Date: 2021-09-20T09:43:51+00:00

Actual source code: davidson.c
slepc-3.15.2 2021-09-20
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2021, 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:    Skeleton of Davidson solver. Actual solvers are GD and JD.

     13:    References:

     15:        [1] E. Romero and J.E. Roman, "A parallel implementation of Davidson
     16:            methods for large-scale eigenvalue problems in SLEPc", ACM Trans.
     17:            Math. Software 40(2):13, 2014.
     18: */

     20: #include "davidson.h"

     22: static PetscBool  cited = PETSC_FALSE;
     23: static const char citation[] =
     24:   "@Article{slepc-davidson,\n"
     25:   "   author = \"E. Romero and J. E. Roman\",\n"
     26:   "   title = \"A parallel implementation of {Davidson} methods for large-scale eigenvalue problems in {SLEPc}\",\n"
     27:   "   journal = \"{ACM} Trans. Math. Software\",\n"
     28:   "   volume = \"40\",\n"
     29:   "   number = \"2\",\n"
     30:   "   pages = \"13:1--13:29\",\n"
     31:   "   year = \"2014,\"\n"
     32:   "   doi = \"https://doi.org/10.1145/2543696\"\n"
     33:   "}\n";

     35: PetscErrorCode EPSSetUp_XD(EPS eps)
     36: {
     38:   EPS_DAVIDSON   *data = (EPS_DAVIDSON*)eps->data;
     39:   dvdDashboard   *dvd = &data->ddb;
     40:   dvdBlackboard  b;
     41:   PetscInt       min_size_V,bs,initv,nmat;
     42:   Mat            A,B;
     43:   KSP            ksp;
     44:   PetscBool      ipB,ispositive;
     45:   HarmType_t     harm;
     46:   InitType_t     init;
     47:   PetscScalar    target;

     50:   /* Setup EPS options and get the problem specification */
     51:   bs = data->blocksize;
     52:   if (bs <= 0) bs = 1;
     53:   if (eps->ncv!=PETSC_DEFAULT) {
     54:     if (eps->ncv<eps->nev) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The value of ncv must be at least nev");
     55:   } else if (eps->mpd!=PETSC_DEFAULT) eps->ncv = eps->mpd + eps->nev + bs;
     56:   else if (eps->nev<500) eps->ncv = PetscMin(eps->n-bs,PetscMax(2*eps->nev,eps->nev+15))+bs;
     57:   else eps->ncv = PetscMin(eps->n-bs,eps->nev+500)+bs;
     58:   if (eps->mpd==PETSC_DEFAULT) eps->mpd = eps->ncv;
     59:   if (eps->mpd > eps->ncv) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The mpd has to be less or equal than ncv");
     60:   if (eps->mpd < 2) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The mpd has to be greater than 2");
     61:   if (eps->max_it==PETSC_DEFAULT) eps->max_it = PetscMax(100*eps->ncv,2*eps->n);
     62:   if (!eps->which) eps->which = EPS_LARGEST_MAGNITUDE;
     63:   if (!(eps->nev + bs <= eps->ncv)) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The ncv has to be greater than nev plus blocksize");
     64:   if (eps->trueres) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"-eps_true_residual is temporally disable in this solver.");
     65:   EPSCheckUnsupported(eps,EPS_FEATURE_REGION | EPS_FEATURE_TWOSIDED);

     67:   EPSXDSetRestart_XD(eps,data->minv,data->plusk);
     68:   min_size_V = data->minv;
     69:   if (!min_size_V) min_size_V = PetscMin(PetscMax(bs,5),eps->mpd/2);
     70:   if (!(min_size_V+bs <= eps->mpd)) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The value of minv must be less than mpd minus blocksize");
     71:   initv = data->initialsize;
     72:   if (eps->mpd < initv) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The initv has to be less or equal than mpd");

     74:   /* Change the default sigma to inf if necessary */
     75:   if (eps->which == EPS_LARGEST_MAGNITUDE || eps->which == EPS_LARGEST_REAL || eps->which == EPS_LARGEST_IMAGINARY) {
     76:     STSetDefaultShift(eps->st,PETSC_MAX_REAL);
     77:   }

     79:   /* Set up preconditioner */
     80:   STSetUp(eps->st);

     82:   /* Setup problem specification in dvd */
     83:   STGetNumMatrices(eps->st,&nmat);
     84:   STGetMatrix(eps->st,0,&A);
     85:   if (nmat>1) { STGetMatrix(eps->st,1,&B); }
     86:   EPSReset_XD(eps);
     87:   PetscMemzero(dvd,sizeof(dvdDashboard));
     88:   dvd->A = A; dvd->B = eps->isgeneralized? B: NULL;
     89:   ispositive = eps->ispositive;
     90:   dvd->sA = DVD_MAT_IMPLICIT | (eps->ishermitian? DVD_MAT_HERMITIAN: 0) | ((ispositive && !eps->isgeneralized) ? DVD_MAT_POS_DEF: 0);
     91:   /* Asume -eps_hermitian means hermitian-definite in generalized problems */
     92:   if (!ispositive && !eps->isgeneralized && eps->ishermitian) ispositive = PETSC_TRUE;
     93:   if (!eps->isgeneralized) dvd->sB = DVD_MAT_IMPLICIT | DVD_MAT_HERMITIAN | DVD_MAT_IDENTITY | DVD_MAT_UNITARY | DVD_MAT_POS_DEF;
     94:   else dvd->sB = DVD_MAT_IMPLICIT | (eps->ishermitian? DVD_MAT_HERMITIAN: 0) | (ispositive? DVD_MAT_POS_DEF: 0);
     95:   ipB = (dvd->B && data->ipB && DVD_IS(dvd->sB,DVD_MAT_HERMITIAN))?PETSC_TRUE:PETSC_FALSE;
     96:   dvd->sEP = ((!eps->isgeneralized || (eps->isgeneralized && ipB))? DVD_EP_STD: 0) | (ispositive? DVD_EP_HERMITIAN: 0) | ((eps->problem_type == EPS_GHIEP && ipB) ? DVD_EP_INDEFINITE : 0);
     97:   if (data->ipB && !ipB) data->ipB = PETSC_FALSE;
     98:   dvd->correctXnorm = (dvd->B && (DVD_IS(dvd->sB,DVD_MAT_HERMITIAN)||DVD_IS(dvd->sEP,DVD_EP_INDEFINITE)))?PETSC_TRUE:PETSC_FALSE;
     99:   dvd->nev        = eps->nev;
    100:   dvd->which      = eps->which;
    101:   dvd->withTarget = PETSC_TRUE;
    102:   switch (eps->which) {
    103:     case EPS_TARGET_MAGNITUDE:
    104:     case EPS_TARGET_IMAGINARY:
    105:       dvd->target[0] = target = eps->target;
    106:       dvd->target[1] = 1.0;
    107:       break;
    108:     case EPS_TARGET_REAL:
    109:       dvd->target[0] = PetscRealPart(target = eps->target);
    110:       dvd->target[1] = 1.0;
    111:       break;
    112:     case EPS_LARGEST_REAL:
    113:     case EPS_LARGEST_MAGNITUDE:
    114:     case EPS_LARGEST_IMAGINARY: /* TODO: think about this case */
    115:       dvd->target[0] = 1.0;
    116:       dvd->target[1] = target = 0.0;
    117:       break;
    118:     case EPS_SMALLEST_MAGNITUDE:
    119:     case EPS_SMALLEST_REAL:
    120:     case EPS_SMALLEST_IMAGINARY: /* TODO: think about this case */
    121:       dvd->target[0] = target = 0.0;
    122:       dvd->target[1] = 1.0;
    123:       break;
    124:     case EPS_WHICH_USER:
    125:       STGetShift(eps->st,&target);
    126:       dvd->target[0] = target;
    127:       dvd->target[1] = 1.0;
    128:       break;
    129:     case EPS_ALL:
    130:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"This solver does not support computing all eigenvalues");
    131:     default:
    132:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported value of option 'which'");
    133:   }
    134:   dvd->tol = (eps->tol==PETSC_DEFAULT)? SLEPC_DEFAULT_TOL: eps->tol;
    135:   dvd->eps = eps;

    137:   /* Setup the extraction technique */
    138:   if (!eps->extraction) {
    139:     if (ipB || ispositive) eps->extraction = EPS_RITZ;
    140:     else {
    141:       switch (eps->which) {
    142:         case EPS_TARGET_REAL:
    143:         case EPS_TARGET_MAGNITUDE:
    144:         case EPS_TARGET_IMAGINARY:
    145:         case EPS_SMALLEST_MAGNITUDE:
    146:         case EPS_SMALLEST_REAL:
    147:         case EPS_SMALLEST_IMAGINARY:
    148:           eps->extraction = EPS_HARMONIC;
    149:           break;
    150:         case EPS_LARGEST_REAL:
    151:         case EPS_LARGEST_MAGNITUDE:
    152:         case EPS_LARGEST_IMAGINARY:
    153:           eps->extraction = EPS_HARMONIC_LARGEST;
    154:           break;
    155:         default:
    156:           eps->extraction = EPS_RITZ;
    157:       }
    158:     }
    159:   }
    160:   switch (eps->extraction) {
    161:     case EPS_RITZ:              harm = DVD_HARM_NONE; break;
    162:     case EPS_HARMONIC:          harm = DVD_HARM_RR; break;
    163:     case EPS_HARMONIC_RELATIVE: harm = DVD_HARM_RRR; break;
    164:     case EPS_HARMONIC_RIGHT:    harm = DVD_HARM_REIGS; break;
    165:     case EPS_HARMONIC_LARGEST:  harm = DVD_HARM_LEIGS; break;
    166:     default: SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type");
    167:   }

    169:   /* Setup the type of starting subspace */
    170:   init = data->krylovstart? DVD_INITV_KRYLOV: DVD_INITV_CLASSIC;

    172:   /* Preconfigure dvd */
    173:   STGetKSP(eps->st,&ksp);
    174:   dvd_schm_basic_preconf(dvd,&b,eps->mpd,min_size_V,bs,initv,PetscAbs(eps->nini),data->plusk,harm,ksp,init,eps->trackall,data->ipB,data->doubleexp);

    176:   /* Allocate memory */
    177:   EPSAllocateSolution(eps,0);

    179:   /* Setup orthogonalization */
    180:   EPS_SetInnerProduct(eps);
    181:   if (!(ipB && dvd->B)) {
    182:     BVSetMatrix(eps->V,NULL,PETSC_FALSE);
    183:   }

    185:   /* Configure dvd for a basic GD */
    186:   dvd_schm_basic_conf(dvd,&b,eps->mpd,min_size_V,bs,initv,PetscAbs(eps->nini),data->plusk,harm,dvd->withTarget,target,ksp,data->fix,init,eps->trackall,data->ipB,data->dynamic,data->doubleexp);
    187:   return(0);
    188: }

    190: PetscErrorCode EPSSolve_XD(EPS eps)
    191: {
    192:   EPS_DAVIDSON   *data = (EPS_DAVIDSON*)eps->data;
    193:   dvdDashboard   *d = &data->ddb;
    194:   PetscInt       l,k;

    198:   PetscCitationsRegister(citation,&cited);
    199:   /* Call the starting routines */
    200:   EPSDavidsonFLCall(d->startList,d);

    202:   while (eps->reason == EPS_CONVERGED_ITERATING) {

    204:     /* Initialize V, if it is needed */
    205:     BVGetActiveColumns(d->eps->V,&l,&k);
    206:     if (l == k) { d->initV(d); }

    208:     /* Find the best approximated eigenpairs in V, X */
    209:     d->calcPairs(d);

    211:     /* Test for convergence */
    212:     (*eps->stopping)(eps,eps->its,eps->max_it,eps->nconv,eps->nev,&eps->reason,eps->stoppingctx);
    213:     if (eps->reason != EPS_CONVERGED_ITERATING) break;

    215:     /* Expand the subspace */
    216:     d->updateV(d);

    218:     /* Monitor progress */
    219:     eps->nconv = d->nconv;
    220:     eps->its++;
    221:     BVGetActiveColumns(d->eps->V,NULL,&k);
    222:     EPSMonitor(eps,eps->its,eps->nconv+d->npreconv,eps->eigr,eps->eigi,eps->errest,PetscMin(k,eps->nev));
    223:   }

    225:   /* Call the ending routines */
    226:   EPSDavidsonFLCall(d->endList,d);
    227:   return(0);
    228: }

    230: PetscErrorCode EPSReset_XD(EPS eps)
    231: {
    232:   EPS_DAVIDSON   *data = (EPS_DAVIDSON*)eps->data;
    233:   dvdDashboard   *dvd = &data->ddb;

    237:   /* Call step destructors and destroys the list */
    238:   EPSDavidsonFLCall(dvd->destroyList,dvd);
    239:   EPSDavidsonFLDestroy(&dvd->destroyList);
    240:   EPSDavidsonFLDestroy(&dvd->startList);
    241:   EPSDavidsonFLDestroy(&dvd->endList);
    242:   return(0);
    243: }

    245: PetscErrorCode EPSXDSetKrylovStart_XD(EPS eps,PetscBool krylovstart)
    246: {
    247:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

    250:   data->krylovstart = krylovstart;
    251:   return(0);
    252: }

    254: PetscErrorCode EPSXDGetKrylovStart_XD(EPS eps,PetscBool *krylovstart)
    255: {
    256:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

    259:   *krylovstart = data->krylovstart;
    260:   return(0);
    261: }

    263: PetscErrorCode EPSXDSetBlockSize_XD(EPS eps,PetscInt blocksize)
    264: {
    265:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

    268:   if (blocksize == PETSC_DEFAULT || blocksize == PETSC_DECIDE) blocksize = 1;
    269:   if (blocksize <= 0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid blocksize value");
    270:   data->blocksize = blocksize;
    271:   return(0);
    272: }

    274: PetscErrorCode EPSXDGetBlockSize_XD(EPS eps,PetscInt *blocksize)
    275: {
    276:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

    279:   *blocksize = data->blocksize;
    280:   return(0);
    281: }

    283: PetscErrorCode EPSXDSetRestart_XD(EPS eps,PetscInt minv,PetscInt plusk)
    284: {
    285:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

    288:   if (minv == PETSC_DEFAULT || minv == PETSC_DECIDE) minv = 5;
    289:   if (minv <= 0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid minv value");
    290:   if (plusk == PETSC_DEFAULT || plusk == PETSC_DECIDE) plusk = eps->problem_type == EPS_GHIEP?0:1;
    291:   if (plusk < 0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid plusk value");
    292:   data->minv = minv;
    293:   data->plusk = plusk;
    294:   return(0);
    295: }

    297: PetscErrorCode EPSXDGetRestart_XD(EPS eps,PetscInt *minv,PetscInt *plusk)
    298: {
    299:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

    302:   if (minv) *minv = data->minv;
    303:   if (plusk) *plusk = data->plusk;
    304:   return(0);
    305: }

    307: PetscErrorCode EPSXDGetInitialSize_XD(EPS eps,PetscInt *initialsize)
    308: {
    309:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

    312:   *initialsize = data->initialsize;
    313:   return(0);
    314: }

    316: PetscErrorCode EPSXDSetInitialSize_XD(EPS eps,PetscInt initialsize)
    317: {
    318:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

    321:   if (initialsize == PETSC_DEFAULT || initialsize == PETSC_DECIDE) initialsize = 5;
    322:   if (initialsize <= 0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid initial size value");
    323:   data->initialsize = initialsize;
    324:   return(0);
    325: }

    327: PetscErrorCode EPSXDSetBOrth_XD(EPS eps,PetscBool borth)
    328: {
    329:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

    332:   data->ipB = borth;
    333:   return(0);
    334: }

    336: PetscErrorCode EPSXDGetBOrth_XD(EPS eps,PetscBool *borth)
    337: {
    338:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

    341:   *borth = data->ipB;
    342:   return(0);
    343: }

    345: /*
    346:   EPSComputeVectors_XD - Compute eigenvectors from the vectors
    347:   provided by the eigensolver. This version is intended for solvers
    348:   that provide Schur vectors from the QZ decomposition. Given the partial
    349:   Schur decomposition OP*V=V*T, the following steps are performed:
    350:       1) compute eigenvectors of (S,T): S*Z=T*Z*D
    351:       2) compute eigenvectors of OP: X=V*Z
    352:  */
    353: PetscErrorCode EPSComputeVectors_XD(EPS eps)
    354: {
    356:   Mat            X;
    357:   PetscBool      symm;

    360:   PetscObjectTypeCompare((PetscObject)eps->ds,DSHEP,&symm);
    361:   if (symm) return(0);
    362:   DSVectors(eps->ds,DS_MAT_X,NULL,NULL);

    364:   /* V <- V * X */
    365:   DSGetMat(eps->ds,DS_MAT_X,&X);
    366:   BVSetActiveColumns(eps->V,0,eps->nconv);
    367:   BVMultInPlace(eps->V,X,0,eps->nconv);
    368:   MatDestroy(&X);
    369:   return(0);
    370: }