Date: 2025-03-29T05:58:34+00:00

Actual source code: cdiagonal.c

      1: #include <petsc/private/matimpl.h>

      3: typedef struct {
      4:   PetscScalar diag;
      5: } Mat_ConstantDiagonal;

      7: static PetscErrorCode MatAXPY_ConstantDiagonal(Mat Y, PetscScalar a, Mat X, MatStructure str)
      8: {
      9:   Mat_ConstantDiagonal *yctx = (Mat_ConstantDiagonal *)Y->data;
     10:   Mat_ConstantDiagonal *xctx = (Mat_ConstantDiagonal *)X->data;

     12:   PetscFunctionBegin;
     13:   yctx->diag += a * xctx->diag;
     14:   PetscFunctionReturn(PETSC_SUCCESS);
     15: }

     17: static PetscErrorCode MatEqual_ConstantDiagonal(Mat Y, Mat X, PetscBool *equal)
     18: {
     19:   Mat_ConstantDiagonal *yctx = (Mat_ConstantDiagonal *)Y->data;
     20:   Mat_ConstantDiagonal *xctx = (Mat_ConstantDiagonal *)X->data;

     22:   PetscFunctionBegin;
     23:   *equal = (yctx->diag == xctx->diag) ? PETSC_TRUE : PETSC_FALSE;
     24:   PetscFunctionReturn(PETSC_SUCCESS);
     25: }

     27: static PetscErrorCode MatGetRow_ConstantDiagonal(Mat A, PetscInt row, PetscInt *ncols, PetscInt *cols[], PetscScalar *vals[])
     28: {
     29:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)A->data;

     31:   PetscFunctionBegin;
     32:   if (ncols) *ncols = 1;
     33:   if (cols) {
     34:     PetscCall(PetscMalloc1(1, cols));
     35:     (*cols)[0] = row;
     36:   }
     37:   if (vals) {
     38:     PetscCall(PetscMalloc1(1, vals));
     39:     (*vals)[0] = ctx->diag;
     40:   }
     41:   PetscFunctionReturn(PETSC_SUCCESS);
     42: }

     44: static PetscErrorCode MatRestoreRow_ConstantDiagonal(Mat A, PetscInt row, PetscInt *ncols, PetscInt *cols[], PetscScalar *vals[])
     45: {
     46:   PetscFunctionBegin;
     47:   if (cols) PetscCall(PetscFree(*cols));
     48:   if (vals) PetscCall(PetscFree(*vals));
     49:   PetscFunctionReturn(PETSC_SUCCESS);
     50: }

     52: static PetscErrorCode MatMultAdd_ConstantDiagonal(Mat mat, Vec v1, Vec v2, Vec v3)
     53: {
     54:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)mat->data;

     56:   PetscFunctionBegin;
     57:   if (v2 == v3) {
     58:     PetscCall(VecAXPBY(v3, ctx->diag, 1.0, v1));
     59:   } else {
     60:     PetscCall(VecAXPBYPCZ(v3, ctx->diag, 1.0, 0.0, v1, v2));
     61:   }
     62:   PetscFunctionReturn(PETSC_SUCCESS);
     63: }

     65: static PetscErrorCode MatMultHermitianTransposeAdd_ConstantDiagonal(Mat mat, Vec v1, Vec v2, Vec v3)
     66: {
     67:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)mat->data;

     69:   PetscFunctionBegin;
     70:   if (v2 == v3) {
     71:     PetscCall(VecAXPBY(v3, PetscConj(ctx->diag), 1.0, v1));
     72:   } else {
     73:     PetscCall(VecAXPBYPCZ(v3, PetscConj(ctx->diag), 1.0, 0.0, v1, v2));
     74:   }
     75:   PetscFunctionReturn(PETSC_SUCCESS);
     76: }

     78: static PetscErrorCode MatNorm_ConstantDiagonal(Mat A, NormType type, PetscReal *nrm)
     79: {
     80:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)A->data;

     82:   PetscFunctionBegin;
     83:   if (type == NORM_FROBENIUS || type == NORM_2 || type == NORM_1 || type == NORM_INFINITY) *nrm = PetscAbsScalar(ctx->diag);
     84:   else SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_SUP, "Unsupported norm");
     85:   PetscFunctionReturn(PETSC_SUCCESS);
     86: }

     88: static PetscErrorCode MatCreateSubMatrices_ConstantDiagonal(Mat A, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *submat[])

     90: {
     91:   Mat B;

     93:   PetscFunctionBegin;
     94:   PetscCall(MatConvert(A, MATAIJ, MAT_INITIAL_MATRIX, &B));
     95:   PetscCall(MatCreateSubMatrices(B, n, irow, icol, scall, submat));
     96:   PetscCall(MatDestroy(&B));
     97:   PetscFunctionReturn(PETSC_SUCCESS);
     98: }

    100: static PetscErrorCode MatDuplicate_ConstantDiagonal(Mat A, MatDuplicateOption op, Mat *B)
    101: {
    102:   Mat_ConstantDiagonal *actx = (Mat_ConstantDiagonal *)A->data;

    104:   PetscFunctionBegin;
    105:   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), B));
    106:   PetscCall(MatSetSizes(*B, A->rmap->n, A->cmap->n, A->rmap->N, A->cmap->N));
    107:   PetscCall(MatSetBlockSizesFromMats(*B, A, A));
    108:   PetscCall(MatSetType(*B, MATCONSTANTDIAGONAL));
    109:   PetscCall(PetscLayoutReference(A->rmap, &(*B)->rmap));
    110:   PetscCall(PetscLayoutReference(A->cmap, &(*B)->cmap));
    111:   if (op == MAT_COPY_VALUES) {
    112:     Mat_ConstantDiagonal *bctx = (Mat_ConstantDiagonal *)(*B)->data;
    113:     bctx->diag                 = actx->diag;
    114:   }
    115:   PetscFunctionReturn(PETSC_SUCCESS);
    116: }

    118: static PetscErrorCode MatMissingDiagonal_ConstantDiagonal(Mat mat, PetscBool *missing, PetscInt *dd)
    119: {
    120:   PetscFunctionBegin;
    121:   *missing = PETSC_FALSE;
    122:   PetscFunctionReturn(PETSC_SUCCESS);
    123: }

    125: static PetscErrorCode MatDestroy_ConstantDiagonal(Mat mat)
    126: {
    127:   PetscFunctionBegin;
    128:   PetscCall(PetscFree(mat->data));
    129:   mat->structural_symmetry_eternal = PETSC_FALSE;
    130:   mat->symmetry_eternal            = PETSC_FALSE;
    131:   PetscFunctionReturn(PETSC_SUCCESS);
    132: }

    134: static PetscErrorCode MatView_ConstantDiagonal(Mat J, PetscViewer viewer)
    135: {
    136:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)J->data;
    137:   PetscBool             iascii;

    139:   PetscFunctionBegin;
    140:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
    141:   if (iascii) {
    142:     PetscViewerFormat format;

    144:     PetscCall(PetscViewerGetFormat(viewer, &format));
    145:     if (format == PETSC_VIEWER_ASCII_FACTOR_INFO || format == PETSC_VIEWER_ASCII_INFO) PetscFunctionReturn(PETSC_SUCCESS);
    146: #if defined(PETSC_USE_COMPLEX)
    147:     PetscCall(PetscViewerASCIIPrintf(viewer, "Diagonal value: %g + i %g\n", (double)PetscRealPart(ctx->diag), (double)PetscImaginaryPart(ctx->diag)));
    148: #else
    149:     PetscCall(PetscViewerASCIIPrintf(viewer, "Diagonal value: %g\n", (double)ctx->diag));
    150: #endif
    151:   }
    152:   PetscFunctionReturn(PETSC_SUCCESS);
    153: }

    155: static PetscErrorCode MatMult_ConstantDiagonal(Mat J, Vec x, Vec y)
    156: {
    157:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)J->data;

    159:   PetscFunctionBegin;
    160:   PetscCall(VecAXPBY(y, ctx->diag, 0.0, x));
    161:   PetscFunctionReturn(PETSC_SUCCESS);
    162: }

    164: static PetscErrorCode MatMultHermitianTranspose_ConstantDiagonal(Mat J, Vec x, Vec y)
    165: {
    166:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)J->data;

    168:   PetscFunctionBegin;
    169:   PetscCall(VecAXPBY(y, PetscConj(ctx->diag), 0.0, x));
    170:   PetscFunctionReturn(PETSC_SUCCESS);
    171: }

    173: static PetscErrorCode MatGetDiagonal_ConstantDiagonal(Mat J, Vec x)
    174: {
    175:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)J->data;

    177:   PetscFunctionBegin;
    178:   PetscCall(VecSet(x, ctx->diag));
    179:   PetscFunctionReturn(PETSC_SUCCESS);
    180: }

    182: static PetscErrorCode MatShift_ConstantDiagonal(Mat Y, PetscScalar a)
    183: {
    184:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)Y->data;

    186:   PetscFunctionBegin;
    187:   ctx->diag += a;
    188:   PetscFunctionReturn(PETSC_SUCCESS);
    189: }

    191: static PetscErrorCode MatScale_ConstantDiagonal(Mat Y, PetscScalar a)
    192: {
    193:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)Y->data;

    195:   PetscFunctionBegin;
    196:   ctx->diag *= a;
    197:   PetscFunctionReturn(PETSC_SUCCESS);
    198: }

    200: static PetscErrorCode MatZeroEntries_ConstantDiagonal(Mat Y)
    201: {
    202:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)Y->data;

    204:   PetscFunctionBegin;
    205:   ctx->diag = 0.0;
    206:   PetscFunctionReturn(PETSC_SUCCESS);
    207: }

    209: static PetscErrorCode MatSolve_ConstantDiagonal(Mat matin, Vec b, Vec x)
    210: {
    211:   Mat_ConstantDiagonal *ctx = (Mat_ConstantDiagonal *)matin->data;

    213:   PetscFunctionBegin;
    214:   if (ctx->diag == 0.0) matin->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
    215:   else matin->factorerrortype = MAT_FACTOR_NOERROR;
    216:   PetscCall(VecAXPBY(x, 1.0 / ctx->diag, 0.0, b));
    217:   PetscFunctionReturn(PETSC_SUCCESS);
    218: }

    220: static PetscErrorCode MatSOR_ConstantDiagonal(Mat matin, Vec x, PetscReal omega, MatSORType flag, PetscReal fshift, PetscInt its, PetscInt lits, Vec y)
    221: {
    222:   PetscFunctionBegin;
    223:   PetscCall(MatSolve_ConstantDiagonal(matin, x, y));
    224:   PetscFunctionReturn(PETSC_SUCCESS);
    225: }

    227: static PetscErrorCode MatGetInfo_ConstantDiagonal(Mat A, MatInfoType flag, MatInfo *info)
    228: {
    229:   PetscFunctionBegin;
    230:   info->block_size   = 1.0;
    231:   info->nz_allocated = 1.0;
    232:   info->nz_used      = 1.0;
    233:   info->nz_unneeded  = 0.0;
    234:   info->assemblies   = A->num_ass;
    235:   info->mallocs      = 0.0;
    236:   info->memory       = 0; /* REVIEW ME */
    237:   if (A->factortype) {
    238:     info->fill_ratio_given  = 1.0;
    239:     info->fill_ratio_needed = 1.0;
    240:     info->factor_mallocs    = 0.0;
    241:   } else {
    242:     info->fill_ratio_given  = 0;
    243:     info->fill_ratio_needed = 0;
    244:     info->factor_mallocs    = 0;
    245:   }
    246:   PetscFunctionReturn(PETSC_SUCCESS);
    247: }

    249: /*@
    250:   MatCreateConstantDiagonal - Creates a matrix with a uniform value along the diagonal

    252:   Collective

    254:   Input Parameters:
    255: + comm - MPI communicator
    256: . m    - number of local rows (or `PETSC_DECIDE` to have calculated if `M` is given)
    257:            This value should be the same as the local size used in creating the
    258:            y vector for the matrix-vector product y = Ax.
    259: . n    - This value should be the same as the local size used in creating the
    260:        x vector for the matrix-vector product y = Ax. (or `PETSC_DECIDE` to have
    261:        calculated if `N` is given) For square matrices n is almost always `m`.
    262: . M    - number of global rows (or `PETSC_DETERMINE` to have calculated if m is given)
    263: . N    - number of global columns (or `PETSC_DETERMINE` to have calculated if n is given)
    264: - diag - the diagonal value

    266:   Output Parameter:
    267: . J - the diagonal matrix

    269:   Level: advanced

    271:   Notes:
    272:   Only supports square matrices with the same number of local rows and columns

    274: .seealso: [](ch_matrices), `Mat`, `MatDestroy()`, `MATCONSTANTDIAGONAL`, `MatScale()`, `MatShift()`, `MatMult()`, `MatGetDiagonal()`, `MatGetFactor()`, `MatSolve()`
    275: @*/
    276: PetscErrorCode MatCreateConstantDiagonal(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt M, PetscInt N, PetscScalar diag, Mat *J)
    277: {
    278:   PetscFunctionBegin;
    279:   PetscCall(MatCreate(comm, J));
    280:   PetscCall(MatSetSizes(*J, m, n, M, N));
    281:   PetscCall(MatSetType(*J, MATCONSTANTDIAGONAL));
    282:   PetscCall(MatShift(*J, diag));
    283:   PetscCall(MatSetUp(*J));
    284:   PetscFunctionReturn(PETSC_SUCCESS);
    285: }

    287: /*MC
    288:    MATCONSTANTDIAGONAL - "constant-diagonal" - A diagonal matrix type with a uniform value
    289:    along the diagonal.

    291:   Level: advanced

    293: .seealso: [](ch_matrices), `Mat`, `MatCreateConstantDiagonal()`
    294: M*/
    295: PETSC_EXTERN PetscErrorCode MatCreate_ConstantDiagonal(Mat A)
    296: {
    297:   Mat_ConstantDiagonal *ctx;

    299:   PetscFunctionBegin;
    300:   PetscCall(PetscNew(&ctx));
    301:   ctx->diag = 0.0;
    302:   A->data   = (void *)ctx;

    304:   A->assembled                   = PETSC_TRUE;
    305:   A->preallocated                = PETSC_TRUE;
    306:   A->structurally_symmetric      = PETSC_BOOL3_TRUE;
    307:   A->structural_symmetry_eternal = PETSC_TRUE;
    308:   A->symmetric                   = PETSC_BOOL3_TRUE;
    309:   if (!PetscDefined(USE_COMPLEX)) A->hermitian = PETSC_BOOL3_TRUE;
    310:   A->symmetry_eternal = PETSC_TRUE;

    312:   A->ops->mult                      = MatMult_ConstantDiagonal;
    313:   A->ops->multadd                   = MatMultAdd_ConstantDiagonal;
    314:   A->ops->multtranspose             = MatMult_ConstantDiagonal;
    315:   A->ops->multtransposeadd          = MatMultAdd_ConstantDiagonal;
    316:   A->ops->multhermitiantranspose    = MatMultHermitianTranspose_ConstantDiagonal;
    317:   A->ops->multhermitiantransposeadd = MatMultHermitianTransposeAdd_ConstantDiagonal;
    318:   A->ops->solve                     = MatSolve_ConstantDiagonal;
    319:   A->ops->solvetranspose            = MatSolve_ConstantDiagonal;
    320:   A->ops->norm                      = MatNorm_ConstantDiagonal;
    321:   A->ops->createsubmatrices         = MatCreateSubMatrices_ConstantDiagonal;
    322:   A->ops->duplicate                 = MatDuplicate_ConstantDiagonal;
    323:   A->ops->missingdiagonal           = MatMissingDiagonal_ConstantDiagonal;
    324:   A->ops->getrow                    = MatGetRow_ConstantDiagonal;
    325:   A->ops->restorerow                = MatRestoreRow_ConstantDiagonal;
    326:   A->ops->sor                       = MatSOR_ConstantDiagonal;
    327:   A->ops->shift                     = MatShift_ConstantDiagonal;
    328:   A->ops->scale                     = MatScale_ConstantDiagonal;
    329:   A->ops->getdiagonal               = MatGetDiagonal_ConstantDiagonal;
    330:   A->ops->view                      = MatView_ConstantDiagonal;
    331:   A->ops->zeroentries               = MatZeroEntries_ConstantDiagonal;
    332:   A->ops->destroy                   = MatDestroy_ConstantDiagonal;
    333:   A->ops->getinfo                   = MatGetInfo_ConstantDiagonal;
    334:   A->ops->equal                     = MatEqual_ConstantDiagonal;
    335:   A->ops->axpy                      = MatAXPY_ConstantDiagonal;

    337:   PetscCall(PetscObjectChangeTypeName((PetscObject)A, MATCONSTANTDIAGONAL));
    338:   PetscFunctionReturn(PETSC_SUCCESS);
    339: }

    341: static PetscErrorCode MatFactorNumeric_ConstantDiagonal(Mat fact, Mat A, const MatFactorInfo *info)
    342: {
    343:   Mat_ConstantDiagonal *actx = (Mat_ConstantDiagonal *)A->data, *fctx = (Mat_ConstantDiagonal *)fact->data;

    345:   PetscFunctionBegin;
    346:   if (actx->diag == 0.0) fact->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
    347:   else fact->factorerrortype = MAT_FACTOR_NOERROR;
    348:   fctx->diag       = 1.0 / actx->diag;
    349:   fact->ops->solve = MatMult_ConstantDiagonal;
    350:   PetscFunctionReturn(PETSC_SUCCESS);
    351: }

    353: static PetscErrorCode MatFactorSymbolic_LU_ConstantDiagonal(Mat fact, Mat A, IS isrow, IS iscol, const MatFactorInfo *info)
    354: {
    355:   PetscFunctionBegin;
    356:   fact->ops->lufactornumeric = MatFactorNumeric_ConstantDiagonal;
    357:   PetscFunctionReturn(PETSC_SUCCESS);
    358: }

    360: static PetscErrorCode MatFactorSymbolic_Cholesky_ConstantDiagonal(Mat fact, Mat A, IS isrow, const MatFactorInfo *info)
    361: {
    362:   PetscFunctionBegin;
    363:   fact->ops->choleskyfactornumeric = MatFactorNumeric_ConstantDiagonal;
    364:   PetscFunctionReturn(PETSC_SUCCESS);
    365: }

    367: PETSC_INTERN PetscErrorCode MatGetFactor_constantdiagonal_petsc(Mat A, MatFactorType ftype, Mat *B)
    368: {
    369:   PetscInt n = A->rmap->n, N = A->rmap->N;

    371:   PetscFunctionBegin;
    372:   PetscCall(MatCreateConstantDiagonal(PetscObjectComm((PetscObject)A), n, n, N, N, 0, B));

    374:   (*B)->factortype                  = ftype;
    375:   (*B)->ops->ilufactorsymbolic      = MatFactorSymbolic_LU_ConstantDiagonal;
    376:   (*B)->ops->lufactorsymbolic       = MatFactorSymbolic_LU_ConstantDiagonal;
    377:   (*B)->ops->iccfactorsymbolic      = MatFactorSymbolic_Cholesky_ConstantDiagonal;
    378:   (*B)->ops->choleskyfactorsymbolic = MatFactorSymbolic_Cholesky_ConstantDiagonal;

    380:   (*B)->ops->shift       = NULL;
    381:   (*B)->ops->scale       = NULL;
    382:   (*B)->ops->mult        = NULL;
    383:   (*B)->ops->sor         = NULL;
    384:   (*B)->ops->zeroentries = NULL;

    386:   PetscCall(PetscFree((*B)->solvertype));
    387:   PetscCall(PetscStrallocpy(MATSOLVERPETSC, &(*B)->solvertype));
    388:   PetscFunctionReturn(PETSC_SUCCESS);
    389: }