DM, DMReorderDefaultFlag), (dm, reorder));
    9573:   PetscFunctionReturn(PETSC_SUCCESS);
    9574: }

    9576: /*@
    9577:   DMReorderSectionGetDefault - Get flag indicating whether the local section should be reordered by default

    9579:   Not collective

    9581:   Input Parameter:
    9582: . dm - The DM

    9584:   Output Parameter:
    9585: . reorder - Flag for reordering

    9587:   Level: intermediate

    9589: .seealso: `DMReorderSetDefault()`
    9590: @*/
    9591: PetscErrorCode DMReorderSectionGetDefault(DM dm, DMReorderDefaultFlag *reorder)
    9592: {
    9593:   PetscFunctionBegin;
    9595:   PetscAssertPointer(reorder, 2);
    9596:   *reorder = DM_REORDER_DEFAULT_NOTSET;
    9597:   PetscTryMethod(dm, "DMReorderSectionGetDefault_C", (DM, DMReorderDefaultFlag *), (dm, reorder));
    9598:   PetscFunctionReturn(PETSC_SUCCESS);
    9599: }

    9601: /*@
    9602:   DMReorderSectionSetType - Set the type of local section reordering

    9604:   Logically collective

    9606:   Input Parameters:
    9607: + dm      - The DM
    9608: - reorder - The reordering method

    9610:   Level: intermediate

    9612: .seealso: `DMReorderSectionGetType()`, `DMReorderSectionSetDefault()`
    9613: @*/
    9614: PetscErrorCode DMReorderSectionSetType(DM dm, MatOrderingType reorder)
    9615: {
    9616:   PetscFunctionBegin;
    9618:   PetscTryMethod(dm, "DMReorderSectionSetType_C", (DM, MatOrderingType), (dm, reorder));
    9619:   PetscFunctionReturn(PETSC_SUCCESS);
    9620: }

    9622: /*@
    9623:   DMReorderSectionGetType - Get the reordering type for the local section

    9625:   Not collective

    9627:   Input Parameter:
    9628: . dm - The DM

    9630:   Output Parameter:
    9631: . reorder - The reordering method

    9633:   Level: intermediate

    9635: .seealso: `DMReorderSetDefault()`, `DMReorderSectionGetDefault()`
    9636: @*/
    9637: PetscErrorCode DMReorderSectionGetType(DM dm, MatOrderingType *reorder)
    9638: {
    9639:   PetscFunctionBegin;
    9641:   PetscAssertPointer(reorder, 2);
    9642:   *reorder = NULL;
    9643:   PetscTryMethod(dm, "DMReorderSectionGetType_C", (DM, MatOrderingType *), (dm, reorder));
    9644:   PetscFunctionReturn(PETSC_SUCCESS);
    9645: }