Actual source code: davidson.c

slepc-3.23.1 2025-05-01
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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:    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: {
 37:   EPS_DAVIDSON   *data = (EPS_DAVIDSON*)eps->data;
 38:   dvdDashboard   *dvd = &data->ddb;
 39:   dvdBlackboard  b;
 40:   PetscInt       min_size_V,bs,initv,nmat;
 41:   Mat            A,B;
 42:   KSP            ksp;
 43:   PetscBool      ipB,ispositive;
 44:   HarmType_t     harm;
 45:   InitType_t     init;
 46:   PetscScalar    target;

 48:   PetscFunctionBegin;
 49:   EPSCheckNotStructured(eps);
 50:   /* Setup EPS options and get the problem specification */
 51:   if (eps->nev==0) eps->nev = 1;
 52:   bs = data->blocksize;
 53:   if (bs <= 0) bs = 1;
 54:   if (eps->ncv!=PETSC_DETERMINE) {
 55:     PetscCheck(eps->ncv>=eps->nev,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The value of ncv must be at least nev");
 56:   } else if (eps->mpd!=PETSC_DETERMINE) eps->ncv = eps->mpd + eps->nev + bs;
 57:   else if (eps->n < 10) eps->ncv = eps->n+eps->nev+bs;
 58:   else if (eps->nev < 500) eps->ncv = PetscMax(eps->nev,PetscMin(eps->n-bs,PetscMax(2*eps->nev,eps->nev+15))+bs);
 59:   else eps->ncv = PetscMax(eps->nev,PetscMin(eps->n-bs,eps->nev+500)+bs);
 60:   if (eps->mpd==PETSC_DETERMINE) eps->mpd = PetscMin(eps->n,eps->ncv);
 61:   PetscCheck(eps->mpd<=eps->ncv,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The mpd parameter has to be less than or equal to ncv");
 62:   PetscCheck(eps->mpd>=2,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The mpd parameter has to be greater than 2");
 63:   if (eps->max_it == PETSC_DETERMINE) eps->max_it = PetscMax(100*eps->ncv,2*eps->n);
 64:   if (!eps->which) eps->which = EPS_LARGEST_MAGNITUDE;
 65:   PetscCheck(eps->nev+bs<=eps->ncv,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The value of ncv has to be greater than nev plus blocksize");
 66:   PetscCheck(!eps->trueres,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"-eps_true_residual is disabled in this solver.");
 67:   EPSCheckUnsupported(eps,EPS_FEATURE_REGION | EPS_FEATURE_TWOSIDED | EPS_FEATURE_THRESHOLD);

 69:   if (!data->minv) data->minv = (eps->n && eps->n<10)? 1: PetscMin(PetscMax(bs,6),eps->mpd/2);
 70:   min_size_V = data->minv;
 71:   PetscCheck(min_size_V+bs<=eps->mpd,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The value of minv must be less than mpd minus blocksize");
 72:   if (data->plusk == PETSC_DETERMINE) {
 73:     if (eps->problem_type == EPS_GHIEP || eps->nev+bs>eps->ncv) data->plusk = 0;
 74:     else data->plusk = 1;
 75:   }
 76:   if (!data->initialsize) data->initialsize = (eps->n && eps->n<10)? 1: 6;
 77:   initv = data->initialsize;
 78:   PetscCheck(eps->mpd>=initv,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The initv parameter has to be less than or equal to mpd");

 80:   /* Change the default sigma to inf if necessary */
 81:   if (eps->which == EPS_LARGEST_MAGNITUDE || eps->which == EPS_LARGEST_REAL || eps->which == EPS_LARGEST_IMAGINARY) PetscCall(STSetDefaultShift(eps->st,PETSC_MAX_REAL));

 83:   /* Set up preconditioner */
 84:   PetscCall(STSetUp(eps->st));

 86:   /* Setup problem specification in dvd */
 87:   PetscCall(STGetNumMatrices(eps->st,&nmat));
 88:   PetscCall(STGetMatrix(eps->st,0,&A));
 89:   if (nmat>1) PetscCall(STGetMatrix(eps->st,1,&B));
 90:   PetscCall(EPSReset_XD(eps));
 91:   PetscCall(PetscMemzero(dvd,sizeof(dvdDashboard)));
 92:   dvd->A = A; dvd->B = eps->isgeneralized? B: NULL;
 93:   ispositive = eps->ispositive;
 94:   dvd->sA = DVD_MAT_IMPLICIT | (eps->ishermitian? DVD_MAT_HERMITIAN: 0) | ((ispositive && !eps->isgeneralized) ? DVD_MAT_POS_DEF: 0);
 95:   /* Assume -eps_hermitian means hermitian-definite in generalized problems */
 96:   if (!ispositive && !eps->isgeneralized && eps->ishermitian) ispositive = PETSC_TRUE;
 97:   if (!eps->isgeneralized) dvd->sB = DVD_MAT_IMPLICIT | DVD_MAT_HERMITIAN | DVD_MAT_IDENTITY | DVD_MAT_UNITARY | DVD_MAT_POS_DEF;
 98:   else dvd->sB = DVD_MAT_IMPLICIT | (eps->ishermitian? DVD_MAT_HERMITIAN: 0) | (ispositive? DVD_MAT_POS_DEF: 0);
 99:   ipB = (dvd->B && data->ipB && DVD_IS(dvd->sB,DVD_MAT_HERMITIAN))?PETSC_TRUE:PETSC_FALSE;
100:   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);
101:   if (data->ipB && !ipB) data->ipB = PETSC_FALSE;
102:   dvd->correctXnorm = (dvd->B && (DVD_IS(dvd->sB,DVD_MAT_HERMITIAN)||DVD_IS(dvd->sEP,DVD_EP_INDEFINITE)))?PETSC_TRUE:PETSC_FALSE;
103:   dvd->nev        = eps->nev;
104:   dvd->which      = eps->which;
105:   dvd->withTarget = PETSC_TRUE;
106:   switch (eps->which) {
107:     case EPS_TARGET_MAGNITUDE:
108:     case EPS_TARGET_IMAGINARY:
109:       dvd->target[0] = target = eps->target;
110:       dvd->target[1] = 1.0;
111:       break;
112:     case EPS_TARGET_REAL:
113:       dvd->target[0] = PetscRealPart(target = eps->target);
114:       dvd->target[1] = 1.0;
115:       break;
116:     case EPS_LARGEST_REAL:
117:     case EPS_LARGEST_MAGNITUDE:
118:     case EPS_LARGEST_IMAGINARY: /* TODO: think about this case */
119:       dvd->target[0] = 1.0;
120:       dvd->target[1] = target = 0.0;
121:       break;
122:     case EPS_SMALLEST_MAGNITUDE:
123:     case EPS_SMALLEST_REAL:
124:     case EPS_SMALLEST_IMAGINARY: /* TODO: think about this case */
125:       dvd->target[0] = target = 0.0;
126:       dvd->target[1] = 1.0;
127:       break;
128:     case EPS_WHICH_USER:
129:       PetscCall(STGetShift(eps->st,&target));
130:       dvd->target[0] = target;
131:       dvd->target[1] = 1.0;
132:       break;
133:     case EPS_ALL:
134:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"This solver does not support computing all eigenvalues");
135:     default:
136:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported value of option 'which'");
137:   }
138:   dvd->tol = SlepcDefaultTol(eps->tol);
139:   dvd->eps = eps;

141:   /* Setup the extraction technique */
142:   if (!eps->extraction) {
143:     if (ipB || ispositive) eps->extraction = EPS_RITZ;
144:     else {
145:       switch (eps->which) {
146:         case EPS_TARGET_REAL:
147:         case EPS_TARGET_MAGNITUDE:
148:         case EPS_TARGET_IMAGINARY:
149:         case EPS_SMALLEST_MAGNITUDE:
150:         case EPS_SMALLEST_REAL:
151:         case EPS_SMALLEST_IMAGINARY:
152:           eps->extraction = EPS_HARMONIC;
153:           break;
154:         case EPS_LARGEST_REAL:
155:         case EPS_LARGEST_MAGNITUDE:
156:         case EPS_LARGEST_IMAGINARY:
157:           eps->extraction = EPS_HARMONIC_LARGEST;
158:           break;
159:         default:
160:           eps->extraction = EPS_RITZ;
161:       }
162:     }
163:   }
164:   switch (eps->extraction) {
165:     case EPS_RITZ:              harm = DVD_HARM_NONE; break;
166:     case EPS_HARMONIC:          harm = DVD_HARM_RR; break;
167:     case EPS_HARMONIC_RELATIVE: harm = DVD_HARM_RRR; break;
168:     case EPS_HARMONIC_RIGHT:    harm = DVD_HARM_REIGS; break;
169:     case EPS_HARMONIC_LARGEST:  harm = DVD_HARM_LEIGS; break;
170:     default: SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type");
171:   }

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

176:   /* Preconfigure dvd */
177:   PetscCall(STGetKSP(eps->st,&ksp));
178:   PetscCall(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));

180:   /* Allocate memory */
181:   PetscCall(EPSAllocateSolution(eps,0));

183:   /* Setup orthogonalization */
184:   PetscCall(EPS_SetInnerProduct(eps));
185:   if (!(ipB && dvd->B)) PetscCall(BVSetMatrix(eps->V,NULL,PETSC_FALSE));

187:   /* Configure dvd for a basic GD */
188:   PetscCall(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));
189:   PetscFunctionReturn(PETSC_SUCCESS);
190: }

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

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

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

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

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

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

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

219:     /* Monitor progress */
220:     eps->nconv = d->nconv;
221:     eps->its++;
222:     PetscCall(BVGetActiveColumns(d->eps->V,NULL,&k));
223:     PetscCall(EPSMonitor(eps,eps->its,eps->nconv+d->npreconv,eps->eigr,eps->eigi,eps->errest,PetscMin(k,eps->nev)));
224:   }

226:   /* Call the ending routines */
227:   PetscCall(EPSDavidsonFLCall(d->endList,d));
228:   PetscFunctionReturn(PETSC_SUCCESS);
229: }

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

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

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

249:   PetscFunctionBegin;
250:   data->krylovstart = krylovstart;
251:   PetscFunctionReturn(PETSC_SUCCESS);
252: }

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

258:   PetscFunctionBegin;
259:   *krylovstart = data->krylovstart;
260:   PetscFunctionReturn(PETSC_SUCCESS);
261: }

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

267:   PetscFunctionBegin;
268:   if (blocksize == PETSC_DEFAULT || blocksize == PETSC_DECIDE) blocksize = 1;
269:   PetscCheck(blocksize>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid blocksize value, must be >0");
270:   if (data->blocksize != blocksize) {
271:     data->blocksize = blocksize;
272:     eps->state      = EPS_STATE_INITIAL;
273:   }
274:   PetscFunctionReturn(PETSC_SUCCESS);
275: }

277: PetscErrorCode EPSXDGetBlockSize_XD(EPS eps,PetscInt *blocksize)
278: {
279:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

281:   PetscFunctionBegin;
282:   *blocksize = data->blocksize;
283:   PetscFunctionReturn(PETSC_SUCCESS);
284: }

286: PetscErrorCode EPSXDSetRestart_XD(EPS eps,PetscInt minv,PetscInt plusk)
287: {
288:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

290:   PetscFunctionBegin;
291:   if (minv == PETSC_DETERMINE) {
292:     if (data->minv != 0) eps->state = EPS_STATE_INITIAL;
293:     data->minv = 0;
294:   } else if (minv != PETSC_CURRENT) {
295:     PetscCheck(minv>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid minv value, must be >0");
296:     if (data->minv != minv) eps->state = EPS_STATE_INITIAL;
297:     data->minv = minv;
298:   }
299:   if (plusk == PETSC_DETERMINE) {
300:     if (data->plusk != PETSC_DETERMINE) eps->state = EPS_STATE_INITIAL;
301:     data->plusk = PETSC_DETERMINE;
302:   } else if (plusk != PETSC_CURRENT) {
303:     PetscCheck(plusk>=0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid plusk value, must be >0");
304:     if (data->plusk != plusk) eps->state = EPS_STATE_INITIAL;
305:     data->plusk = plusk;
306:   }
307:   PetscFunctionReturn(PETSC_SUCCESS);
308: }

310: PetscErrorCode EPSXDGetRestart_XD(EPS eps,PetscInt *minv,PetscInt *plusk)
311: {
312:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

314:   PetscFunctionBegin;
315:   if (minv) *minv = data->minv;
316:   if (plusk) *plusk = data->plusk;
317:   PetscFunctionReturn(PETSC_SUCCESS);
318: }

320: PetscErrorCode EPSXDGetInitialSize_XD(EPS eps,PetscInt *initialsize)
321: {
322:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

324:   PetscFunctionBegin;
325:   *initialsize = data->initialsize;
326:   PetscFunctionReturn(PETSC_SUCCESS);
327: }

329: PetscErrorCode EPSXDSetInitialSize_XD(EPS eps,PetscInt initialsize)
330: {
331:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

333:   PetscFunctionBegin;
334:   if (initialsize == PETSC_DEFAULT || initialsize == PETSC_DECIDE) initialsize = 0;
335:   else PetscCheck(initialsize>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid initial size value, must be >0");
336:   if (data->initialsize != initialsize) {
337:     data->initialsize = initialsize;
338:     eps->state        = EPS_STATE_INITIAL;
339:   }
340:   PetscFunctionReturn(PETSC_SUCCESS);
341: }

343: PetscErrorCode EPSXDSetBOrth_XD(EPS eps,PetscBool borth)
344: {
345:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

347:   PetscFunctionBegin;
348:   data->ipB = borth;
349:   PetscFunctionReturn(PETSC_SUCCESS);
350: }

352: PetscErrorCode EPSXDGetBOrth_XD(EPS eps,PetscBool *borth)
353: {
354:   EPS_DAVIDSON *data = (EPS_DAVIDSON*)eps->data;

356:   PetscFunctionBegin;
357:   *borth = data->ipB;
358:   PetscFunctionReturn(PETSC_SUCCESS);
359: }

361: /*
362:   EPSComputeVectors_XD - Compute eigenvectors from the vectors
363:   provided by the eigensolver. This version is intended for solvers
364:   that provide Schur vectors from the QZ decomposition. Given the partial
365:   Schur decomposition OP*V=V*T, the following steps are performed:
366:       1) compute eigenvectors of (S,T): S*Z=T*Z*D
367:       2) compute eigenvectors of OP: X=V*Z
368:  */
369: PetscErrorCode EPSComputeVectors_XD(EPS eps)
370: {
371:   Mat            X;
372:   PetscBool      symm;

374:   PetscFunctionBegin;
375:   PetscCall(PetscObjectTypeCompare((PetscObject)eps->ds,DSHEP,&symm));
376:   if (symm) PetscFunctionReturn(PETSC_SUCCESS);
377:   PetscCall(DSVectors(eps->ds,DS_MAT_X,NULL,NULL));

379:   /* V <- V * X */
380:   PetscCall(DSGetMat(eps->ds,DS_MAT_X,&X));
381:   PetscCall(BVSetActiveColumns(eps->V,0,eps->nconv));
382:   PetscCall(BVMultInPlace(eps->V,X,0,eps->nconv));
383:   PetscCall(DSRestoreMat(eps->ds,DS_MAT_X,&X));
384:   PetscFunctionReturn(PETSC_SUCCESS);
385: }