Date: 2022-11-02T11:46:50+00:00

Actual source code: evsl.c
slepc-3.18.1 2022-11-02
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain

      6:    This file is part of SLEPc.
      7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
      8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      9: */
     10: /*
     11:    This file implements a wrapper to eigensolvers in EVSL.
     12: */

     14: #include <slepc/private/epsimpl.h>
     15: #include <evsl.h>

     17: #define PetscCallEVSL(func, ...) do {                                                   \
     18:     PetscStackPushExternal(PetscStringize(func));                                                      \
     19:     PetscErrorCode evsl_ierr_ = func(__VA_ARGS__);                                              \
     20:     PetscStackPop;                                                                             \
     22:   } while (0)

     24: typedef struct {
     25:   PetscBool         initialized;
     26:   Mat               A;           /* problem matrix */
     27:   Vec               x,y;         /* auxiliary vectors */
     28:   PetscReal         *sli;        /* slice bounds */
     29:   PetscInt          nev;         /* approximate number of wanted eigenvalues in each slice */
     30:   PetscLayout       map;         /* used to distribute slices among MPI processes */
     31:   PetscBool         estimrange;  /* the filter range was not set by the user */
     32:   /* user parameters */
     33:   PetscInt          nslices;     /* number of slices */
     34:   PetscReal         lmin,lmax;   /* numerical range (min and max eigenvalue) */
     35:   EPSEVSLDOSMethod  dos;         /* DOS method, either KPM or Lanczos */
     36:   PetscInt          nvec;        /* number of sample vectors used for DOS */
     37:   PetscInt          deg;         /* polynomial degree used for DOS (KPM only) */
     38:   PetscInt          steps;       /* number of Lanczos steps used for DOS (Lanczos only) */
     39:   PetscInt          npoints;     /* number of sample points used for DOS (Lanczos only) */
     40:   PetscInt          max_deg;     /* maximum degree allowed for the polynomial */
     41:   PetscReal         thresh;      /* threshold for accepting polynomial */
     42:   EPSEVSLDamping    damping;     /* type of damping (for polynomial and for DOS-KPM) */
     43: } EPS_EVSL;

     45: static void AMatvec_EVSL(double *xa,double *ya,void *data)
     46: {
     47:   EPS_EVSL       *ctx = (EPS_EVSL*)data;
     48:   Vec            x = ctx->x,y = ctx->y;
     49:   Mat            A = ctx->A;

     51:   PetscObjectComm((PetscObject)A),VecPlaceArray(x,(PetscScalar*)xa);
     52:   PetscObjectComm((PetscObject)A),VecPlaceArray(y,(PetscScalar*)ya);
     53:   PetscObjectComm((PetscObject)A),MatMult(A,x,y);
     54:   PetscObjectComm((PetscObject)A),VecResetArray(x);
     55:   PetscObjectComm((PetscObject)A),VecResetArray(y);
     56:   return;
     57: }

     59: PetscErrorCode EPSSetUp_EVSL(EPS eps)
     60: {
     61:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;
     62:   PetscMPIInt    size,rank;
     63:   PetscBool      isshift;
     64:   PetscScalar    *vinit;
     65:   PetscReal      *mu,ecount,xintv[4],*xdos,*ydos;
     66:   Vec            v0;
     67:   Mat            A;
     68:   PetscRandom    rnd;

     70:   EPSCheckStandard(eps);
     71:   EPSCheckHermitian(eps);
     72:   PetscObjectTypeCompare((PetscObject)eps->st,STSHIFT,&isshift);

     75:   if (ctx->initialized) EVSLFinish();
     76:   EVSLStart();
     77:   ctx->initialized=PETSC_TRUE;

     79:   /* get number of slices per process */
     80:   MPI_Comm_size(PetscObjectComm((PetscObject)eps),&size);
     81:   MPI_Comm_rank(PetscObjectComm((PetscObject)eps),&rank);
     82:   if (!ctx->nslices) ctx->nslices = size;
     83:   PetscLayoutDestroy(&ctx->map);
     84:   PetscLayoutCreateFromSizes(PetscObjectComm((PetscObject)eps),PETSC_DECIDE,ctx->nslices,1,&ctx->map);

     86:   /* get matrix and prepare auxiliary vectors */
     87:   MatDestroy(&ctx->A);
     88:   STGetMatrix(eps->st,0,&A);
     89:   if (size==1) {
     90:     PetscObjectReference((PetscObject)A);
     91:     ctx->A = A;
     92:   } else MatCreateRedundantMatrix(A,0,PETSC_COMM_SELF,MAT_INITIAL_MATRIX,&ctx->A);
     93:   SetAMatvec(eps->n,&AMatvec_EVSL,(void*)ctx);
     94:   if (!ctx->x) MatCreateVecsEmpty(ctx->A,&ctx->x,&ctx->y);
     95:   EPSCheckUnsupported(eps,EPS_FEATURE_ARBITRARY | EPS_FEATURE_REGION | EPS_FEATURE_STOPPING);
     96:   EPSCheckIgnored(eps,EPS_FEATURE_EXTRACTION | EPS_FEATURE_CONVERGENCE);

     98:   if (!eps->which) eps->which=EPS_ALL;

    101:   /* estimate numerical range */
    102:   if (ctx->estimrange || ctx->lmin == PETSC_MIN_REAL || ctx->lmax == PETSC_MAX_REAL) {
    103:     MatCreateVecs(ctx->A,&v0,NULL);
    104:     if (!eps->V) EPSGetBV(eps,&eps->V);
    105:     BVGetRandomContext(eps->V,&rnd);
    106:     VecSetRandom(v0,rnd);
    107:     VecGetArray(v0,&vinit);
    108:     PetscCallEVSL(LanTrbounds,50,200,eps->tol,vinit,1,&ctx->lmin,&ctx->lmax,NULL);
    109:     VecRestoreArray(v0,&vinit);
    110:     VecDestroy(&v0);
    111:     ctx->estimrange = PETSC_TRUE;   /* estimate if called again with another matrix */
    112:   }
    114:   xintv[0] = eps->inta;
    115:   xintv[1] = eps->intb;
    116:   xintv[2] = ctx->lmin;
    117:   xintv[3] = ctx->lmax;

    119:   /* estimate number of eigenvalues in the interval */
    120:   switch (ctx->dos) {
    121:     case EPS_EVSL_DOS_KPM:
    122:       PetscMalloc1(ctx->deg+1,&mu);
    123:       if (!rank) PetscCallEVSL(kpmdos,ctx->deg,(int)ctx->damping,ctx->nvec,xintv,mu,&ecount);
    124:       MPI_Bcast(mu,ctx->deg+1,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));
    125:       break;
    126:     case EPS_EVSL_DOS_LANCZOS:
    127:       PetscMalloc2(ctx->npoints,&xdos,ctx->npoints,&ydos);
    128:       if (!rank) PetscCallEVSL(LanDos,ctx->nvec,PetscMin(ctx->steps,eps->n/2),ctx->npoints,xdos,ydos,&ecount,xintv);
    129:       MPI_Bcast(xdos,ctx->npoints,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));
    130:       MPI_Bcast(ydos,ctx->npoints,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));
    131:       break;
    132:     default:
    133:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid DOS method");
    134:   }
    135:   MPI_Bcast(&ecount,1,MPIU_REAL,0,PetscObjectComm((PetscObject)eps));

    137:   PetscInfo(eps,"Estimated eigenvalue count in the interval: %g\n",ecount);
    138:   eps->ncv = (PetscInt)PetscCeilReal(1.5*ecount);

    140:   /* slice the spectrum */
    141:   PetscFree(ctx->sli);
    142:   PetscMalloc1(ctx->nslices+1,&ctx->sli);
    143:   if (ctx->dos == EPS_EVSL_DOS_KPM) {
    144:     PetscCallEVSL(spslicer,ctx->sli,mu,ctx->deg,xintv,ctx->nslices,10*(PetscInt)ecount);
    145:     PetscFree(mu);
    146:   } else if (ctx->dos == EPS_EVSL_DOS_LANCZOS) {
    147:     spslicer2(xdos,ydos,ctx->nslices,ctx->npoints,ctx->sli);
    148:     PetscFree2(xdos,ydos);
    149:   }

    151:   /* approximate number of eigenvalues wanted in each slice */
    152:   ctx->nev = (PetscInt)(1.0 + ecount/(PetscReal)ctx->nslices) + 2;

    154:   if (eps->mpd!=PETSC_DEFAULT) PetscInfo(eps,"Warning: parameter mpd ignored\n");
    155:   if (eps->max_it==PETSC_DEFAULT) eps->max_it = 1;
    156:   EPSAllocateSolution(eps,0);
    157:   return 0;
    158: }

    160: PetscErrorCode EPSSolve_EVSL(EPS eps)
    161: {
    162:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;
    163:   PetscInt       i,j,k=0,sl,mlan,nevout,*ind,nevmax,rstart,rend,*nevloc,*disp,N;
    164:   PetscReal      *res,xintv[4],*errest;
    165:   PetscScalar    *lam,*X,*Y,*vinit,*eigr;
    166:   PetscMPIInt    size,rank;
    167:   PetscRandom    rnd;
    168:   Vec            v,w,v0,x;
    169:   VecScatter     vs;
    170:   IS             is;
    171:   polparams      pol;

    173:   MPI_Comm_size(PetscObjectComm((PetscObject)eps),&size);
    174:   MPI_Comm_rank(PetscObjectComm((PetscObject)eps),&rank);
    175:   PetscLayoutGetRange(ctx->map,&rstart,&rend);
    176:   nevmax = (rend-rstart)*ctx->nev;
    177:   MatCreateVecs(ctx->A,&v0,NULL);
    178:   BVGetRandomContext(eps->V,&rnd);
    179:   VecSetRandom(v0,rnd);
    180:   VecGetArray(v0,&vinit);
    181:   PetscMalloc5(size,&nevloc,size+1,&disp,nevmax,&eigr,nevmax,&errest,nevmax*eps->n,&X);
    182:   mlan = PetscMin(PetscMax(5*ctx->nev,300),eps->n);
    183:   for (sl=rstart; sl<rend; sl++) {
    184:     xintv[0] = ctx->sli[sl];
    185:     xintv[1] = ctx->sli[sl+1];
    186:     xintv[2] = ctx->lmin;
    187:     xintv[3] = ctx->lmax;
    188:     PetscInfo(ctx->A,"Subinterval %" PetscInt_FMT ": [%.4e, %.4e]\n",sl+1,xintv[0],xintv[1]);
    189:     set_pol_def(&pol);
    190:     pol.max_deg    = ctx->max_deg;
    191:     pol.damping    = (int)ctx->damping;
    192:     pol.thresh_int = ctx->thresh;
    193:     find_pol(xintv,&pol);
    194:     PetscInfo(ctx->A,"Polynomial [type = %" PetscInt_FMT "], deg %" PetscInt_FMT ", bar %e gam %e\n",pol.type,pol.deg,pol.bar,pol.gam);
    195:     PetscCallEVSL(ChebLanNr,xintv,mlan,eps->tol,vinit,&pol,&nevout,&lam,&Y,&res,NULL);
    197:     free_pol(&pol);
    198:     PetscInfo(ctx->A,"Computed %" PetscInt_FMT " eigenvalues\n",nevout);
    199:     PetscMalloc1(nevout,&ind);
    200:     sort_double(nevout,lam,ind);
    201:     for (i=0;i<nevout;i++) {
    202:       eigr[i+k]   = lam[i];
    203:       errest[i+k] = res[ind[i]];
    204:       PetscArraycpy(X+(i+k)*eps->n,Y+ind[i]*eps->n,eps->n);
    205:     }
    206:     k += nevout;
    207:     if (lam) evsl_Free(lam);
    208:     if (Y)   evsl_Free_device(Y);
    209:     if (res) evsl_Free(res);
    210:     PetscFree(ind);
    211:   }
    212:   VecRestoreArray(v0,&vinit);
    213:   VecDestroy(&v0);

    215:   /* gather eigenvalues computed by each MPI process */
    216:   MPI_Allgather(&k,1,MPIU_INT,nevloc,1,MPIU_INT,PetscObjectComm((PetscObject)eps));
    217:   eps->nev = nevloc[0];
    218:   disp[0]  = 0;
    219:   for (i=1;i<size;i++) {
    220:     eps->nev += nevloc[i];
    221:     disp[i]   = disp[i-1]+nevloc[i-1];
    222:   }
    223:   disp[size] = disp[size-1]+nevloc[size-1];
    225:   MPI_Allgatherv(eigr,k,MPIU_SCALAR,eps->eigr,nevloc,disp,MPIU_SCALAR,PetscObjectComm((PetscObject)eps));
    226:   MPI_Allgatherv(errest,k,MPIU_REAL,eps->errest,nevloc,disp,MPIU_REAL,PetscObjectComm((PetscObject)eps));
    227:   eps->nconv  = eps->nev;
    228:   eps->its    = 1;
    229:   eps->reason = EPS_CONVERGED_TOL;

    231:   /* scatter computed eigenvectors and store them in eps->V */
    232:   BVCreateVec(eps->V,&w);
    233:   for (i=0;i<size;i++) {
    234:     N = (rank==i)? eps->n: 0;
    235:     VecCreateSeq(PETSC_COMM_SELF,N,&x);
    236:     VecSetFromOptions(x);
    237:     ISCreateStride(PETSC_COMM_SELF,N,0,1,&is);
    238:     VecScatterCreate(x,is,w,is,&vs);
    239:     ISDestroy(&is);
    240:     for (j=disp[i];j<disp[i+1];j++) {
    241:       BVGetColumn(eps->V,j,&v);
    242:       if (rank==i) VecPlaceArray(x,X+(j-disp[i])*eps->n);
    243:       VecScatterBegin(vs,x,v,INSERT_VALUES,SCATTER_FORWARD);
    244:       VecScatterEnd(vs,x,v,INSERT_VALUES,SCATTER_FORWARD);
    245:       if (rank==i) VecResetArray(x);
    246:       BVRestoreColumn(eps->V,j,&v);
    247:     }
    248:     VecScatterDestroy(&vs);
    249:     VecDestroy(&x);
    250:   }
    251:   VecDestroy(&w);
    252:   PetscFree5(nevloc,disp,eigr,errest,X);
    253:   return 0;
    254: }

    256: static PetscErrorCode EPSEVSLSetSlices_EVSL(EPS eps,PetscInt nslices)
    257: {
    258:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

    260:   if (nslices == PETSC_DECIDE || nslices == PETSC_DEFAULT) nslices = 0;
    262:   if (ctx->nslices != nslices) {
    263:     ctx->nslices = nslices;
    264:     eps->state   = EPS_STATE_INITIAL;
    265:   }
    266:   return 0;
    267: }

    269: /*@
    270:    EPSEVSLSetSlices - Set the number of slices in which the interval must be
    271:    subdivided.

    273:    Logically Collective on eps

    275:    Input Parameters:
    276: +  eps     - the eigensolver context
    277: -  nslices - the number of slices

    279:    Options Database Key:
    280: .  -eps_evsl_slices <n> - set the number of slices to n

    282:    Notes:
    283:    By default, one slice per MPI process is used. Depending on the number of
    284:    eigenvalues, using more slices may be beneficial, but very narrow subintervals
    285:    imply higher polynomial degree.

    287:    Level: intermediate

    289: .seealso: EPSEVSLGetSlices()
    290: @*/
    291: PetscErrorCode EPSEVSLSetSlices(EPS eps,PetscInt nslices)
    292: {
    295:   PetscTryMethod(eps,"EPSEVSLSetSlices_C",(EPS,PetscInt),(eps,nslices));
    296:   return 0;
    297: }

    299: static PetscErrorCode EPSEVSLGetSlices_EVSL(EPS eps,PetscInt *nslices)
    300: {
    301:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

    303:   *nslices = ctx->nslices;
    304:   return 0;
    305: }

    307: /*@
    308:    EPSEVSLGetSlices - Gets the number of slices in which the interval must be
    309:    subdivided.

    311:    Not Collective

    313:    Input Parameter:
    314: .  eps - the eigensolver context

    316:    Output Parameter:
    317: .  nslices - the number of slices

    319:    Level: intermediate

    321: .seealso: EPSEVSLSetSlices()
    322: @*/
    323: PetscErrorCode EPSEVSLGetSlices(EPS eps,PetscInt *nslices)
    324: {
    327:   PetscUseMethod(eps,"EPSEVSLGetSlices_C",(EPS,PetscInt*),(eps,nslices));
    328:   return 0;
    329: }

    331: static PetscErrorCode EPSEVSLSetRange_EVSL(EPS eps,PetscReal lmin,PetscReal lmax)
    332: {
    333:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

    336:   if (ctx->lmin != lmin || ctx->lmax != lmax) {
    337:     ctx->lmin  = lmin;
    338:     ctx->lmax  = lmax;
    339:     eps->state = EPS_STATE_INITIAL;
    340:   }
    341:   return 0;
    342: }

    344: /*@
    345:    EPSEVSLSetRange - Defines the numerical range (or field of values) of the problem,
    346:    that is, the interval containing all eigenvalues.

    348:    Logically Collective on eps

    350:    Input Parameters:
    351: +  eps  - the eigensolver context
    352: .  lmin - left end of the interval
    353: -  lmax - right end of the interval

    355:    Options Database Key:
    356: .  -eps_evsl_range <a,b> - set [a,b] as the numerical range

    358:    Notes:
    359:    The filter will be most effective if the numerical range is tight, that is, lmin
    360:    and lmax are good approximations to the leftmost and rightmost eigenvalues,
    361:    respectively. If not set by the user, an approximation is computed internally.

    363:    The wanted computational interval specified via EPSSetInterval() must be
    364:    contained in the numerical range.

    366:    Level: intermediate

    368: .seealso: EPSEVSLGetRange(), EPSSetInterval()
    369: @*/
    370: PetscErrorCode EPSEVSLSetRange(EPS eps,PetscReal lmin,PetscReal lmax)
    371: {
    375:   PetscTryMethod(eps,"EPSEVSLSetRange_C",(EPS,PetscReal,PetscReal),(eps,lmin,lmax));
    376:   return 0;
    377: }

    379: static PetscErrorCode EPSEVSLGetRange_EVSL(EPS eps,PetscReal *lmin,PetscReal *lmax)
    380: {
    381:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

    383:   if (lmin) *lmin = ctx->lmin;
    384:   if (lmax) *lmax = ctx->lmax;
    385:   return 0;
    386: }

    388: /*@
    389:    EPSEVSLGetRange - Gets the interval containing all eigenvalues.

    391:    Not Collective

    393:    Input Parameter:
    394: .  eps - the eigensolver context

    396:    Output Parameters:
    397: +  lmin - left end of the interval
    398: -  lmax - right end of the interval

    400:    Level: intermediate

    402: .seealso: EPSEVSLSetRange()
    403: @*/
    404: PetscErrorCode EPSEVSLGetRange(EPS eps,PetscReal *lmin,PetscReal *lmax)
    405: {
    407:   PetscUseMethod(eps,"EPSEVSLGetRange_C",(EPS,PetscReal*,PetscReal*),(eps,lmin,lmax));
    408:   return 0;
    409: }

    411: static PetscErrorCode EPSEVSLSetDOSParameters_EVSL(EPS eps,EPSEVSLDOSMethod dos,PetscInt nvec,PetscInt deg,PetscInt steps,PetscInt npoints)
    412: {
    413:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

    415:   ctx->dos = dos;
    416:   if (nvec == PETSC_DECIDE || nvec == PETSC_DEFAULT) ctx->nvec = 80;
    417:   else {
    419:     ctx->nvec = nvec;
    420:   }
    421:   switch (dos) {
    422:     case EPS_EVSL_DOS_KPM:
    423:       if (deg == PETSC_DECIDE || deg == PETSC_DEFAULT) ctx->deg = 300;
    424:       else {
    426:         ctx->deg = deg;
    427:       }
    428:       break;
    429:     case EPS_EVSL_DOS_LANCZOS:
    430:       if (steps == PETSC_DECIDE || steps == PETSC_DEFAULT) ctx->steps = 40;
    431:       else {
    433:         ctx->steps = steps;
    434:       }
    435:       if (npoints == PETSC_DECIDE || npoints == PETSC_DEFAULT) ctx->npoints = 200;
    436:       else {
    438:         ctx->npoints = npoints;
    439:       }
    440:       break;
    441:   }
    442:   eps->state = EPS_STATE_INITIAL;
    443:   return 0;
    444: }

    446: /*@
    447:    EPSEVSLSetDOSParameters - Defines the parameters used for computing the
    448:    density of states (DOS) in the EVSL solver.

    450:    Logically Collective on eps

    452:    Input Parameters:
    453: +  eps     - the eigensolver context
    454: .  dos     - DOS method, either KPM or Lanczos
    455: .  nvec    - number of sample vectors
    456: .  deg     - polynomial degree (KPM only)
    457: .  steps   - number of Lanczos steps (Lanczos only)
    458: -  npoints - number of sample points (Lanczos only)

    460:    Options Database Keys:
    461: +  -eps_evsl_dos_method <dos> - set the DOS method, either kpm or lanczos
    462: .  -eps_evsl_dos_nvec <n> - set the number of sample vectors
    463: .  -eps_evsl_dos_degree <n> - set the polynomial degree
    464: .  -eps_evsl_dos_steps <n> - set the number of Lanczos steps
    465: -  -eps_evsl_dos_npoints <n> - set the number of sample points

    467:    Notes:
    468:    The density of states (or spectral density) can be approximated with two
    469:    methods, kernel polynomial method (KPM) or Lanczos. Some parameters for
    470:    these methods can be set by the user with this function, with some of
    471:    them being relevant for one of the methods only.

    473:    Level: intermediate

    475: .seealso: EPSEVSLGetDOSParameters()
    476: @*/
    477: PetscErrorCode EPSEVSLSetDOSParameters(EPS eps,EPSEVSLDOSMethod dos,PetscInt nvec,PetscInt deg,PetscInt steps,PetscInt npoints)
    478: {
    485:   PetscTryMethod(eps,"EPSEVSLSetDOSParameters_C",(EPS,EPSEVSLDOSMethod,PetscInt,PetscInt,PetscInt,PetscInt),(eps,dos,nvec,deg,steps,npoints));
    486:   return 0;
    487: }

    489: static PetscErrorCode EPSEVSLGetDOSParameters_EVSL(EPS eps,EPSEVSLDOSMethod *dos,PetscInt *nvec,PetscInt *deg,PetscInt *steps,PetscInt *npoints)
    490: {
    491:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

    493:   if (dos)     *dos     = ctx->dos;
    494:   if (nvec)    *nvec    = ctx->nvec;
    495:   if (deg)     *deg     = ctx->deg;
    496:   if (steps)   *steps   = ctx->steps;
    497:   if (npoints) *npoints = ctx->npoints;
    498:   return 0;
    499: }

    501: /*@
    502:    EPSEVSLGetDOSParameters - Gets the parameters used for computing the
    503:    density of states (DOS) in the EVSL solver.

    505:    Not Collective

    507:    Input Parameter:
    508: .  eps - the eigensolver context

    510:    Output Parameters:
    511: +  dos     - DOS method, either KPM or Lanczos
    512: .  nvec    - number of sample vectors
    513: .  deg     - polynomial degree (KPM only)
    514: .  steps   - number of Lanczos steps (Lanczos only)
    515: -  npoints - number of sample points (Lanczos only)

    517:    Level: intermediate

    519: .seealso: EPSEVSLSetDOSParameters()
    520: @*/
    521: PetscErrorCode EPSEVSLGetDOSParameters(EPS eps,EPSEVSLDOSMethod *dos,PetscInt *nvec,PetscInt *deg,PetscInt *steps,PetscInt *npoints)
    522: {
    524:   PetscUseMethod(eps,"EPSEVSLGetDOSParameters_C",(EPS,EPSEVSLDOSMethod*,PetscInt*,PetscInt*,PetscInt*,PetscInt*),(eps,dos,nvec,deg,steps,npoints));
    525:   return 0;
    526: }

    528: static PetscErrorCode EPSEVSLSetPolParameters_EVSL(EPS eps,PetscInt max_deg,PetscReal thresh)
    529: {
    530:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

    532:   if (max_deg == PETSC_DECIDE || max_deg == PETSC_DEFAULT) ctx->max_deg = 10000;
    533:   else {
    535:     ctx->max_deg = max_deg;
    536:   }
    537:   if (thresh == PETSC_DECIDE || thresh == PETSC_DEFAULT) ctx->thresh = 0.8;
    538:   else {
    540:     ctx->thresh = thresh;
    541:   }
    542:   eps->state = EPS_STATE_INITIAL;
    543:   return 0;
    544: }

    546: /*@
    547:    EPSEVSLSetPolParameters - Defines the parameters used for building the
    548:    building the polynomial in the EVSL solver.

    550:    Logically Collective on eps

    552:    Input Parameters:
    553: +  eps     - the eigensolver context
    554: .  max_deg - maximum degree allowed for the polynomial
    555: -  thresh  - threshold for accepting polynomial

    557:    Options Database Keys:
    558: +  -eps_evsl_pol_max_deg <d> - set maximum polynomial degree
    559: -  -eps_evsl_pol_thresh <t> - set the threshold

    561:    Level: intermediate

    563: .seealso: EPSEVSLGetPolParameters()
    564: @*/
    565: PetscErrorCode EPSEVSLSetPolParameters(EPS eps,PetscInt max_deg,PetscReal thresh)
    566: {
    570:   PetscTryMethod(eps,"EPSEVSLSetPolParameters_C",(EPS,PetscInt,PetscReal),(eps,max_deg,thresh));
    571:   return 0;
    572: }

    574: static PetscErrorCode EPSEVSLGetPolParameters_EVSL(EPS eps,PetscInt *max_deg,PetscReal *thresh)
    575: {
    576:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

    578:   if (max_deg) *max_deg = ctx->max_deg;
    579:   if (thresh)  *thresh  = ctx->thresh;
    580:   return 0;
    581: }

    583: /*@
    584:    EPSEVSLGetPolParameters - Gets the parameters used for building the
    585:    polynomial in the EVSL solver.

    587:    Not Collective

    589:    Input Parameter:
    590: .  eps - the eigensolver context

    592:    Output Parameters:
    593: +  max_deg - the maximum degree of the polynomial
    594: -  thresh  - the threshold

    596:    Level: intermediate

    598: .seealso: EPSEVSLSetPolParameters()
    599: @*/
    600: PetscErrorCode EPSEVSLGetPolParameters(EPS eps,PetscInt *max_deg,PetscReal *thresh)
    601: {
    603:   PetscUseMethod(eps,"EPSEVSLGetPolParameters_C",(EPS,PetscInt*,PetscReal*),(eps,max_deg,thresh));
    604:   return 0;
    605: }

    607: static PetscErrorCode EPSEVSLSetDamping_EVSL(EPS eps,EPSEVSLDamping damping)
    608: {
    609:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

    611:   if (ctx->damping != damping) {
    612:     ctx->damping = damping;
    613:     eps->state   = EPS_STATE_INITIAL;
    614:   }
    615:   return 0;
    616: }

    618: /*@
    619:    EPSEVSLSetDamping - Set the type of damping to be used in EVSL.

    621:    Logically Collective on eps

    623:    Input Parameters:
    624: +  eps     - the eigensolver context
    625: -  damping - the type of damping

    627:    Options Database Key:
    628: .  -eps_evsl_damping <n> - set the type of damping

    630:    Notes:
    631:    Damping is applied when building the polynomial to be used when solving the
    632:    eigenproblem, and also during estimation of DOS with the KPM method.

    634:    Level: intermediate

    636: .seealso: EPSEVSLGetDamping(), EPSEVSLSetDOSParameters()
    637: @*/
    638: PetscErrorCode EPSEVSLSetDamping(EPS eps,EPSEVSLDamping damping)
    639: {
    642:   PetscTryMethod(eps,"EPSEVSLSetDamping_C",(EPS,EPSEVSLDamping),(eps,damping));
    643:   return 0;
    644: }

    646: static PetscErrorCode EPSEVSLGetDamping_EVSL(EPS eps,EPSEVSLDamping *damping)
    647: {
    648:   EPS_EVSL *ctx = (EPS_EVSL*)eps->data;

    650:   *damping = ctx->damping;
    651:   return 0;
    652: }

    654: /*@
    655:    EPSEVSLGetDamping - Gets the type of damping.

    657:    Not Collective

    659:    Input Parameter:
    660: .  eps - the eigensolver context

    662:    Output Parameter:
    663: .  damping - the type of damping

    665:    Level: intermediate

    667: .seealso: EPSEVSLSetDamping()
    668: @*/
    669: PetscErrorCode EPSEVSLGetDamping(EPS eps,EPSEVSLDamping *damping)
    670: {
    673:   PetscUseMethod(eps,"EPSEVSLGetDamping_C",(EPS,EPSEVSLDamping*),(eps,damping));
    674:   return 0;
    675: }

    677: PetscErrorCode EPSView_EVSL(EPS eps,PetscViewer viewer)
    678: {
    679:   PetscBool      isascii;
    680:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;

    682:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);
    683:   if (isascii) {
    684:     PetscViewerASCIIPrintf(viewer,"  numerical range = [%g,%g]\n",(double)ctx->lmin,(double)ctx->lmax);
    685:     PetscViewerASCIIPrintf(viewer,"  number of slices = %" PetscInt_FMT "\n",ctx->nslices);
    686:     PetscViewerASCIIPrintf(viewer,"  type of damping = %s\n",EPSEVSLDampings[ctx->damping]);
    687:     PetscViewerASCIIPrintf(viewer,"  computing DOS with %s: nvec=%" PetscInt_FMT ", ",EPSEVSLDOSMethods[ctx->dos],ctx->nvec);
    688:     PetscViewerASCIIUseTabs(viewer,PETSC_FALSE);
    689:     switch (ctx->dos) {
    690:       case EPS_EVSL_DOS_KPM:
    691:         PetscViewerASCIIPrintf(viewer,"degree=%" PetscInt_FMT "\n",ctx->deg);
    692:         break;
    693:       case EPS_EVSL_DOS_LANCZOS:
    694:         PetscViewerASCIIPrintf(viewer,"steps=%" PetscInt_FMT ", npoints=%" PetscInt_FMT "\n",ctx->steps,ctx->npoints);
    695:         break;
    696:     }
    697:     PetscViewerASCIIUseTabs(viewer,PETSC_TRUE);
    698:     PetscViewerASCIIPrintf(viewer,"  polynomial parameters: max degree = %" PetscInt_FMT ", threshold = %g\n",ctx->max_deg,(double)ctx->thresh);
    699:   }
    700:   return 0;
    701: }

    703: PetscErrorCode EPSSetFromOptions_EVSL(EPS eps,PetscOptionItems *PetscOptionsObject)
    704: {
    705:   PetscReal        array[2]={0,0},th;
    706:   PetscInt         k,i1,i2,i3,i4;
    707:   PetscBool        flg,flg1;
    708:   EPSEVSLDOSMethod dos;
    709:   EPSEVSLDamping   damping;
    710:   EPS_EVSL         *ctx = (EPS_EVSL*)eps->data;

    712:   PetscOptionsHeadBegin(PetscOptionsObject,"EPS EVSL Options");

    714:     k = 2;
    715:     PetscOptionsRealArray("-eps_evsl_range","Interval containing all eigenvalues (two real values separated with a comma without spaces)","EPSEVSLSetRange",array,&k,&flg);
    716:     if (flg) {
    718:       EPSEVSLSetRange(eps,array[0],array[1]);
    719:     }

    721:     PetscOptionsInt("-eps_evsl_slices","Number of slices","EPSEVSLSetSlices",ctx->nslices,&i1,&flg);
    722:     if (flg) EPSEVSLSetSlices(eps,i1);

    724:     PetscOptionsEnum("-eps_evsl_damping","Type of damping","EPSEVSLSetDamping",EPSEVSLDampings,(PetscEnum)ctx->damping,(PetscEnum*)&damping,&flg);
    725:     if (flg) EPSEVSLSetDamping(eps,damping);

    727:     EPSEVSLGetDOSParameters(eps,&dos,&i1,&i2,&i3,&i4);
    728:     PetscOptionsEnum("-eps_evsl_dos_method","Method to compute the DOS","EPSEVSLSetDOSParameters",EPSEVSLDOSMethods,(PetscEnum)ctx->dos,(PetscEnum*)&dos,&flg);
    729:     PetscOptionsInt("-eps_evsl_dos_nvec","Number of sample vectors for DOS","EPSEVSLSetDOSParameters",i1,&i1,&flg1);
    730:     if (flg1) flg = PETSC_TRUE;
    731:     PetscOptionsInt("-eps_evsl_dos_degree","Polynomial degree used for DOS","EPSEVSLSetDOSParameters",i2,&i2,&flg1);
    732:     if (flg1) flg = PETSC_TRUE;
    733:     PetscOptionsInt("-eps_evsl_dos_steps","Number of Lanczos steps in DOS","EPSEVSLSetDOSParameters",i3,&i3,&flg1);
    734:     if (flg1) flg = PETSC_TRUE;
    735:     PetscOptionsInt("-eps_evsl_dos_npoints","Number of sample points used for DOS","EPSEVSLSetDOSParameters",i4,&i4,&flg1);
    736:     if (flg || flg1) EPSEVSLSetDOSParameters(eps,dos,i1,i2,i3,i4);

    738:     EPSEVSLGetPolParameters(eps,&i1,&th);
    739:     PetscOptionsInt("-eps_evsl_pol_max_deg","Maximum degree allowed for the polynomial","EPSEVSLSetPolParameters",i1,&i1,&flg);
    740:     PetscOptionsReal("-eps_evsl_pol_threshold","Threshold for accepting polynomial","EPSEVSLSetPolParameters",th,&th,&flg1);
    741:     if (flg || flg1) EPSEVSLSetPolParameters(eps,i1,th);

    743:   PetscOptionsHeadEnd();
    744:   return 0;
    745: }

    747: PetscErrorCode EPSDestroy_EVSL(EPS eps)
    748: {
    749:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;

    751:   if (ctx->initialized) EVSLFinish();
    752:   PetscLayoutDestroy(&ctx->map);
    753:   PetscFree(ctx->sli);
    754:   PetscFree(eps->data);
    755:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetRange_C",NULL);
    756:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetRange_C",NULL);
    757:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetSlices_C",NULL);
    758:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetSlices_C",NULL);
    759:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDOSParameters_C",NULL);
    760:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDOSParameters_C",NULL);
    761:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetPolParameters_C",NULL);
    762:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetPolParameters_C",NULL);
    763:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDamping_C",NULL);
    764:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDamping_C",NULL);
    765:   return 0;
    766: }

    768: PetscErrorCode EPSReset_EVSL(EPS eps)
    769: {
    770:   EPS_EVSL       *ctx = (EPS_EVSL*)eps->data;

    772:   MatDestroy(&ctx->A);
    773:   VecDestroy(&ctx->x);
    774:   VecDestroy(&ctx->y);
    775:   return 0;
    776: }

    778: SLEPC_EXTERN PetscErrorCode EPSCreate_EVSL(EPS eps)
    779: {
    780:   EPS_EVSL       *ctx;

    782:   PetscNew(&ctx);
    783:   eps->data = (void*)ctx;

    785:   ctx->nslices = 0;
    786:   ctx->lmin    = PETSC_MIN_REAL;
    787:   ctx->lmax    = PETSC_MAX_REAL;
    788:   ctx->dos     = EPS_EVSL_DOS_KPM;
    789:   ctx->nvec    = 80;
    790:   ctx->deg     = 300;
    791:   ctx->steps   = 40;
    792:   ctx->npoints = 200;
    793:   ctx->max_deg = 10000;
    794:   ctx->thresh  = 0.8;
    795:   ctx->damping = EPS_EVSL_DAMPING_SIGMA;

    797:   eps->categ = EPS_CATEGORY_OTHER;

    799:   eps->ops->solve          = EPSSolve_EVSL;
    800:   eps->ops->setup          = EPSSetUp_EVSL;
    801:   eps->ops->setupsort      = EPSSetUpSort_Basic;
    802:   eps->ops->setfromoptions = EPSSetFromOptions_EVSL;
    803:   eps->ops->destroy        = EPSDestroy_EVSL;
    804:   eps->ops->reset          = EPSReset_EVSL;
    805:   eps->ops->view           = EPSView_EVSL;
    806:   eps->ops->backtransform  = EPSBackTransform_Default;
    807:   eps->ops->setdefaultst   = EPSSetDefaultST_NoFactor;

    809:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetRange_C",EPSEVSLSetRange_EVSL);
    810:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetRange_C",EPSEVSLGetRange_EVSL);
    811:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetSlices_C",EPSEVSLSetSlices_EVSL);
    812:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetSlices_C",EPSEVSLGetSlices_EVSL);
    813:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDOSParameters_C",EPSEVSLSetDOSParameters_EVSL);
    814:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDOSParameters_C",EPSEVSLGetDOSParameters_EVSL);
    815:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetPolParameters_C",EPSEVSLSetPolParameters_EVSL);
    816:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetPolParameters_C",EPSEVSLGetPolParameters_EVSL);
    817:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLSetDamping_C",EPSEVSLSetDamping_EVSL);
    818:   PetscObjectComposeFunction((PetscObject)eps,"EPSEVSLGetDamping_C",EPSEVSLGetDamping_EVSL);
    819:   return 0;
    820: }