Actual source code: lobpcg.c

slepc-main 2024-12-17
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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:    SLEPc eigensolver: "lobpcg"

 13:    Method: Locally Optimal Block Preconditioned Conjugate Gradient

 15:    Algorithm:

 17:        LOBPCG with soft and hard locking. Follows the implementation
 18:        in BLOPEX [2].

 20:    References:

 22:        [1] A. V. Knyazev, "Toward the optimal preconditioned eigensolver:
 23:            locally optimal block preconditioned conjugate gradient method",
 24:            SIAM J. Sci. Comput. 23(2):517-541, 2001.

 26:        [2] A. V. Knyazev et al., "Block Locally Optimal Preconditioned
 27:            Eigenvalue Xolvers (BLOPEX) in Hypre and PETSc", SIAM J. Sci.
 28:            Comput. 29(5):2224-2239, 2007.
 29: */

 31: #include <slepc/private/epsimpl.h>

 33: typedef struct {
 34:   PetscInt  bs;        /* block size */
 35:   PetscBool lock;      /* soft locking active/inactive */
 36:   PetscReal restart;   /* restart parameter */
 37:   PetscInt  guard;     /* number of guard vectors */
 38: } EPS_LOBPCG;

 40: static PetscErrorCode EPSSetDimensions_LOBPCG(EPS eps,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
 41: {
 42:   EPS_LOBPCG *ctx = (EPS_LOBPCG*)eps->data;
 43:   PetscInt   k;

 45:   PetscFunctionBegin;
 46:   if (*nev==0) *nev = 1;
 47:   k = PetscMax(3*ctx->bs,((*nev-1)/ctx->bs+3)*ctx->bs);
 48:   if (*ncv!=PETSC_DETERMINE) { /* ncv set */
 49:     PetscCheck(*ncv>=k,PetscObjectComm((PetscObject)eps),PETSC_ERR_USER_INPUT,"The value of ncv is not sufficiently large");
 50:   } else *ncv = k;
 51:   if (*mpd==PETSC_DETERMINE) *mpd = 3*ctx->bs;
 52:   else PetscCheck(*mpd==3*ctx->bs,PetscObjectComm((PetscObject)eps),PETSC_ERR_USER_INPUT,"This solver does not allow a value of mpd different from 3*blocksize");
 53:   PetscFunctionReturn(PETSC_SUCCESS);
 54: }

 56: static PetscErrorCode EPSSetUp_LOBPCG(EPS eps)
 57: {
 58:   EPS_LOBPCG     *ctx = (EPS_LOBPCG*)eps->data;

 60:   PetscFunctionBegin;
 61:   EPSCheckHermitianDefinite(eps);
 62:   EPSCheckNotStructured(eps);
 63:   if (!ctx->bs) ctx->bs = PetscMin(16,eps->nev?eps->nev:1);
 64:   PetscCheck(eps->n-eps->nds>=5*ctx->bs,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"The problem size is too small relative to the block size");
 65:   PetscCall(EPSSetDimensions_LOBPCG(eps,&eps->nev,&eps->ncv,&eps->mpd));
 66:   if (eps->max_it==PETSC_DETERMINE) eps->max_it = PetscMax(100,2*eps->n/eps->ncv);
 67:   if (!eps->which) eps->which = EPS_SMALLEST_REAL;
 68:   PetscCheck(eps->which==EPS_SMALLEST_REAL || eps->which==EPS_LARGEST_REAL,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"This solver supports only smallest real or largest real eigenvalues");
 69:   EPSCheckUnsupported(eps,EPS_FEATURE_ARBITRARY | EPS_FEATURE_REGION | EPS_FEATURE_EXTRACTION | EPS_FEATURE_THRESHOLD);
 70:   EPSCheckIgnored(eps,EPS_FEATURE_BALANCE);

 72:   if (!ctx->restart) ctx->restart = 0.9;

 74:   /* number of guard vectors */
 75:   if (ctx->bs==1) ctx->guard = 0;
 76:   else ctx->guard = PetscMin((PetscInt)((1.0-ctx->restart)*ctx->bs+0.45),ctx->bs-1);

 78:   PetscCall(EPSAllocateSolution(eps,0));
 79:   PetscCall(EPS_SetInnerProduct(eps));
 80:   PetscCall(DSSetType(eps->ds,DSGHEP));
 81:   PetscCall(DSAllocate(eps->ds,eps->mpd));
 82:   PetscCall(EPSSetWorkVecs(eps,1));
 83:   PetscFunctionReturn(PETSC_SUCCESS);
 84: }

 86: static PetscErrorCode EPSSolve_LOBPCG(EPS eps)
 87: {
 88:   EPS_LOBPCG     *ctx = (EPS_LOBPCG*)eps->data;
 89:   PetscInt       i,j,k,nv,ini,nmat,nc,nconv,locked,its,prev=0;
 90:   PetscReal      norm;
 91:   PetscScalar    *eigr,dot;
 92:   PetscBool      breakdown,countc,flip=PETSC_FALSE,checkprecond=PETSC_FALSE;
 93:   Mat            A,B,M,V=NULL,W=NULL;
 94:   Vec            v,z,w=eps->work[0];
 95:   BV             X,Y=NULL,Z,R,P,AX,BX;
 96:   SlepcSC        sc;

 98:   PetscFunctionBegin;
 99:   PetscCall(STGetNumMatrices(eps->st,&nmat));
100:   PetscCall(STGetMatrix(eps->st,0,&A));
101:   if (nmat>1) PetscCall(STGetMatrix(eps->st,1,&B));
102:   else B = NULL;

104:   if (eps->which==EPS_LARGEST_REAL) {  /* flip spectrum */
105:     flip = PETSC_TRUE;
106:     PetscCall(DSGetSlepcSC(eps->ds,&sc));
107:     sc->comparison = SlepcCompareSmallestReal;
108:   }

110:   /* undocumented option to check for a positive-definite preconditioner (turn-off by default) */
111:   PetscCall(PetscOptionsGetBool(NULL,NULL,"-eps_lobpcg_checkprecond",&checkprecond,NULL));

113:   /* 1. Allocate memory */
114:   PetscCall(PetscCalloc1(3*ctx->bs,&eigr));
115:   PetscCall(BVDuplicateResize(eps->V,3*ctx->bs,&Z));
116:   PetscCall(BVDuplicateResize(eps->V,ctx->bs,&X));
117:   PetscCall(BVDuplicateResize(eps->V,ctx->bs,&R));
118:   PetscCall(BVDuplicateResize(eps->V,ctx->bs,&P));
119:   PetscCall(BVDuplicateResize(eps->V,ctx->bs,&AX));
120:   if (B) PetscCall(BVDuplicateResize(eps->V,ctx->bs,&BX));
121:   nc = eps->nds;
122:   if (nc>0 || eps->nev>ctx->bs-ctx->guard) PetscCall(BVDuplicateResize(eps->V,nc+eps->nev,&Y));
123:   if (nc>0) {
124:     for (j=0;j<nc;j++) {
125:       PetscCall(BVGetColumn(eps->V,-nc+j,&v));
126:       PetscCall(BVInsertVec(Y,j,v));
127:       PetscCall(BVRestoreColumn(eps->V,-nc+j,&v));
128:     }
129:     PetscCall(BVSetActiveColumns(Y,0,nc));
130:   }

132:   /* 2. Apply the constraints to the initial vectors */
133:   /* 3. B-orthogonalize initial vectors */
134:   for (k=eps->nini;k<eps->ncv-ctx->bs;k++) { /* Generate more initial vectors if necessary */
135:     PetscCall(BVSetRandomColumn(eps->V,k));
136:     PetscCall(BVOrthonormalizeColumn(eps->V,k,PETSC_TRUE,NULL,NULL));
137:   }
138:   nv = ctx->bs;
139:   PetscCall(BVSetActiveColumns(eps->V,0,nv));
140:   PetscCall(BVSetActiveColumns(Z,0,nv));
141:   PetscCall(BVCopy(eps->V,Z));
142:   PetscCall(BVCopy(Z,X));

144:   /* 4. Compute initial Ritz vectors */
145:   PetscCall(BVMatMult(X,A,AX));
146:   PetscCall(DSSetDimensions(eps->ds,nv,0,0));
147:   PetscCall(DSGetMat(eps->ds,DS_MAT_A,&M));
148:   PetscCall(BVMatProject(AX,NULL,X,M));
149:   if (flip) PetscCall(MatScale(M,-1.0));
150:   PetscCall(DSRestoreMat(eps->ds,DS_MAT_A,&M));
151:   PetscCall(DSSetIdentity(eps->ds,DS_MAT_B));
152:   PetscCall(DSSetState(eps->ds,DS_STATE_RAW));
153:   PetscCall(DSSolve(eps->ds,eigr,NULL));
154:   PetscCall(DSSort(eps->ds,eigr,NULL,NULL,NULL,NULL));
155:   PetscCall(DSSynchronize(eps->ds,eigr,NULL));
156:   for (j=0;j<nv;j++) eps->eigr[j] = flip? -eigr[j]: eigr[j];
157:   PetscCall(DSVectors(eps->ds,DS_MAT_X,NULL,NULL));
158:   PetscCall(DSGetMat(eps->ds,DS_MAT_X,&M));
159:   PetscCall(BVMultInPlace(X,M,0,nv));
160:   PetscCall(BVMultInPlace(AX,M,0,nv));
161:   PetscCall(DSRestoreMat(eps->ds,DS_MAT_X,&M));

163:   /* 5. Initialize range of active iterates */
164:   locked = 0;  /* hard-locked vectors, the leading locked columns of V are eigenvectors */
165:   nconv  = 0;  /* number of converged eigenvalues in the current block */
166:   its    = 0;  /* iterations for the current block */

168:   /* 6. Main loop */
169:   while (eps->reason == EPS_CONVERGED_ITERATING) {

171:     if (ctx->lock) {
172:       PetscCall(BVSetActiveColumns(R,nconv,ctx->bs));
173:       PetscCall(BVSetActiveColumns(AX,nconv,ctx->bs));
174:       if (B) PetscCall(BVSetActiveColumns(BX,nconv,ctx->bs));
175:     }

177:     /* 7. Compute residuals */
178:     ini = (ctx->lock)? nconv: 0;
179:     PetscCall(BVCopy(AX,R));
180:     if (B) PetscCall(BVMatMult(X,B,BX));
181:     for (j=ini;j<ctx->bs;j++) {
182:       PetscCall(BVGetColumn(R,j,&v));
183:       PetscCall(BVGetColumn(B?BX:X,j,&z));
184:       PetscCall(VecAXPY(v,-eps->eigr[locked+j],z));
185:       PetscCall(BVRestoreColumn(R,j,&v));
186:       PetscCall(BVRestoreColumn(B?BX:X,j,&z));
187:     }

189:     /* 8. Compute residual norms and update index set of active iterates */
190:     k = ini;
191:     countc = PETSC_TRUE;
192:     for (j=ini;j<ctx->bs;j++) {
193:       i = locked+j;
194:       PetscCall(BVGetColumn(R,j,&v));
195:       PetscCall(VecNorm(v,NORM_2,&norm));
196:       PetscCall(BVRestoreColumn(R,j,&v));
197:       PetscCall((*eps->converged)(eps,eps->eigr[i],eps->eigi[i],norm,&eps->errest[i],eps->convergedctx));
198:       if (countc) {
199:         if (eps->errest[i] < eps->tol) k++;
200:         else countc = PETSC_FALSE;
201:       }
202:       if (!countc && !eps->trackall) break;
203:     }
204:     nconv = k;
205:     eps->nconv = locked + nconv;
206:     if (its) PetscCall(EPSMonitor(eps,eps->its+its,eps->nconv,eps->eigr,eps->eigi,eps->errest,locked+ctx->bs));
207:     PetscCall((*eps->stopping)(eps,eps->its+its,eps->max_it,eps->nconv,eps->nev,&eps->reason,eps->stoppingctx));
208:     if (eps->reason != EPS_CONVERGED_ITERATING || nconv >= ctx->bs-ctx->guard) {
209:       PetscCall(BVSetActiveColumns(eps->V,locked,eps->nconv));
210:       PetscCall(BVSetActiveColumns(X,0,nconv));
211:       PetscCall(BVCopy(X,eps->V));
212:     }
213:     if (eps->reason != EPS_CONVERGED_ITERATING) {
214:       break;
215:     } else if (nconv >= ctx->bs-ctx->guard) {
216:       eps->its += its-1;
217:       its = 0;
218:     } else its++;

220:     if (nconv >= ctx->bs-ctx->guard) {  /* force hard locking of vectors and compute new R */

222:       /* extend constraints */
223:       PetscCall(BVSetActiveColumns(Y,nc+locked,nc+locked+nconv));
224:       PetscCall(BVCopy(X,Y));
225:       PetscCall(BVSetActiveColumns(Y,0,nc+locked+nconv));

227:       /* shift work BV's */
228:       for (j=nconv;j<ctx->bs;j++) {
229:         PetscCall(BVCopyColumn(X,j,j-nconv));
230:         PetscCall(BVCopyColumn(R,j,j-nconv));
231:         PetscCall(BVCopyColumn(P,j,j-nconv));
232:         PetscCall(BVCopyColumn(AX,j,j-nconv));
233:         if (B) PetscCall(BVCopyColumn(BX,j,j-nconv));
234:       }

236:       /* set new initial vectors */
237:       PetscCall(BVSetActiveColumns(eps->V,locked+ctx->bs,locked+ctx->bs+nconv));
238:       PetscCall(BVSetActiveColumns(X,ctx->bs-nconv,ctx->bs));
239:       PetscCall(BVCopy(eps->V,X));
240:       for (j=ctx->bs-nconv;j<ctx->bs;j++) {
241:         PetscCall(BVGetColumn(X,j,&v));
242:         PetscCall(BVOrthogonalizeVec(Y,v,NULL,&norm,&breakdown));
243:         if (norm>0.0 && !breakdown) PetscCall(VecScale(v,1.0/norm));
244:         else {
245:           PetscCall(PetscInfo(eps,"Orthogonalization of initial vector failed\n"));
246:           eps->reason = EPS_DIVERGED_BREAKDOWN;
247:           goto diverged;
248:         }
249:         PetscCall(BVRestoreColumn(X,j,&v));
250:       }
251:       locked += nconv;
252:       nconv = 0;
253:       PetscCall(BVSetActiveColumns(X,nconv,ctx->bs));

255:       /* B-orthogonalize initial vectors */
256:       PetscCall(BVOrthogonalize(X,NULL));
257:       PetscCall(BVSetActiveColumns(Z,nconv,ctx->bs));
258:       PetscCall(BVSetActiveColumns(AX,nconv,ctx->bs));
259:       PetscCall(BVCopy(X,Z));

261:       /* compute initial Ritz vectors */
262:       nv = ctx->bs;
263:       PetscCall(BVMatMult(X,A,AX));
264:       PetscCall(DSSetDimensions(eps->ds,nv,0,0));
265:       PetscCall(DSGetMat(eps->ds,DS_MAT_A,&M));
266:       PetscCall(BVMatProject(AX,NULL,X,M));
267:       if (flip) PetscCall(MatScale(M,-1.0));
268:       PetscCall(DSRestoreMat(eps->ds,DS_MAT_A,&M));
269:       PetscCall(DSSetIdentity(eps->ds,DS_MAT_B));
270:       PetscCall(DSSetState(eps->ds,DS_STATE_RAW));
271:       PetscCall(DSSolve(eps->ds,eigr,NULL));
272:       PetscCall(DSSort(eps->ds,eigr,NULL,NULL,NULL,NULL));
273:       PetscCall(DSSynchronize(eps->ds,eigr,NULL));
274:       for (j=0;j<nv;j++) if (locked+j<eps->ncv) eps->eigr[locked+j] = flip? -eigr[j]: eigr[j];
275:       PetscCall(DSVectors(eps->ds,DS_MAT_X,NULL,NULL));
276:       PetscCall(DSGetMat(eps->ds,DS_MAT_X,&M));
277:       PetscCall(BVMultInPlace(X,M,0,nv));
278:       PetscCall(BVMultInPlace(AX,M,0,nv));
279:       PetscCall(DSRestoreMat(eps->ds,DS_MAT_X,&M));

281:       continue;   /* skip the rest of the iteration */
282:     }

284:     ini = (ctx->lock)? nconv: 0;
285:     if (ctx->lock) {
286:       PetscCall(BVSetActiveColumns(R,nconv,ctx->bs));
287:       PetscCall(BVSetActiveColumns(P,nconv,ctx->bs));
288:       PetscCall(BVSetActiveColumns(AX,nconv,ctx->bs));
289:       if (B) PetscCall(BVSetActiveColumns(BX,nconv,ctx->bs));
290:     }

292:     /* 9. Apply preconditioner to the residuals */
293:     PetscCall(BVGetMat(R,&V));
294:     if (prev != ctx->bs-ini) {
295:       prev = ctx->bs-ini;
296:       PetscCall(MatDestroy(&W));
297:       PetscCall(MatDuplicate(V,MAT_SHARE_NONZERO_PATTERN,&W));
298:     }
299:     PetscCall(STApplyMat(eps->st,V,W));
300:     if (checkprecond) {
301:       for (j=ini;j<ctx->bs;j++) {
302:         PetscCall(MatDenseGetColumnVecRead(V,j-ini,&v));
303:         PetscCall(MatDenseGetColumnVecRead(W,j-ini,&w));
304:         PetscCall(VecDot(v,w,&dot));
305:         PetscCall(MatDenseRestoreColumnVecRead(W,j-ini,&w));
306:         PetscCall(MatDenseRestoreColumnVecRead(V,j-ini,&v));
307:         if (PetscRealPart(dot)<0.0) {
308:           PetscCall(PetscInfo(eps,"The preconditioner is not positive-definite\n"));
309:           eps->reason = EPS_DIVERGED_BREAKDOWN;
310:           goto diverged;
311:         }
312:       }
313:     }
314:     if (nc+locked>0) {
315:       for (j=ini;j<ctx->bs;j++) {
316:         PetscCall(MatDenseGetColumnVecWrite(W,j-ini,&w));
317:         PetscCall(BVOrthogonalizeVec(Y,w,NULL,&norm,&breakdown));
318:         if (norm>0.0 && !breakdown) PetscCall(VecScale(w,1.0/norm));
319:         PetscCall(MatDenseRestoreColumnVecWrite(W,j-ini,&w));
320:         if (norm<=0.0 || breakdown) {
321:           PetscCall(PetscInfo(eps,"Orthogonalization of preconditioned residual failed\n"));
322:           eps->reason = EPS_DIVERGED_BREAKDOWN;
323:           goto diverged;
324:         }
325:       }
326:     }
327:     PetscCall(MatCopy(W,V,SAME_NONZERO_PATTERN));
328:     PetscCall(BVRestoreMat(R,&V));

330:     /* 11. B-orthonormalize preconditioned residuals */
331:     PetscCall(BVOrthogonalize(R,NULL));

333:     /* 13-16. B-orthonormalize conjugate directions */
334:     if (its>1) PetscCall(BVOrthogonalize(P,NULL));

336:     /* 17-23. Compute symmetric Gram matrices */
337:     PetscCall(BVSetActiveColumns(Z,0,ctx->bs));
338:     PetscCall(BVSetActiveColumns(X,0,ctx->bs));
339:     PetscCall(BVCopy(X,Z));
340:     PetscCall(BVSetActiveColumns(Z,ctx->bs,2*ctx->bs-ini));
341:     PetscCall(BVCopy(R,Z));
342:     if (its>1) {
343:       PetscCall(BVSetActiveColumns(Z,2*ctx->bs-ini,3*ctx->bs-2*ini));
344:       PetscCall(BVCopy(P,Z));
345:     }

347:     if (its>1) nv = 3*ctx->bs-2*ini;
348:     else nv = 2*ctx->bs-ini;

350:     PetscCall(BVSetActiveColumns(Z,0,nv));
351:     PetscCall(DSSetDimensions(eps->ds,nv,0,0));
352:     PetscCall(DSGetMat(eps->ds,DS_MAT_A,&M));
353:     PetscCall(BVMatProject(Z,A,Z,M));
354:     if (flip) PetscCall(MatScale(M,-1.0));
355:     PetscCall(DSRestoreMat(eps->ds,DS_MAT_A,&M));
356:     PetscCall(DSGetMat(eps->ds,DS_MAT_B,&M));
357:     PetscCall(BVMatProject(Z,B,Z,M)); /* covers also the case B=NULL */
358:     PetscCall(DSRestoreMat(eps->ds,DS_MAT_B,&M));

360:     /* 24. Solve the generalized eigenvalue problem */
361:     PetscCall(DSSetState(eps->ds,DS_STATE_RAW));
362:     PetscCall(DSSolve(eps->ds,eigr,NULL));
363:     PetscCall(DSSort(eps->ds,eigr,NULL,NULL,NULL,NULL));
364:     PetscCall(DSSynchronize(eps->ds,eigr,NULL));
365:     for (j=0;j<nv;j++) if (locked+j<eps->ncv) eps->eigr[locked+j] = flip? -eigr[j]: eigr[j];
366:     PetscCall(DSVectors(eps->ds,DS_MAT_X,NULL,NULL));

368:     /* 25-33. Compute Ritz vectors */
369:     PetscCall(DSGetMat(eps->ds,DS_MAT_X,&M));
370:     PetscCall(BVSetActiveColumns(Z,ctx->bs,nv));
371:     if (ctx->lock) PetscCall(BVSetActiveColumns(P,0,ctx->bs));
372:     PetscCall(BVMult(P,1.0,0.0,Z,M));
373:     PetscCall(BVCopy(P,X));
374:     if (ctx->lock) PetscCall(BVSetActiveColumns(P,nconv,ctx->bs));
375:     PetscCall(BVSetActiveColumns(Z,0,ctx->bs));
376:     PetscCall(BVMult(X,1.0,1.0,Z,M));
377:     if (ctx->lock) PetscCall(BVSetActiveColumns(X,nconv,ctx->bs));
378:     PetscCall(BVMatMult(X,A,AX));
379:     PetscCall(DSRestoreMat(eps->ds,DS_MAT_X,&M));
380:   }

382: diverged:
383:   eps->its += its;

385:   if (flip) sc->comparison = SlepcCompareLargestReal;
386:   PetscCall(PetscFree(eigr));
387:   PetscCall(MatDestroy(&W));
388:   if (V) PetscCall(BVRestoreMat(R,&V)); /* only needed when goto diverged is reached */
389:   PetscCall(BVDestroy(&Z));
390:   PetscCall(BVDestroy(&X));
391:   PetscCall(BVDestroy(&R));
392:   PetscCall(BVDestroy(&P));
393:   PetscCall(BVDestroy(&AX));
394:   if (B) PetscCall(BVDestroy(&BX));
395:   if (nc>0 || eps->nev>ctx->bs-ctx->guard) PetscCall(BVDestroy(&Y));
396:   PetscFunctionReturn(PETSC_SUCCESS);
397: }

399: static PetscErrorCode EPSLOBPCGSetBlockSize_LOBPCG(EPS eps,PetscInt bs)
400: {
401:   EPS_LOBPCG *ctx = (EPS_LOBPCG*)eps->data;

403:   PetscFunctionBegin;
404:   if (bs == PETSC_DEFAULT || bs == PETSC_DECIDE) bs = 0;
405:   else PetscCheck(bs>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid block size %" PetscInt_FMT,bs);
406:   if (ctx->bs != bs) {
407:     ctx->bs = bs;
408:     eps->state = EPS_STATE_INITIAL;
409:   }
410:   PetscFunctionReturn(PETSC_SUCCESS);
411: }

413: /*@
414:    EPSLOBPCGSetBlockSize - Sets the block size of the LOBPCG method.

416:    Logically Collective

418:    Input Parameters:
419: +  eps - the eigenproblem solver context
420: -  bs  - the block size

422:    Options Database Key:
423: .  -eps_lobpcg_blocksize - Sets the block size

425:    Level: advanced

427: .seealso: EPSLOBPCGGetBlockSize()
428: @*/
429: PetscErrorCode EPSLOBPCGSetBlockSize(EPS eps,PetscInt bs)
430: {
431:   PetscFunctionBegin;
434:   PetscTryMethod(eps,"EPSLOBPCGSetBlockSize_C",(EPS,PetscInt),(eps,bs));
435:   PetscFunctionReturn(PETSC_SUCCESS);
436: }

438: static PetscErrorCode EPSLOBPCGGetBlockSize_LOBPCG(EPS eps,PetscInt *bs)
439: {
440:   EPS_LOBPCG *ctx = (EPS_LOBPCG*)eps->data;

442:   PetscFunctionBegin;
443:   *bs = ctx->bs;
444:   PetscFunctionReturn(PETSC_SUCCESS);
445: }

447: /*@
448:    EPSLOBPCGGetBlockSize - Gets the block size used in the LOBPCG method.

450:    Not Collective

452:    Input Parameter:
453: .  eps - the eigenproblem solver context

455:    Output Parameter:
456: .  bs - the block size

458:    Level: advanced

460: .seealso: EPSLOBPCGSetBlockSize()
461: @*/
462: PetscErrorCode EPSLOBPCGGetBlockSize(EPS eps,PetscInt *bs)
463: {
464:   PetscFunctionBegin;
466:   PetscAssertPointer(bs,2);
467:   PetscUseMethod(eps,"EPSLOBPCGGetBlockSize_C",(EPS,PetscInt*),(eps,bs));
468:   PetscFunctionReturn(PETSC_SUCCESS);
469: }

471: static PetscErrorCode EPSLOBPCGSetRestart_LOBPCG(EPS eps,PetscReal restart)
472: {
473:   EPS_LOBPCG *ctx = (EPS_LOBPCG*)eps->data;

475:   PetscFunctionBegin;
476:   if (restart==(PetscReal)PETSC_DEFAULT || restart==(PetscReal)PETSC_DECIDE) restart = 0.9;
477:   PetscCheck(restart>=0.1 && restart<=1.0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"The restart argument %g must be in the range [0.1,1.0]",(double)restart);
478:   if (restart != ctx->restart) {
479:     ctx->restart = restart;
480:     eps->state = EPS_STATE_INITIAL;
481:   }
482:   PetscFunctionReturn(PETSC_SUCCESS);
483: }

485: /*@
486:    EPSLOBPCGSetRestart - Sets the restart parameter for the LOBPCG method.

488:    Logically Collective

490:    Input Parameters:
491: +  eps - the eigenproblem solver context
492: -  restart - the percentage of the block of vectors to force a restart

494:    Options Database Key:
495: .  -eps_lobpcg_restart - Sets the restart parameter

497:    Notes:
498:    The meaning of this parameter is the proportion of vectors within the
499:    current block iterate that must have converged in order to force a
500:    restart with hard locking.
501:    Allowed values are in the range [0.1,1.0]. The default is 0.9.

503:    Level: advanced

505: .seealso: EPSLOBPCGGetRestart()
506: @*/
507: PetscErrorCode EPSLOBPCGSetRestart(EPS eps,PetscReal restart)
508: {
509:   PetscFunctionBegin;
512:   PetscTryMethod(eps,"EPSLOBPCGSetRestart_C",(EPS,PetscReal),(eps,restart));
513:   PetscFunctionReturn(PETSC_SUCCESS);
514: }

516: static PetscErrorCode EPSLOBPCGGetRestart_LOBPCG(EPS eps,PetscReal *restart)
517: {
518:   EPS_LOBPCG *ctx = (EPS_LOBPCG*)eps->data;

520:   PetscFunctionBegin;
521:   *restart = ctx->restart;
522:   PetscFunctionReturn(PETSC_SUCCESS);
523: }

525: /*@
526:    EPSLOBPCGGetRestart - Gets the restart parameter used in the LOBPCG method.

528:    Not Collective

530:    Input Parameter:
531: .  eps - the eigenproblem solver context

533:    Output Parameter:
534: .  restart - the restart parameter

536:    Level: advanced

538: .seealso: EPSLOBPCGSetRestart()
539: @*/
540: PetscErrorCode EPSLOBPCGGetRestart(EPS eps,PetscReal *restart)
541: {
542:   PetscFunctionBegin;
544:   PetscAssertPointer(restart,2);
545:   PetscUseMethod(eps,"EPSLOBPCGGetRestart_C",(EPS,PetscReal*),(eps,restart));
546:   PetscFunctionReturn(PETSC_SUCCESS);
547: }

549: static PetscErrorCode EPSLOBPCGSetLocking_LOBPCG(EPS eps,PetscBool lock)
550: {
551:   EPS_LOBPCG *ctx = (EPS_LOBPCG*)eps->data;

553:   PetscFunctionBegin;
554:   ctx->lock = lock;
555:   PetscFunctionReturn(PETSC_SUCCESS);
556: }

558: /*@
559:    EPSLOBPCGSetLocking - Choose between locking and non-locking variants of
560:    the LOBPCG method.

562:    Logically Collective

564:    Input Parameters:
565: +  eps  - the eigenproblem solver context
566: -  lock - true if the locking variant must be selected

568:    Options Database Key:
569: .  -eps_lobpcg_locking - Sets the locking flag

571:    Notes:
572:    This flag refers to soft locking (converged vectors within the current
573:    block iterate), since hard locking is always used (when nev is larger
574:    than the block size).

576:    Level: advanced

578: .seealso: EPSLOBPCGGetLocking()
579: @*/
580: PetscErrorCode EPSLOBPCGSetLocking(EPS eps,PetscBool lock)
581: {
582:   PetscFunctionBegin;
585:   PetscTryMethod(eps,"EPSLOBPCGSetLocking_C",(EPS,PetscBool),(eps,lock));
586:   PetscFunctionReturn(PETSC_SUCCESS);
587: }

589: static PetscErrorCode EPSLOBPCGGetLocking_LOBPCG(EPS eps,PetscBool *lock)
590: {
591:   EPS_LOBPCG *ctx = (EPS_LOBPCG*)eps->data;

593:   PetscFunctionBegin;
594:   *lock = ctx->lock;
595:   PetscFunctionReturn(PETSC_SUCCESS);
596: }

598: /*@
599:    EPSLOBPCGGetLocking - Gets the locking flag used in the LOBPCG method.

601:    Not Collective

603:    Input Parameter:
604: .  eps - the eigenproblem solver context

606:    Output Parameter:
607: .  lock - the locking flag

609:    Level: advanced

611: .seealso: EPSLOBPCGSetLocking()
612: @*/
613: PetscErrorCode EPSLOBPCGGetLocking(EPS eps,PetscBool *lock)
614: {
615:   PetscFunctionBegin;
617:   PetscAssertPointer(lock,2);
618:   PetscUseMethod(eps,"EPSLOBPCGGetLocking_C",(EPS,PetscBool*),(eps,lock));
619:   PetscFunctionReturn(PETSC_SUCCESS);
620: }

622: static PetscErrorCode EPSView_LOBPCG(EPS eps,PetscViewer viewer)
623: {
624:   EPS_LOBPCG     *ctx = (EPS_LOBPCG*)eps->data;
625:   PetscBool      isascii;

627:   PetscFunctionBegin;
628:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii));
629:   if (isascii) {
630:     PetscCall(PetscViewerASCIIPrintf(viewer,"  block size %" PetscInt_FMT "\n",ctx->bs));
631:     PetscCall(PetscViewerASCIIPrintf(viewer,"  restart parameter=%g (using %" PetscInt_FMT " guard vectors)\n",(double)ctx->restart,ctx->guard));
632:     PetscCall(PetscViewerASCIIPrintf(viewer,"  soft locking %sactivated\n",ctx->lock?"":"de"));
633:   }
634:   PetscFunctionReturn(PETSC_SUCCESS);
635: }

637: static PetscErrorCode EPSSetFromOptions_LOBPCG(EPS eps,PetscOptionItems *PetscOptionsObject)
638: {
639:   PetscBool      lock,flg;
640:   PetscInt       bs;
641:   PetscReal      restart;

643:   PetscFunctionBegin;
644:   PetscOptionsHeadBegin(PetscOptionsObject,"EPS LOBPCG Options");

646:     PetscCall(PetscOptionsInt("-eps_lobpcg_blocksize","Block size","EPSLOBPCGSetBlockSize",20,&bs,&flg));
647:     if (flg) PetscCall(EPSLOBPCGSetBlockSize(eps,bs));

649:     PetscCall(PetscOptionsReal("-eps_lobpcg_restart","Percentage of the block of vectors to force a restart","EPSLOBPCGSetRestart",0.5,&restart,&flg));
650:     if (flg) PetscCall(EPSLOBPCGSetRestart(eps,restart));

652:     PetscCall(PetscOptionsBool("-eps_lobpcg_locking","Choose between locking and non-locking variants","EPSLOBPCGSetLocking",PETSC_TRUE,&lock,&flg));
653:     if (flg) PetscCall(EPSLOBPCGSetLocking(eps,lock));

655:   PetscOptionsHeadEnd();
656:   PetscFunctionReturn(PETSC_SUCCESS);
657: }

659: static PetscErrorCode EPSDestroy_LOBPCG(EPS eps)
660: {
661:   PetscFunctionBegin;
662:   PetscCall(PetscFree(eps->data));
663:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGSetBlockSize_C",NULL));
664:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGGetBlockSize_C",NULL));
665:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGSetRestart_C",NULL));
666:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGGetRestart_C",NULL));
667:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGSetLocking_C",NULL));
668:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGGetLocking_C",NULL));
669:   PetscFunctionReturn(PETSC_SUCCESS);
670: }

672: SLEPC_EXTERN PetscErrorCode EPSCreate_LOBPCG(EPS eps)
673: {
674:   EPS_LOBPCG     *lobpcg;

676:   PetscFunctionBegin;
677:   PetscCall(PetscNew(&lobpcg));
678:   eps->data = (void*)lobpcg;
679:   lobpcg->lock = PETSC_TRUE;

681:   eps->useds = PETSC_TRUE;
682:   eps->categ = EPS_CATEGORY_PRECOND;

684:   eps->ops->solve          = EPSSolve_LOBPCG;
685:   eps->ops->setup          = EPSSetUp_LOBPCG;
686:   eps->ops->setupsort      = EPSSetUpSort_Default;
687:   eps->ops->setfromoptions = EPSSetFromOptions_LOBPCG;
688:   eps->ops->destroy        = EPSDestroy_LOBPCG;
689:   eps->ops->view           = EPSView_LOBPCG;
690:   eps->ops->backtransform  = EPSBackTransform_Default;
691:   eps->ops->setdefaultst   = EPSSetDefaultST_GMRES;

693:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGSetBlockSize_C",EPSLOBPCGSetBlockSize_LOBPCG));
694:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGGetBlockSize_C",EPSLOBPCGGetBlockSize_LOBPCG));
695:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGSetRestart_C",EPSLOBPCGSetRestart_LOBPCG));
696:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGGetRestart_C",EPSLOBPCGGetRestart_LOBPCG));
697:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGSetLocking_C",EPSLOBPCGSetLocking_LOBPCG));
698:   PetscCall(PetscObjectComposeFunction((PetscObject)eps,"EPSLOBPCGGetLocking_C",EPSLOBPCGGetLocking_LOBPCG));
699:   PetscFunctionReturn(PETSC_SUCCESS);
700: }