Actual source code: qslice.c

  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 polynomial eigensolver: "stoar"

 13:    Method: S-TOAR with spectrum slicing for symmetric quadratic eigenproblems

 15:    Algorithm:

 17:        Symmetric Two-Level Orthogonal Arnoldi.

 19:    References:

 21:        [1] C. Campos and J.E. Roman, "Inertia-based spectrum slicing
 22:            for symmetric quadratic eigenvalue problems", Numer. Linear
 23:            Algebra Appl. 27(4):e2293, 2020.
 24: */

 26: #include <slepc/private/pepimpl.h>
 27: #include "../src/pep/impls/krylov/pepkrylov.h"
 28: #include <slepcblaslapack.h>

 30: static PetscBool  cited = PETSC_FALSE;
 31: static const char citation[] =
 32:   "@Article{slepc-slice-qep,\n"
 33:   "   author = \"C. Campos and J. E. Roman\",\n"
 34:   "   title = \"Inertia-based spectrum slicing for symmetric quadratic eigenvalue problems\",\n"
 35:   "   journal = \"Numer. Linear Algebra Appl.\",\n"
 36:   "   volume = \"27\",\n"
 37:   "   number = \"4\",\n"
 38:   "   pages = \"e2293\",\n"
 39:   "   year = \"2020,\"\n"
 40:   "   doi = \"https://doi.org/10.1002/nla.2293\"\n"
 41:   "}\n";

 43: #define SLICE_PTOL PETSC_SQRT_MACHINE_EPSILON

 45: static PetscErrorCode PEPQSliceResetSR(PEP pep)
 46: {
 47:   PEP_STOAR      *ctx=(PEP_STOAR*)pep->data;
 48:   PEP_SR         sr=ctx->sr;
 49:   PEP_shift      s;
 50:   PetscInt       i;

 52:   PetscFunctionBegin;
 53:   if (sr) {
 54:     /* Reviewing list of shifts to free memory */
 55:     s = sr->s0;
 56:     if (s) {
 57:       while (s->neighb[1]) {
 58:         s = s->neighb[1];
 59:         PetscCall(PetscFree(s->neighb[0]));
 60:       }
 61:       PetscCall(PetscFree(s));
 62:     }
 63:     PetscCall(PetscFree(sr->S));
 64:     for (i=0;i<pep->nconv;i++) PetscCall(PetscFree(sr->qinfo[i].q));
 65:     PetscCall(PetscFree(sr->qinfo));
 66:     for (i=0;i<3;i++) PetscCall(VecDestroy(&sr->v[i]));
 67:     PetscCall(EPSDestroy(&sr->eps));
 68:     PetscCall(PetscFree(sr));
 69:   }
 70:   ctx->sr = NULL;
 71:   PetscFunctionReturn(PETSC_SUCCESS);
 72: }

 74: PetscErrorCode PEPReset_STOAR_QSlice(PEP pep)
 75: {
 76:   PEP_STOAR      *ctx=(PEP_STOAR*)pep->data;

 78:   PetscFunctionBegin;
 79:   PetscCall(PEPQSliceResetSR(pep));
 80:   PetscCall(PetscFree(ctx->inertias));
 81:   PetscCall(PetscFree(ctx->shifts));
 82:   PetscFunctionReturn(PETSC_SUCCESS);
 83: }

 85: /*
 86:   PEPQSliceAllocateSolution - Allocate memory storage for common variables such
 87:   as eigenvalues and eigenvectors.
 88: */
 89: static PetscErrorCode PEPQSliceAllocateSolution(PEP pep)
 90: {
 91:   PEP_STOAR      *ctx=(PEP_STOAR*)pep->data;
 92:   PetscInt       k;
 93:   BVType         type;
 94:   Vec            t;
 95:   PEP_SR         sr = ctx->sr;

 97:   PetscFunctionBegin;
 98:   /* allocate space for eigenvalues and friends */
 99:   k = PetscMax(1,sr->numEigs);
100:   PetscCall(PetscFree4(sr->eigr,sr->eigi,sr->errest,sr->perm));
101:   PetscCall(PetscCalloc4(k,&sr->eigr,k,&sr->eigi,k,&sr->errest,k,&sr->perm));
102:   PetscCall(PetscFree(sr->qinfo));
103:   PetscCall(PetscCalloc1(k,&sr->qinfo));

105:   /* allocate sr->V and transfer options from pep->V */
106:   PetscCall(BVDestroy(&sr->V));
107:   PetscCall(BVCreate(PetscObjectComm((PetscObject)pep),&sr->V));
108:   if (!pep->V) PetscCall(PEPGetBV(pep,&pep->V));
109:   if (!((PetscObject)pep->V)->type_name) PetscCall(BVSetType(sr->V,BVMAT));
110:   else {
111:     PetscCall(BVGetType(pep->V,&type));
112:     PetscCall(BVSetType(sr->V,type));
113:   }
114:   PetscCall(STMatCreateVecsEmpty(pep->st,&t,NULL));
115:   PetscCall(BVSetSizesFromVec(sr->V,t,k+1));
116:   PetscCall(VecDestroy(&t));
117:   sr->ld = k;
118:   PetscCall(PetscFree(sr->S));
119:   PetscCall(PetscMalloc1((k+1)*sr->ld*(pep->nmat-1),&sr->S));
120:   PetscFunctionReturn(PETSC_SUCCESS);
121: }

123: /* Convergence test to compute positive Ritz values */
124: static PetscErrorCode ConvergedPositive(EPS eps,PetscScalar eigr,PetscScalar eigi,PetscReal res,PetscReal *errest,void *ctx)
125: {
126:   PetscFunctionBegin;
127:   *errest = (PetscRealPart(eigr)>0.0)?0.0:res;
128:   PetscFunctionReturn(PETSC_SUCCESS);
129: }

131: static PetscErrorCode PEPQSliceMatGetInertia(PEP pep,PetscReal shift,PetscInt *inertia,PetscInt *zeros)
132: {
133:   KSP            ksp,kspr;
134:   PC             pc;
135:   Mat            F;
136:   PetscBool      flg;

138:   PetscFunctionBegin;
139:   if (!pep->solvematcoeffs) PetscCall(PetscMalloc1(pep->nmat,&pep->solvematcoeffs));
140:   if (shift==PETSC_MAX_REAL) { /* Inertia of matrix A[2] */
141:     pep->solvematcoeffs[0] = 0.0; pep->solvematcoeffs[1] = 0.0; pep->solvematcoeffs[2] = 1.0;
142:   } else PetscCall(PEPEvaluateBasis(pep,shift,0,pep->solvematcoeffs,NULL));
143:   PetscCall(STMatSetUp(pep->st,pep->sfactor,pep->solvematcoeffs));
144:   PetscCall(STGetKSP(pep->st,&ksp));
145:   PetscCall(KSPGetPC(ksp,&pc));
146:   PetscCall(PetscObjectTypeCompare((PetscObject)pc,PCREDUNDANT,&flg));
147:   if (flg) {
148:     PetscCall(PCRedundantGetKSP(pc,&kspr));
149:     PetscCall(KSPGetPC(kspr,&pc));
150:   }
151:   PetscCall(PetscObjectTypeCompare((PetscObject)pc,PCTELESCOPE,&flg));
152:   if (flg) {
153:     PetscCall(PCTelescopeGetKSP(pc,&kspr));
154:     PetscCall(KSPGetPC(kspr,&pc));
155:   }
156:   PetscCall(PCFactorGetMatrix(pc,&F));
157:   PetscCall(PCSetUp(pc));
158:   PetscCall(MatGetInertia(F,inertia,zeros,NULL));
159:   PetscFunctionReturn(PETSC_SUCCESS);
160: }

162: static PetscErrorCode PEPQSliceGetInertia(PEP pep,PetscReal shift,PetscInt *inertia,PetscInt *zeros,PetscInt correction)
163: {
164:   KSP            ksp;
165:   Mat            P;
166:   PetscReal      nzshift=0.0,dot;
167:   PetscRandom    rand;
168:   PetscInt       nconv;
169:   PEP_STOAR      *ctx=(PEP_STOAR*)pep->data;
170:   PEP_SR         sr=ctx->sr;

172:   PetscFunctionBegin;
173:   if (shift >= PETSC_MAX_REAL) { /* Right-open interval */
174:     *inertia = 0;
175:   } else if (shift <= PETSC_MIN_REAL) {
176:     *inertia = 0;
177:     if (zeros) *zeros = 0;
178:   } else {
179:     /* If the shift is zero, perturb it to a very small positive value.
180:        The goal is that the nonzero pattern is the same in all cases and reuse
181:        the symbolic factorizations */
182:     nzshift = (shift==0.0)? 10.0/PETSC_MAX_REAL: shift;
183:     PetscCall(PEPQSliceMatGetInertia(pep,nzshift,inertia,zeros));
184:     PetscCall(STSetShift(pep->st,nzshift));
185:   }
186:   if (!correction) {
187:     if (shift >= PETSC_MAX_REAL) *inertia = 2*pep->n;
188:     else if (shift>PETSC_MIN_REAL) {
189:       PetscCall(STGetKSP(pep->st,&ksp));
190:       PetscCall(KSPGetOperators(ksp,&P,NULL));
191:       if (*inertia!=pep->n && !sr->v[0]) {
192:         PetscCall(MatCreateVecs(P,&sr->v[0],NULL));
193:         PetscCall(VecDuplicate(sr->v[0],&sr->v[1]));
194:         PetscCall(VecDuplicate(sr->v[0],&sr->v[2]));
195:         PetscCall(BVGetRandomContext(pep->V,&rand));
196:         PetscCall(VecSetRandom(sr->v[0],rand));
197:       }
198:       if (*inertia<pep->n && *inertia>0) {
199:         if (!sr->eps) {
200:           PetscCall(EPSCreate(PetscObjectComm((PetscObject)pep),&sr->eps));
201:           PetscCall(EPSSetProblemType(sr->eps,EPS_HEP));
202:           PetscCall(EPSSetWhichEigenpairs(sr->eps,EPS_LARGEST_REAL));
203:         }
204:         PetscCall(EPSSetConvergenceTestFunction(sr->eps,ConvergedPositive,NULL,NULL));
205:         PetscCall(EPSSetOperators(sr->eps,P,NULL));
206:         PetscCall(EPSSolve(sr->eps));
207:         PetscCall(EPSGetConverged(sr->eps,&nconv));
208:         PetscCheck(nconv,((PetscObject)pep)->comm,PETSC_ERR_CONV_FAILED,"Inertia computation fails in %g",(double)nzshift);
209:         PetscCall(EPSGetEigenpair(sr->eps,0,NULL,NULL,sr->v[0],sr->v[1]));
210:       }
211:       if (*inertia!=pep->n) {
212:         PetscCall(MatMult(pep->A[1],sr->v[0],sr->v[1]));
213:         PetscCall(MatMult(pep->A[2],sr->v[0],sr->v[2]));
214:         PetscCall(VecAXPY(sr->v[1],2*nzshift,sr->v[2]));
215:         PetscCall(VecDotRealPart(sr->v[1],sr->v[0],&dot));
216:         if (dot>0.0) *inertia = 2*pep->n-*inertia;
217:       }
218:     }
219:   } else if (correction<0) *inertia = 2*pep->n-*inertia;
220:   PetscFunctionReturn(PETSC_SUCCESS);
221: }

223: /*
224:    Check eigenvalue type - used only in non-hyperbolic problems.
225:    All computed eigenvalues must have the same definite type (positive or negative).
226:    If ini=TRUE the type is available in omega, otherwise we compute an eigenvalue
227:    closest to shift and determine its type.
228:  */
229: static PetscErrorCode PEPQSliceCheckEigenvalueType(PEP pep,PetscReal shift,PetscReal omega,PetscBool ini)
230: {
231:   PEP            pep2;
232:   ST             st;
233:   PetscInt       nconv;
234:   PetscScalar    lambda;
235:   PetscReal      dot;
236:   PEP_STOAR      *ctx=(PEP_STOAR*)pep->data;
237:   PEP_SR         sr=ctx->sr;

239:   PetscFunctionBegin;
240:   if (!ini) {
241:     PetscCheck(-(omega/(shift*ctx->alpha+ctx->beta))*sr->type>=0,((PetscObject)pep)->comm,PETSC_ERR_CONV_FAILED,"Different positive/negative type detected in eigenvalue %g",(double)shift);
242:   } else {
243:     PetscCall(PEPCreate(PetscObjectComm((PetscObject)pep),&pep2));
244:     PetscCall(PEPSetOptionsPrefix(pep2,((PetscObject)pep)->prefix));
245:     PetscCall(PEPAppendOptionsPrefix(pep2,"pep_eigenvalue_type_"));
246:     PetscCall(PEPSetTolerances(pep2,PETSC_CURRENT,pep->max_it/4));
247:     PetscCall(PEPSetType(pep2,PEPTOAR));
248:     PetscCall(PEPSetOperators(pep2,pep->nmat,pep->A));
249:     PetscCall(PEPSetWhichEigenpairs(pep2,PEP_TARGET_MAGNITUDE));
250:     PetscCall(PEPGetRG(pep2,&pep2->rg));
251:     PetscCall(RGSetType(pep2->rg,RGINTERVAL));
252: #if defined(PETSC_USE_COMPLEX)
253:     PetscCall(RGIntervalSetEndpoints(pep2->rg,pep->inta,pep->intb,-PETSC_SQRT_MACHINE_EPSILON,PETSC_SQRT_MACHINE_EPSILON));
254: #else
255:     PetscCall(RGIntervalSetEndpoints(pep2->rg,pep->inta,pep->intb,0.0,0.0));
256: #endif
257:     pep2->target = shift;
258:     st = pep2->st;
259:     pep2->st = pep->st;
260:     PetscCall(PEPSolve(pep2));
261:     PetscCall(PEPGetConverged(pep2,&nconv));
262:     if (nconv) {
263:       PetscCall(PEPGetEigenpair(pep2,0,&lambda,NULL,pep2->work[0],NULL));
264:       PetscCall(MatMult(pep->A[1],pep2->work[0],pep2->work[1]));
265:       PetscCall(MatMult(pep->A[2],pep2->work[0],pep2->work[2]));
266:       PetscCall(VecAXPY(pep2->work[1],2.0*lambda*pep->sfactor,pep2->work[2]));
267:       PetscCall(VecDotRealPart(pep2->work[1],pep2->work[0],&dot));
268:       PetscCall(PetscInfo(pep,"lambda=%g, %s type\n",(double)PetscRealPart(lambda),(dot>0.0)?"positive":"negative"));
269:       if (!sr->type) sr->type = (dot>0.0)?1:-1;
270:       else PetscCheck(sr->type*dot>=0.0,((PetscObject)pep)->comm,PETSC_ERR_CONV_FAILED,"Different positive/negative type detected in eigenvalue %g",(double)PetscRealPart(lambda));
271:     }
272:     pep2->st = st;
273:     PetscCall(PEPDestroy(&pep2));
274:   }
275:   PetscFunctionReturn(PETSC_SUCCESS);
276: }

278: static inline PetscErrorCode PEPQSliceDiscriminant(PEP pep,Vec u,Vec w,PetscReal *d,PetscReal *smas,PetscReal *smenos)
279: {
280:   PetscReal      ap,bp,cp,dis;

282:   PetscFunctionBegin;
283:   PetscCall(MatMult(pep->A[0],u,w));
284:   PetscCall(VecDotRealPart(w,u,&cp));
285:   PetscCall(MatMult(pep->A[1],u,w));
286:   PetscCall(VecDotRealPart(w,u,&bp));
287:   PetscCall(MatMult(pep->A[2],u,w));
288:   PetscCall(VecDotRealPart(w,u,&ap));
289:   dis = bp*bp-4*ap*cp;
290:   if (dis>=0.0 && smas) {
291:     if (ap>0) *smas = (-bp+PetscSqrtReal(dis))/(2*ap);
292:     else if (ap<0) *smas = (-bp-PetscSqrtReal(dis))/(2*ap);
293:     else {
294:       if (bp >0) *smas = -cp/bp;
295:       else *smas = PETSC_MAX_REAL;
296:     }
297:   }
298:   if (dis>=0.0 && smenos) {
299:     if (ap>0) *smenos = (-bp-PetscSqrtReal(dis))/(2*ap);
300:     else if (ap<0) *smenos = (-bp+PetscSqrtReal(dis))/(2*ap);
301:     else {
302:       if (bp<0) *smenos = -cp/bp;
303:       else *smenos = PETSC_MAX_REAL;
304:     }
305:   }
306:   if (d) *d = dis;
307:   PetscFunctionReturn(PETSC_SUCCESS);
308: }

310: static inline PetscErrorCode PEPQSliceEvaluateQEP(PEP pep,PetscScalar x,Mat M,MatStructure str)
311: {
312:   PetscFunctionBegin;
313:   PetscCall(MatCopy(pep->A[0],M,SAME_NONZERO_PATTERN));
314:   PetscCall(MatAXPY(M,x,pep->A[1],str));
315:   PetscCall(MatAXPY(M,x*x,pep->A[2],str));
316:   PetscFunctionReturn(PETSC_SUCCESS);
317: }

319: /*@
320:    PEPCheckDefiniteQEP - Determines if a symmetric/Hermitian quadratic eigenvalue problem
321:    is definite or not.

323:    Collective

325:    Input Parameter:
326: .  pep - the polynomial eigensolver context

328:    Output Parameters:
329: +  xi - first computed parameter
330: .  mu - second computed parameter
331: .  definite - flag indicating that the problem is definite
332: -  hyperbolic - flag indicating that the problem is hyperbolic

334:    Notes:
335:    This function is intended for quadratic eigenvalue problems, $Q(\lambda)=K+\lambda C+\lambda^2M$,
336:    with symmetric (or Hermitian) coefficient matrices $K$, $C$, $M$.

338:    On output, the flag `definite` may have the values -1 (meaning that the QEP is not
339:    definite), 1 (if the problem is definite), or 0 if the algorithm was not able to
340:    determine whether the problem is definite or not.

342:    If `definite`=1, the output flag `hyperbolic` informs in a similar way about whether the
343:    problem is hyperbolic or not.

345:    If `definite`=1, the computed values `xi` and `mu` satisfy $Q(\xi)<0$ and $Q(\mu)>0$,
346:    as obtained via the method proposed by {cite:t}`Nie10`. Furthermore, if
347:    `hyperbolic`=1 then only `xi` is computed.

349:    Level: advanced

351: .seealso: [](ch:pep), `PEPSetProblemType()`
352: @*/
353: PetscErrorCode PEPCheckDefiniteQEP(PEP pep,PetscReal *xi,PetscReal *mu,PetscInt *definite,PetscInt *hyperbolic)
354: {
355:   PetscRandom    rand;
356:   Vec            u,w;
357:   PetscReal      d=0.0,s=0.0,sp,mut=0.0,omg=0.0,omgp;
358:   PetscInt       k,its=10,hyp=0,check=0,nconv,inertia,n;
359:   Mat            M=NULL;
360:   MatStructure   str;
361:   EPS            eps;
362:   PetscBool      transform,ptypehyp;

364:   PetscFunctionBegin;
365:   PetscCheck(pep->problem_type==PEP_HERMITIAN || pep->problem_type==PEP_HYPERBOLIC,PetscObjectComm((PetscObject)pep),PETSC_ERR_SUP,"Only available for Hermitian (or hyperbolic) problems");
366:   ptypehyp = (pep->problem_type==PEP_HYPERBOLIC)? PETSC_TRUE: PETSC_FALSE;
367:   if (!pep->st) PetscCall(PEPGetST(pep,&pep->st));
368:   PetscCall(PEPSetDefaultST(pep));
369:   PetscCall(STSetMatrices(pep->st,pep->nmat,pep->A));
370:   PetscCall(MatGetSize(pep->A[0],&n,NULL));
371:   PetscCall(STGetTransform(pep->st,&transform));
372:   PetscCall(STSetTransform(pep->st,PETSC_FALSE));
373:   PetscCall(STSetUp(pep->st));
374:   PetscCall(MatCreateVecs(pep->A[0],&u,&w));
375:   PetscCall(PEPGetBV(pep,&pep->V));
376:   PetscCall(BVGetRandomContext(pep->V,&rand));
377:   PetscCall(VecSetRandom(u,rand));
378:   PetscCall(VecNormalize(u,NULL));
379:   PetscCall(PEPQSliceDiscriminant(pep,u,w,&d,&s,NULL));
380:   if (d<0.0) check = -1;
381:   if (!check) {
382:     PetscCall(EPSCreate(PetscObjectComm((PetscObject)pep),&eps));
383:     PetscCall(EPSSetProblemType(eps,EPS_HEP));
384:     PetscCall(EPSSetWhichEigenpairs(eps,EPS_LARGEST_REAL));
385:     PetscCall(EPSSetTolerances(eps,PetscSqrtReal(PETSC_SQRT_MACHINE_EPSILON),PETSC_DECIDE));
386:     PetscCall(MatDuplicate(pep->A[0],MAT_DO_NOT_COPY_VALUES,&M));
387:     PetscCall(STGetMatStructure(pep->st,&str));
388:   }
389:   for (k=0;k<its&&!check;k++) {
390:     PetscCall(PEPQSliceEvaluateQEP(pep,s,M,str));
391:     PetscCall(EPSSetOperators(eps,M,NULL));
392:     PetscCall(EPSSolve(eps));
393:     PetscCall(EPSGetConverged(eps,&nconv));
394:     if (!nconv) break;
395:     PetscCall(EPSGetEigenpair(eps,0,NULL,NULL,u,w));
396:     sp = s;
397:     PetscCall(PEPQSliceDiscriminant(pep,u,w,&d,&s,&omg));
398:     if (d<0.0) {check = -1; break;}
399:     if (PetscAbsReal((s-sp)/s)<100*PETSC_MACHINE_EPSILON) break;
400:     if (s>sp) hyp = -1;
401:     mut = 2*s-sp;
402:     PetscCall(PEPQSliceMatGetInertia(pep,mut,&inertia,NULL));
403:     if (inertia == n) {check = 1; break;}
404:   }
405:   for (;k<its&&!check;k++) {
406:     mut = (s-omg)/2;
407:     PetscCall(PEPQSliceMatGetInertia(pep,mut,&inertia,NULL));
408:     if (inertia == n) {check = 1; break;}
409:     if (PetscAbsReal((s-omg)/omg)<100*PETSC_MACHINE_EPSILON) break;
410:     PetscCall(PEPQSliceEvaluateQEP(pep,omg,M,str));
411:     PetscCall(EPSSetOperators(eps,M,NULL));
412:     PetscCall(EPSSolve(eps));
413:     PetscCall(EPSGetConverged(eps,&nconv));
414:     if (!nconv) break;
415:     PetscCall(EPSGetEigenpair(eps,0,NULL,NULL,u,w));
416:     omgp = omg;
417:     PetscCall(PEPQSliceDiscriminant(pep,u,w,&d,NULL,&omg));
418:     if (d<0.0) {check = -1; break;}
419:     if (omg<omgp) hyp = -1;
420:   }
421:   if (check==1) *xi = mut;
422:   PetscCheck(hyp!=-1 || !ptypehyp,PetscObjectComm((PetscObject)pep),PETSC_ERR_PLIB,"Problem does not satisfy hyperbolic test; consider removing the hyperbolicity flag");
423:   if (check==1 && hyp==0) {
424:     PetscCall(PEPQSliceMatGetInertia(pep,PETSC_MAX_REAL,&inertia,NULL));
425:     if (inertia == 0) hyp = 1;
426:     else hyp = -1;
427:   }
428:   if (check==1 && hyp!=1) {
429:     check = 0;
430:     PetscCall(EPSSetWhichEigenpairs(eps,EPS_SMALLEST_REAL));
431:     for (;k<its&&!check;k++) {
432:       PetscCall(PEPQSliceEvaluateQEP(pep,s,M,str));
433:       PetscCall(EPSSetOperators(eps,M,NULL));
434:       PetscCall(EPSSolve(eps));
435:       PetscCall(EPSGetConverged(eps,&nconv));
436:       if (!nconv) break;
437:       PetscCall(EPSGetEigenpair(eps,0,NULL,NULL,u,w));
438:       sp = s;
439:       PetscCall(PEPQSliceDiscriminant(pep,u,w,&d,&s,&omg));
440:       if (d<0.0) {check = -1; break;}
441:       if (PetscAbsReal((s-sp)/s)<100*PETSC_MACHINE_EPSILON) break;
442:       mut = 2*s-sp;
443:       PetscCall(PEPQSliceMatGetInertia(pep,mut,&inertia,NULL));
444:       if (inertia == 0) {check = 1; break;}
445:     }
446:     for (;k<its&&!check;k++) {
447:       mut = (s-omg)/2;
448:       PetscCall(PEPQSliceMatGetInertia(pep,mut,&inertia,NULL));
449:       if (inertia == 0) {check = 1; break;}
450:       if (PetscAbsReal((s-omg)/omg)<100*PETSC_MACHINE_EPSILON) break;
451:       PetscCall(PEPQSliceEvaluateQEP(pep,omg,M,str));
452:       PetscCall(EPSSetOperators(eps,M,NULL));
453:       PetscCall(EPSSolve(eps));
454:       PetscCall(EPSGetConverged(eps,&nconv));
455:       if (!nconv) break;
456:       PetscCall(EPSGetEigenpair(eps,0,NULL,NULL,u,w));
457:       PetscCall(PEPQSliceDiscriminant(pep,u,w,&d,NULL,&omg));
458:       if (d<0.0) {check = -1; break;}
459:     }
460:   }
461:   if (check==1) *mu = mut;
462:   *definite = check;
463:   *hyperbolic = hyp;
464:   PetscCall(MatDestroy(&M));
465:   PetscCall(VecDestroy(&u));
466:   PetscCall(VecDestroy(&w));
467:   PetscCall(EPSDestroy(&eps));
468:   PetscCall(STSetTransform(pep->st,transform));
469:   PetscFunctionReturn(PETSC_SUCCESS);
470: }

472: /*
473:    Dummy backtransform operation
474:  */
475: static PetscErrorCode PEPBackTransform_Skip(PEP pep)
476: {
477:   PetscFunctionBegin;
478:   PetscFunctionReturn(PETSC_SUCCESS);
479: }

481: PetscErrorCode PEPSetUp_STOAR_QSlice(PEP pep)
482: {
483:   PEP_STOAR      *ctx=(PEP_STOAR*)pep->data;
484:   PEP_SR         sr;
485:   PetscInt       ld,i,zeros=0;
486:   SlepcSC        sc;
487:   PetscReal      r;

489:   PetscFunctionBegin;
490:   PEPCheckSinvertCayley(pep);
491:   PetscCheck(pep->inta<pep->intb,PetscObjectComm((PetscObject)pep),PETSC_ERR_SUP,"This solver does not support computing all eigenvalues unless you provide a computational interval with PEPSetInterval()");
492:   PetscCheck(pep->intb<PETSC_MAX_REAL || pep->inta>PETSC_MIN_REAL,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_WRONG,"The defined computational interval should have at least one of their sides bounded");
493:   PEPCheckUnsupportedCondition(pep,PEP_FEATURE_STOPPING,PETSC_TRUE," (with spectrum slicing)");
494:   if (pep->tol==(PetscReal)PETSC_DETERMINE) {
495: #if defined(PETSC_USE_REAL_SINGLE)
496:     pep->tol = SLEPC_DEFAULT_TOL;
497: #else
498:     /* use tighter tolerance */
499:     pep->tol = SLEPC_DEFAULT_TOL*1e-2;
500: #endif
501:   }
502:   if (ctx->nev==1) ctx->nev = PetscMin(20,pep->n);  /* nev not set, use default value */
503:   PetscCheck(pep->n<=10 || ctx->nev>=10,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_WRONG,"nev cannot be less than 10 in spectrum slicing runs");
504:   pep->ops->backtransform = PEPBackTransform_Skip;
505:   if (pep->max_it==PETSC_DETERMINE) pep->max_it = 100;

507:   /* create spectrum slicing context and initialize it */
508:   PetscCall(PEPQSliceResetSR(pep));
509:   PetscCall(PetscNew(&sr));
510:   ctx->sr   = sr;
511:   sr->itsKs = 0;
512:   sr->nleap = 0;
513:   sr->sPres = NULL;

515:   PetscCall(PetscFree(pep->solvematcoeffs));
516:   PetscCall(PetscMalloc1(pep->nmat,&pep->solvematcoeffs));
517:   if (!pep->st) PetscCall(PEPGetST(pep,&pep->st));
518:   PetscCall(STSetTransform(pep->st,PETSC_FALSE));
519:   PetscCall(STSetUp(pep->st));

521:   ctx->hyperbolic = (pep->problem_type==PEP_HYPERBOLIC)? PETSC_TRUE: PETSC_FALSE;

523:   /* check presence of ends and finding direction */
524:   if (pep->inta > PETSC_MIN_REAL || pep->intb >= PETSC_MAX_REAL) {
525:     sr->int0 = pep->inta;
526:     sr->int1 = pep->intb;
527:     sr->dir = 1;
528:     if (pep->intb >= PETSC_MAX_REAL) { /* Right-open interval */
529:       sr->hasEnd = PETSC_FALSE;
530:     } else sr->hasEnd = PETSC_TRUE;
531:   } else {
532:     sr->int0 = pep->intb;
533:     sr->int1 = pep->inta;
534:     sr->dir = -1;
535:     sr->hasEnd = PetscNot(pep->inta <= PETSC_MIN_REAL);
536:   }

538:   /* compute inertia0 */
539:   PetscCall(PEPQSliceGetInertia(pep,sr->int0,&sr->inertia0,ctx->detect?&zeros:NULL,ctx->hyperbolic?0:1));
540:   PetscCheck(!zeros || (sr->int0!=pep->inta && sr->int0!=pep->intb),((PetscObject)pep)->comm,PETSC_ERR_USER,"Found singular matrix for the transformed problem in the interval endpoint");
541:   if (!ctx->hyperbolic && ctx->checket) PetscCall(PEPQSliceCheckEigenvalueType(pep,sr->int0,0.0,PETSC_TRUE));

543:   /* compute inertia1 */
544:   PetscCall(PEPQSliceGetInertia(pep,sr->int1,&sr->inertia1,ctx->detect?&zeros:NULL,ctx->hyperbolic?0:1));
545:   PetscCheck(!zeros,((PetscObject)pep)->comm,PETSC_ERR_USER,"Found singular matrix for the transformed problem in an interval endpoint defined by user");
546:   if (!ctx->hyperbolic && ctx->checket && sr->hasEnd) {
547:     PetscCall(PEPQSliceCheckEigenvalueType(pep,sr->int1,0.0,PETSC_TRUE));
548:     PetscCheck(sr->type || sr->inertia1==sr->inertia0,((PetscObject)pep)->comm,PETSC_ERR_CONV_FAILED,"No information of eigenvalue type in interval");
549:     PetscCheck(!sr->type || sr->inertia1!=sr->inertia0,((PetscObject)pep)->comm,PETSC_ERR_CONV_FAILED,"Different positive/negative type detected");
550:     if (sr->dir*(sr->inertia1-sr->inertia0)<0) {
551:       sr->intcorr = -1;
552:       sr->inertia0 = 2*pep->n-sr->inertia0;
553:       sr->inertia1 = 2*pep->n-sr->inertia1;
554:     } else sr->intcorr = 1;
555:   } else {
556:     if (sr->inertia0<=pep->n && sr->inertia1<=pep->n) sr->intcorr = 1;
557:     else if (sr->inertia0>=pep->n && sr->inertia1>=pep->n) sr->intcorr = -1;
558:   }

560:   if (sr->hasEnd) {
561:     sr->dir = -sr->dir; r = sr->int0; sr->int0 = sr->int1; sr->int1 = r;
562:     i = sr->inertia0; sr->inertia0 = sr->inertia1; sr->inertia1 = i;
563:   }

565:   /* number of eigenvalues in interval */
566:   sr->numEigs = (sr->dir)*(sr->inertia1 - sr->inertia0);
567:   PetscCall(PetscInfo(pep,"QSlice setup: allocating for %" PetscInt_FMT " eigenvalues in [%g,%g]\n",sr->numEigs,(double)pep->inta,(double)pep->intb));
568:   if (sr->numEigs) {
569:     PetscCall(PEPQSliceAllocateSolution(pep));
570:     PetscCall(PEPSetDimensions_Default(pep,ctx->nev,&ctx->ncv,&ctx->mpd));
571:     pep->nev = ctx->nev; pep->ncv = ctx->ncv; pep->mpd = ctx->mpd;
572:     ld   = ctx->ncv+2;
573:     PetscCall(DSSetType(pep->ds,DSGHIEP));
574:     PetscCall(DSSetCompact(pep->ds,PETSC_TRUE));
575:     PetscCall(DSSetExtraRow(pep->ds,PETSC_TRUE));
576:     PetscCall(DSAllocate(pep->ds,ld));
577:     PetscCall(DSGetSlepcSC(pep->ds,&sc));
578:     sc->rg            = NULL;
579:     sc->comparison    = SlepcCompareLargestMagnitude;
580:     sc->comparisonctx = NULL;
581:     sc->map           = NULL;
582:     sc->mapobj        = NULL;
583:   } else {pep->ncv = 0; pep->nev = 0; pep->mpd = 0;}
584:   PetscFunctionReturn(PETSC_SUCCESS);
585: }

587: /*
588:    Fills the fields of a shift structure
589: */
590: static PetscErrorCode PEPCreateShift(PEP pep,PetscReal val,PEP_shift neighb0,PEP_shift neighb1)
591: {
592:   PEP_shift      s,*pending2;
593:   PetscInt       i;
594:   PEP_SR         sr;
595:   PEP_STOAR      *ctx=(PEP_STOAR*)pep->data;

597:   PetscFunctionBegin;
598:   sr = ctx->sr;
599:   PetscCall(PetscNew(&s));
600:   s->value = val;
601:   s->neighb[0] = neighb0;
602:   if (neighb0) neighb0->neighb[1] = s;
603:   s->neighb[1] = neighb1;
604:   if (neighb1) neighb1->neighb[0] = s;
605:   s->comp[0] = PETSC_FALSE;
606:   s->comp[1] = PETSC_FALSE;
607:   s->index = -1;
608:   s->neigs = 0;
609:   s->nconv[0] = s->nconv[1] = 0;
610:   s->nsch[0] = s->nsch[1]=0;
611:   /* Inserts in the stack of pending shifts */
612:   /* If needed, the array is resized */
613:   if (sr->nPend >= sr->maxPend) {
614:     sr->maxPend *= 2;
615:     PetscCall(PetscMalloc1(sr->maxPend,&pending2));
616:     for (i=0;i<sr->nPend;i++) pending2[i] = sr->pending[i];
617:     PetscCall(PetscFree(sr->pending));
618:     sr->pending = pending2;
619:   }
620:   sr->pending[sr->nPend++]=s;
621:   PetscFunctionReturn(PETSC_SUCCESS);
622: }

624: /* Provides next shift to be computed */
625: static PetscErrorCode PEPExtractShift(PEP pep)
626: {
627:   PetscInt       iner,zeros=0;
628:   PEP_STOAR      *ctx=(PEP_STOAR*)pep->data;
629:   PEP_SR         sr;
630:   PetscReal      newShift,aux;
631:   PEP_shift      sPres;

633:   PetscFunctionBegin;
634:   sr = ctx->sr;
635:   if (sr->nPend > 0) {
636:     if (sr->dirch) {
637:       aux = sr->int1; sr->int1 = sr->int0; sr->int0 = aux;
638:       iner = sr->inertia1; sr->inertia1 = sr->inertia0; sr->inertia0 = iner;
639:       sr->dir *= -1;
640:       PetscCall(PetscFree(sr->s0->neighb[1]));
641:       PetscCall(PetscFree(sr->s0));
642:       sr->nPend--;
643:       PetscCall(PEPCreateShift(pep,sr->int0,NULL,NULL));
644:       sr->sPrev = NULL;
645:       sr->sPres = sr->pending[--sr->nPend];
646:       pep->target = sr->sPres->value;
647:       sr->s0 = sr->sPres;
648:       pep->reason = PEP_CONVERGED_ITERATING;
649:     } else {
650:       sr->sPrev = sr->sPres;
651:       sr->sPres = sr->pending[--sr->nPend];
652:     }
653:     sPres = sr->sPres;
654:     PetscCall(PEPQSliceGetInertia(pep,sPres->value,&iner,ctx->detect?&zeros:NULL,sr->intcorr));
655:     if (zeros) {
656:       newShift = sPres->value*(1.0+SLICE_PTOL);
657:       if (sr->dir*(sPres->neighb[0] && newShift-sPres->neighb[0]->value) < 0) newShift = (sPres->value+sPres->neighb[0]->value)/2;
658:       else if (sPres->neighb[1] && sr->dir*(sPres->neighb[1]->value-newShift) < 0) newShift = (sPres->value+sPres->neighb[1]->value)/2;
659:       PetscCall(PEPQSliceGetInertia(pep,newShift,&iner,&zeros,sr->intcorr));
660:       PetscCheck(!zeros,((PetscObject)pep)->comm,PETSC_ERR_CONV_FAILED,"Inertia computation fails in %g",(double)newShift);
661:       sPres->value = newShift;
662:     }
663:     sr->sPres->inertia = iner;
664:     pep->target = sr->sPres->value;
665:     pep->reason = PEP_CONVERGED_ITERATING;
666:     pep->its = 0;
667:   } else sr->sPres = NULL;
668:   PetscFunctionReturn(PETSC_SUCCESS);
669: }

671: /*
672:   Obtains value of subsequent shift
673: */
674: static PetscErrorCode PEPGetNewShiftValue(PEP pep,PetscInt side,PetscReal *newS)
675: {
676:   PetscReal lambda,d_prev;
677:   PetscInt  i,idxP;
678:   PEP_SR    sr;
679:   PEP_shift sPres,s;
680:   PEP_STOAR *ctx=(PEP_STOAR*)pep->data;

682:   PetscFunctionBegin;
683:   sr = ctx->sr;
684:   sPres = sr->sPres;
685:   if (sPres->neighb[side]) {
686:   /* Completing a previous interval */
687:     if (!sPres->neighb[side]->neighb[side] && sPres->neighb[side]->nconv[side]==0) { /* One of the ends might be too far from eigenvalues */
688:       if (side) *newS = (sPres->value + PetscRealPart(sr->eigr[sr->perm[sr->indexEig-1]]))/2;
689:       else *newS = (sPres->value + PetscRealPart(sr->eigr[sr->perm[0]]))/2;
690:     } else *newS=(sPres->value + sPres->neighb[side]->value)/2;
691:   } else { /* (Only for side=1). Creating a new interval. */
692:     if (sPres->neigs==0) {/* No value has been accepted*/
693:       if (sPres->neighb[0]) {
694:         /* Multiplying by 10 the previous distance */
695:         *newS = sPres->value + 10*sr->dir*PetscAbsReal(sPres->value - sPres->neighb[0]->value);
696:         sr->nleap++;
697:         /* Stops when the interval is open and no values are found in the last 5 shifts (there might be infinite eigenvalues) */
698:         PetscCheck(sr->hasEnd || sr->nleap<=5,PetscObjectComm((PetscObject)pep),PETSC_ERR_CONV_FAILED,"Unable to compute the wanted eigenvalues with open interval");
699:       } else { /* First shift */
700:         if (pep->nconv != 0) {
701:           /* Unaccepted values give information for next shift */
702:           idxP=0;/* Number of values left from shift */
703:           for (i=0;i<pep->nconv;i++) {
704:             lambda = PetscRealPart(pep->eigr[i]);
705:             if (sr->dir*(lambda - sPres->value) <0) idxP++;
706:             else break;
707:           }
708:           /* Avoiding subtraction of eigenvalues (might be the same).*/
709:           if (idxP>0) {
710:             d_prev = PetscAbsReal(sPres->value - PetscRealPart(pep->eigr[0]))/(idxP+0.3);
711:           } else {
712:             d_prev = PetscAbsReal(sPres->value - PetscRealPart(pep->eigr[pep->nconv-1]))/(pep->nconv+0.3);
713:           }
714:           *newS = sPres->value + (sr->dir*d_prev*pep->nev)/2;
715:           sr->dirch = PETSC_FALSE;
716:         } else { /* No values found, no information for next shift */
717:           PetscCheck(!sr->dirch,PetscObjectComm((PetscObject)pep),PETSC_ERR_PLIB,"First shift renders no information");
718:           sr->dirch = PETSC_TRUE;
719:           *newS = sr->int1;
720:         }
721:       }
722:     } else { /* Accepted values found */
723:       sr->dirch = PETSC_FALSE;
724:       sr->nleap = 0;
725:       /* Average distance of values in previous subinterval */
726:       s = sPres->neighb[0];
727:       while (s && PetscAbs(s->inertia - sPres->inertia)==0) {
728:         s = s->neighb[0];/* Looking for previous shifts with eigenvalues within */
729:       }
730:       if (s) {
731:         d_prev = PetscAbsReal((sPres->value - s->value)/(sPres->inertia - s->inertia));
732:       } else { /* First shift. Average distance obtained with values in this shift */
733:         /* first shift might be too far from first wanted eigenvalue (no values found outside the interval)*/
734:         if (sr->dir*(PetscRealPart(sr->eigr[0])-sPres->value)>0 && PetscAbsReal((PetscRealPart(sr->eigr[sr->indexEig-1]) - PetscRealPart(sr->eigr[0]))/PetscRealPart(sr->eigr[0])) > PetscSqrtReal(pep->tol)) {
735:           d_prev =  PetscAbsReal((PetscRealPart(sr->eigr[sr->indexEig-1]) - PetscRealPart(sr->eigr[0])))/(sPres->neigs+0.3);
736:         } else {
737:           d_prev = PetscAbsReal(PetscRealPart(sr->eigr[sr->indexEig-1]) - sPres->value)/(sPres->neigs+0.3);
738:         }
739:       }
740:       /* Average distance is used for next shift by adding it to value on the right or to shift */
741:       if (sr->dir*(PetscRealPart(sr->eigr[sPres->index + sPres->neigs -1]) - sPres->value)>0) {
742:         *newS = PetscRealPart(sr->eigr[sPres->index + sPres->neigs -1])+ (sr->dir*d_prev*pep->nev)/2;
743:       } else { /* Last accepted value is on the left of shift. Adding to shift */
744:         *newS = sPres->value + (sr->dir*d_prev*pep->nev)/2;
745:       }
746:     }
747:     /* End of interval can not be surpassed */
748:     if (sr->dir*(sr->int1 - *newS) < 0) *newS = sr->int1;
749:   }/* of neighb[side]==null */
750:   PetscFunctionReturn(PETSC_SUCCESS);
751: }

753: /*
754:   Function for sorting an array of real values
755: */
756: static PetscErrorCode sortRealEigenvalues(PetscScalar *r,PetscInt *perm,PetscInt nr,PetscBool prev,PetscInt dir)
757: {
758:   PetscReal re;
759:   PetscInt  i,j,tmp;

761:   PetscFunctionBegin;
762:   if (!prev) for (i=0;i<nr;i++) perm[i] = i;
763:   /* Insertion sort */
764:   for (i=1;i<nr;i++) {
765:     re = PetscRealPart(r[perm[i]]);
766:     j = i-1;
767:     while (j>=0 && dir*(re - PetscRealPart(r[perm[j]])) <= 0) {
768:       tmp = perm[j]; perm[j] = perm[j+1]; perm[j+1] = tmp; j--;
769:     }
770:   }
771:   PetscFunctionReturn(PETSC_SUCCESS);
772: }

774: /* Stores the pairs obtained since the last shift in the global arrays */
775: static PetscErrorCode PEPStoreEigenpairs(PEP pep)
776: {
777:   PEP_STOAR      *ctx=(PEP_STOAR*)pep->data;
778:   PetscReal      lambda,err,*errest;
779:   PetscInt       i,*aux,count=0,ndef,ld,nconv=pep->nconv,d=pep->nmat-1,idx;
780:   PetscBool      iscayley,divide=PETSC_FALSE;
781:   PEP_SR         sr = ctx->sr;
782:   PEP_shift      sPres;
783:   Vec            w,vomega;
784:   Mat            MS;
785:   BV             tV;
786:   PetscScalar    *S,*eigr,*tS,*omega;

788:   PetscFunctionBegin;
789:   sPres = sr->sPres;
790:   sPres->index = sr->indexEig;

792:   if (nconv>sr->ndef0+sr->ndef1) {
793:     /* Back-transform */
794:     PetscCall(STBackTransform(pep->st,nconv,pep->eigr,pep->eigi));
795:     for (i=0;i<nconv;i++) {
796: #if defined(PETSC_USE_COMPLEX)
797:       if (PetscImaginaryPart(pep->eigr[i])) pep->eigr[i] = sr->int0-sr->dir;
798: #else
799:       if (pep->eigi[i]) pep->eigr[i] = sr->int0-sr->dir;
800: #endif
801:     }
802:     PetscCall(PetscObjectTypeCompare((PetscObject)pep->st,STCAYLEY,&iscayley));
803:     /* Sort eigenvalues */
804:     PetscCall(sortRealEigenvalues(pep->eigr,pep->perm,nconv,PETSC_FALSE,sr->dir));
805:     PetscCall(VecCreateSeq(PETSC_COMM_SELF,nconv,&vomega));
806:     PetscCall(BVGetSignature(ctx->V,vomega));
807:     PetscCall(VecGetArray(vomega,&omega));
808:     PetscCall(BVGetSizes(pep->V,NULL,NULL,&ld));
809:     PetscCall(BVTensorGetFactors(ctx->V,NULL,&MS));
810:     PetscCall(MatDenseGetArray(MS,&S));
811:     /* Values stored in global array */
812:     PetscCall(PetscCalloc4(nconv,&eigr,nconv,&errest,nconv*nconv*d,&tS,nconv,&aux));
813:     ndef = sr->ndef0+sr->ndef1;
814:     for (i=0;i<nconv;i++) {
815:       lambda = PetscRealPart(pep->eigr[pep->perm[i]]);
816:       err = pep->errest[pep->perm[i]];
817:       if (sr->dir*(lambda - sPres->ext[0]) > 0 && (sr->dir)*(sPres->ext[1] - lambda) > 0) {/* Valid value */
818:         PetscCheck(sr->indexEig+count-ndef<sr->numEigs,PetscObjectComm((PetscObject)pep),PETSC_ERR_PLIB,"Unexpected error in Spectrum Slicing");
819:         PetscCall(PEPQSliceCheckEigenvalueType(pep,lambda,PetscRealPart(omega[pep->perm[i]]),PETSC_FALSE));
820:         eigr[count] = lambda;
821:         errest[count] = err;
822:         if ((sr->dir*(sPres->value - lambda) > 0) && (sr->dir*(lambda - sPres->ext[0]) > 0)) sPres->nconv[0]++;
823:         if ((sr->dir*(lambda - sPres->value) > 0) && (sr->dir*(sPres->ext[1] - lambda) > 0)) sPres->nconv[1]++;
824:         PetscCall(PetscArraycpy(tS+count*(d*nconv),S+pep->perm[i]*(d*ld),nconv));
825:         PetscCall(PetscArraycpy(tS+count*(d*nconv)+nconv,S+pep->perm[i]*(d*ld)+ld,nconv));
826:         count++;
827:       }
828:     }
829:     PetscCall(VecRestoreArray(vomega,&omega));
830:     PetscCall(VecDestroy(&vomega));
831:     for (i=0;i<count;i++) {
832:       PetscCall(PetscArraycpy(S+i*(d*ld),tS+i*nconv*d,nconv));
833:       PetscCall(PetscArraycpy(S+i*(d*ld)+ld,tS+i*nconv*d+nconv,nconv));
834:     }
835:     PetscCall(MatDenseRestoreArray(MS,&S));
836:     PetscCall(BVTensorRestoreFactors(ctx->V,NULL,&MS));
837:     PetscCall(BVSetActiveColumns(ctx->V,0,count));
838:     PetscCall(BVTensorCompress(ctx->V,count));
839:     if (sr->sPres->nconv[0] && sr->sPres->nconv[1]) {
840:       divide = PETSC_TRUE;
841:       PetscCall(BVTensorGetFactors(ctx->V,NULL,&MS));
842:       PetscCall(MatDenseGetArray(MS,&S));
843:       PetscCall(PetscArrayzero(tS,nconv*nconv*d));
844:       for (i=0;i<count;i++) {
845:         PetscCall(PetscArraycpy(tS+i*nconv*d,S+i*(d*ld),count));
846:         PetscCall(PetscArraycpy(tS+i*nconv*d+nconv,S+i*(d*ld)+ld,count));
847:       }
848:       PetscCall(MatDenseRestoreArray(MS,&S));
849:       PetscCall(BVTensorRestoreFactors(ctx->V,NULL,&MS));
850:       PetscCall(BVSetActiveColumns(pep->V,0,count));
851:       PetscCall(BVDuplicateResize(pep->V,count,&tV));
852:       PetscCall(BVCopy(pep->V,tV));
853:     }
854:     if (sr->sPres->nconv[0]) {
855:       if (divide) {
856:         PetscCall(BVSetActiveColumns(ctx->V,0,sr->sPres->nconv[0]));
857:         PetscCall(BVTensorCompress(ctx->V,sr->sPres->nconv[0]));
858:       }
859:       for (i=0;i<sr->ndef0;i++) aux[i] = sr->idxDef0[i];
860:       for (i=sr->ndef0;i<sr->sPres->nconv[0];i++) aux[i] = sr->indexEig+i-sr->ndef0;
861:       PetscCall(BVTensorGetFactors(ctx->V,NULL,&MS));
862:       PetscCall(MatDenseGetArray(MS,&S));
863:       for (i=0;i<sr->sPres->nconv[0];i++) {
864:         sr->eigr[aux[i]] = eigr[i];
865:         sr->errest[aux[i]] = errest[i];
866:         PetscCall(BVGetColumn(pep->V,i,&w));
867:         PetscCall(BVInsertVec(sr->V,aux[i],w));
868:         PetscCall(BVRestoreColumn(pep->V,i,&w));
869:         idx = sr->ld*d*aux[i];
870:         PetscCall(PetscArrayzero(sr->S+idx,sr->ld*d));
871:         PetscCall(PetscArraycpy(sr->S+idx,S+i*(ld*d),sr->sPres->nconv[0]));
872:         PetscCall(PetscArraycpy(sr->S+idx+sr->ld,S+i*(ld*d)+ld,sr->sPres->nconv[0]));
873:         PetscCall(PetscFree(sr->qinfo[aux[i]].q));
874:         PetscCall(PetscMalloc1(sr->sPres->nconv[0],&sr->qinfo[aux[i]].q));
875:         PetscCall(PetscArraycpy(sr->qinfo[aux[i]].q,aux,sr->sPres->nconv[0]));
876:         sr->qinfo[aux[i]].nq = sr->sPres->nconv[0];
877:       }
878:       PetscCall(MatDenseRestoreArray(MS,&S));
879:       PetscCall(BVTensorRestoreFactors(ctx->V,NULL,&MS));
880:     }

882:     if (sr->sPres->nconv[1]) {
883:       if (divide) {
884:         PetscCall(BVTensorGetFactors(ctx->V,NULL,&MS));
885:         PetscCall(MatDenseGetArray(MS,&S));
886:         for (i=0;i<sr->sPres->nconv[1];i++) {
887:           PetscCall(PetscArraycpy(S+i*(d*ld),tS+(sr->sPres->nconv[0]+i)*nconv*d,count));
888:           PetscCall(PetscArraycpy(S+i*(d*ld)+ld,tS+(sr->sPres->nconv[0]+i)*nconv*d+nconv,count));
889:         }
890:         PetscCall(MatDenseRestoreArray(MS,&S));
891:         PetscCall(BVTensorRestoreFactors(ctx->V,NULL,&MS));
892:         PetscCall(BVSetActiveColumns(pep->V,0,count));
893:         PetscCall(BVCopy(tV,pep->V));
894:         PetscCall(BVSetActiveColumns(ctx->V,0,sr->sPres->nconv[1]));
895:         PetscCall(BVTensorCompress(ctx->V,sr->sPres->nconv[1]));
896:       }
897:       for (i=0;i<sr->ndef1;i++) aux[i] = sr->idxDef1[i];
898:       for (i=sr->ndef1;i<sr->sPres->nconv[1];i++) aux[i] = sr->indexEig+sr->sPres->nconv[0]-sr->ndef0+i-sr->ndef1;
899:       PetscCall(BVTensorGetFactors(ctx->V,NULL,&MS));
900:       PetscCall(MatDenseGetArray(MS,&S));
901:       for (i=0;i<sr->sPres->nconv[1];i++) {
902:         sr->eigr[aux[i]] = eigr[sr->sPres->nconv[0]+i];
903:         sr->errest[aux[i]] = errest[sr->sPres->nconv[0]+i];
904:         PetscCall(BVGetColumn(pep->V,i,&w));
905:         PetscCall(BVInsertVec(sr->V,aux[i],w));
906:         PetscCall(BVRestoreColumn(pep->V,i,&w));
907:         idx = sr->ld*d*aux[i];
908:         PetscCall(PetscArrayzero(sr->S+idx,sr->ld*d));
909:         PetscCall(PetscArraycpy(sr->S+idx,S+i*(ld*d),sr->sPres->nconv[1]));
910:         PetscCall(PetscArraycpy(sr->S+idx+sr->ld,S+i*(ld*d)+ld,sr->sPres->nconv[1]));
911:         PetscCall(PetscFree(sr->qinfo[aux[i]].q));
912:         PetscCall(PetscMalloc1(sr->sPres->nconv[1],&sr->qinfo[aux[i]].q));
913:         PetscCall(PetscArraycpy(sr->qinfo[aux[i]].q,aux,sr->sPres->nconv[1]));
914:         sr->qinfo[aux[i]].nq = sr->sPres->nconv[1];
915:       }
916:       PetscCall(MatDenseRestoreArray(MS,&S));
917:       PetscCall(BVTensorRestoreFactors(ctx->V,NULL,&MS));
918:     }
919:     sPres->neigs = count-sr->ndef0-sr->ndef1;
920:     sr->indexEig += sPres->neigs;
921:     sPres->nconv[0]-= sr->ndef0;
922:     sPres->nconv[1]-= sr->ndef1;
923:     PetscCall(PetscFree4(eigr,errest,tS,aux));
924:   } else {
925:     sPres->neigs = 0;
926:     sPres->nconv[0]= 0;
927:     sPres->nconv[1]= 0;
928:   }
929:   /* Global ordering array updating */
930:   PetscCall(sortRealEigenvalues(sr->eigr,sr->perm,sr->indexEig,PETSC_FALSE,sr->dir));
931:   /* Check for completion */
932:   sPres->comp[0] = PetscNot(sPres->nconv[0] < sPres->nsch[0]);
933:   sPres->comp[1] = PetscNot(sPres->nconv[1] < sPres->nsch[1]);
934:   PetscCheck(sPres->nconv[0]<=sPres->nsch[0] && sPres->nconv[1]<=sPres->nsch[1],PetscObjectComm((PetscObject)pep),PETSC_ERR_PLIB,"Mismatch between number of values found and information from inertia");
935:   if (divide) PetscCall(BVDestroy(&tV));
936:   PetscFunctionReturn(PETSC_SUCCESS);
937: }

939: static PetscErrorCode PEPLookForDeflation(PEP pep)
940: {
941:   PetscReal val;
942:   PetscInt  i,count0=0,count1=0;
943:   PEP_shift sPres;
944:   PetscInt  ini,fin;
945:   PEP_SR    sr;
946:   PEP_STOAR *ctx=(PEP_STOAR*)pep->data;

948:   PetscFunctionBegin;
949:   sr = ctx->sr;
950:   sPres = sr->sPres;

952:   if (sPres->neighb[0]) ini = (sr->dir)*(sPres->neighb[0]->inertia - sr->inertia0);
953:   else ini = 0;
954:   fin = sr->indexEig;
955:   /* Selection of ends for searching new values */
956:   if (!sPres->neighb[0]) sPres->ext[0] = sr->int0;/* First shift */
957:   else sPres->ext[0] = sPres->neighb[0]->value;
958:   if (!sPres->neighb[1]) {
959:     if (sr->hasEnd) sPres->ext[1] = sr->int1;
960:     else sPres->ext[1] = (sr->dir > 0)?PETSC_MAX_REAL:PETSC_MIN_REAL;
961:   } else sPres->ext[1] = sPres->neighb[1]->value;
962:   /* Selection of values between right and left ends */
963:   for (i=ini;i<fin;i++) {
964:     val=PetscRealPart(sr->eigr[sr->perm[i]]);
965:     /* Values to the right of left shift */
966:     if (sr->dir*(val - sPres->ext[1]) < 0) {
967:       if (sr->dir*(val - sPres->value) < 0) count0++;
968:       else count1++;
969:     } else break;
970:   }
971:   /* The number of values on each side are found */
972:   if (sPres->neighb[0]) {
973:     sPres->nsch[0] = (sr->dir)*(sPres->inertia - sPres->neighb[0]->inertia)-count0;
974:     PetscCheck(sPres->nsch[0]>=0,PetscObjectComm((PetscObject)pep),PETSC_ERR_PLIB,"Mismatch between number of values found and information from inertia");
975:   } else sPres->nsch[0] = 0;

977:   if (sPres->neighb[1]) {
978:     sPres->nsch[1] = (sr->dir)*(sPres->neighb[1]->inertia - sPres->inertia) - count1;
979:     PetscCheck(sPres->nsch[1]>=0,PetscObjectComm((PetscObject)pep),PETSC_ERR_PLIB,"Mismatch between number of values found and information from inertia");
980:   } else sPres->nsch[1] = (sr->dir)*(sr->inertia1 - sPres->inertia);

982:   /* Completing vector of indexes for deflation */
983:   for (i=0;i<count0;i++) sr->idxDef0[i] = sr->perm[ini+i];
984:   sr->ndef0 = count0;
985:   for (i=0;i<count1;i++) sr->idxDef1[i] = sr->perm[ini+count0+i];
986:   sr->ndef1 = count1;
987:   PetscFunctionReturn(PETSC_SUCCESS);
988: }

990: /*
991:   Compute a run of Lanczos iterations
992: */
993: static PetscErrorCode PEPSTOARrun_QSlice(PEP pep,PetscReal *a,PetscReal *b,PetscReal *omega,PetscInt k,PetscInt *M,PetscBool *breakdown,PetscBool *symmlost,Vec *t_)
994: {
995:   PEP_STOAR      *ctx = (PEP_STOAR*)pep->data;
996:   PetscInt       i,j,m=*M,l,lock;
997:   PetscInt       lds,d,ld,offq,nqt,ldds;
998:   Vec            v=t_[0],t=t_[1],q=t_[2];
999:   PetscReal      norm,sym=0.0,fro=0.0,*f;
1000:   PetscScalar    *y,*S,sigma;
1001:   PetscBLASInt   j_,one=1;
1002:   PetscBool      lindep;
1003:   Mat            MS;

1005:   PetscFunctionBegin;
1006:   PetscCall(PetscMalloc1(*M,&y));
1007:   PetscCall(BVGetSizes(pep->V,NULL,NULL,&ld));
1008:   PetscCall(BVTensorGetDegree(ctx->V,&d));
1009:   PetscCall(BVGetActiveColumns(pep->V,&lock,&nqt));
1010:   lds = d*ld;
1011:   offq = ld;
1012:   PetscCall(DSGetLeadingDimension(pep->ds,&ldds));

1014:   *breakdown = PETSC_FALSE; /* ----- */
1015:   PetscCall(STGetShift(pep->st,&sigma));
1016:   PetscCall(DSGetDimensions(pep->ds,NULL,&l,NULL,NULL));
1017:   PetscCall(BVSetActiveColumns(ctx->V,0,m));
1018:   PetscCall(BVSetActiveColumns(pep->V,0,nqt));
1019:   for (j=k;j<m;j++) {
1020:     /* apply operator */
1021:     PetscCall(BVTensorGetFactors(ctx->V,NULL,&MS));
1022:     PetscCall(MatDenseGetArray(MS,&S));
1023:     PetscCall(BVGetColumn(pep->V,nqt,&t));
1024:     PetscCall(BVMultVec(pep->V,1.0,0.0,v,S+j*lds));
1025:     PetscCall(MatMult(pep->A[1],v,q));
1026:     PetscCall(MatMult(pep->A[2],v,t));
1027:     PetscCall(VecAXPY(q,sigma*pep->sfactor,t));
1028:     PetscCall(VecScale(q,pep->sfactor));
1029:     PetscCall(BVMultVec(pep->V,1.0,0.0,v,S+offq+j*lds));
1030:     PetscCall(MatMult(pep->A[2],v,t));
1031:     PetscCall(VecAXPY(q,pep->sfactor*pep->sfactor,t));
1032:     PetscCall(STMatSolve(pep->st,q,t));
1033:     PetscCall(VecScale(t,-1.0));
1034:     PetscCall(BVRestoreColumn(pep->V,nqt,&t));

1036:     /* orthogonalize */
1037:     PetscCall(BVOrthogonalizeColumn(pep->V,nqt,S+(j+1)*lds,&norm,&lindep));
1038:     if (!lindep) {
1039:       *(S+(j+1)*lds+nqt) = norm;
1040:       PetscCall(BVScaleColumn(pep->V,nqt,1.0/norm));
1041:       nqt++;
1042:     }
1043:     for (i=0;i<nqt;i++) *(S+(j+1)*lds+offq+i) = *(S+j*lds+i)+sigma*(*(S+(j+1)*lds+i));
1044:     PetscCall(BVSetActiveColumns(pep->V,0,nqt));
1045:     PetscCall(MatDenseRestoreArray(MS,&S));
1046:     PetscCall(BVTensorRestoreFactors(ctx->V,NULL,&MS));

1048:     /* level-2 orthogonalization */
1049:     PetscCall(BVOrthogonalizeColumn(ctx->V,j+1,y,&norm,&lindep));
1050:     a[j] = PetscRealPart(y[j]);
1051:     omega[j+1] = (norm > 0)?1.0:-1.0;
1052:     PetscCall(BVScaleColumn(ctx->V,j+1,1.0/norm));
1053:     b[j] = PetscAbsReal(norm);

1055:     /* check symmetry */
1056:     PetscCall(DSGetArrayReal(pep->ds,DS_MAT_T,&f));
1057:     if (j==k) {
1058:       for (i=l;i<j-1;i++) y[i] = PetscAbsScalar(y[i])-PetscAbsReal(f[2*ldds+i]);
1059:       for (i=0;i<l;i++) y[i] = 0.0;
1060:     }
1061:     PetscCall(DSRestoreArrayReal(pep->ds,DS_MAT_T,&f));
1062:     if (j>0) y[j-1] = PetscAbsScalar(y[j-1])-PetscAbsReal(b[j-1]);
1063:     PetscCall(PetscBLASIntCast(j,&j_));
1064:     sym = SlepcAbs(BLASnrm2_(&j_,y,&one),sym);
1065:     fro = SlepcAbs(fro,SlepcAbs(a[j],b[j]));
1066:     if (j>0) fro = SlepcAbs(fro,b[j-1]);
1067:     if (sym/fro>PetscMax(PETSC_SQRT_MACHINE_EPSILON,10*pep->tol)) {
1068:       *symmlost = PETSC_TRUE;
1069:       *M=j;
1070:       break;
1071:     }
1072:   }
1073:   PetscCall(BVSetActiveColumns(pep->V,lock,nqt));
1074:   PetscCall(BVSetActiveColumns(ctx->V,0,*M));
1075:   PetscCall(PetscFree(y));
1076:   PetscFunctionReturn(PETSC_SUCCESS);
1077: }

1079: static PetscErrorCode PEPSTOAR_QSlice(PEP pep,Mat B)
1080: {
1081:   PEP_STOAR      *ctx = (PEP_STOAR*)pep->data;
1082:   PetscInt       j,k,l,nv=0,ld,ldds,t,nq=0,idx;
1083:   PetscInt       nconv=0,deg=pep->nmat-1,count0=0,count1=0;
1084:   PetscScalar    *om,sigma,*back,*S,*pQ;
1085:   PetscReal      beta,norm=1.0,*omega,*a,*b,eta,lambda;
1086:   PetscBool      breakdown,symmlost=PETSC_FALSE,sinv,falselock=PETSC_TRUE;
1087:   Mat            MS,MQ,D;
1088:   Vec            v,vomega;
1089:   PEP_SR         sr;
1090:   BVOrthogType   otype;
1091:   BVOrthogBlockType obtype;

1093:   PetscFunctionBegin;
1094:   /* Resize if needed for deflating vectors  */
1095:   sr = ctx->sr;
1096:   sigma = sr->sPres->value;
1097:   k = sr->ndef0+sr->ndef1;
1098:   pep->ncv = ctx->ncv+k;
1099:   pep->nev = ctx->nev+k;
1100:   PetscCall(PEPAllocateSolution(pep,3));
1101:   PetscCall(BVDestroy(&ctx->V));
1102:   PetscCall(BVCreateTensor(pep->V,pep->nmat-1,&ctx->V));
1103:   PetscCall(BVGetOrthogonalization(pep->V,&otype,NULL,&eta,&obtype));
1104:   PetscCall(BVSetOrthogonalization(ctx->V,otype,BV_ORTHOG_REFINE_ALWAYS,eta,obtype));
1105:   PetscCall(DSAllocate(pep->ds,pep->ncv+2));
1106:   PetscCall(PetscMalloc1(pep->ncv,&back));
1107:   PetscCall(DSGetLeadingDimension(pep->ds,&ldds));
1108:   PetscCall(BVSetMatrix(ctx->V,B,PETSC_TRUE));
1109:   PetscCheck(ctx->lock,PetscObjectComm((PetscObject)pep),PETSC_ERR_SUP,"A locking variant is needed for spectrum slicing");
1110:   /* undocumented option to use a cheaper locking instead of the true locking */
1111:   PetscCall(PetscOptionsGetBool(NULL,NULL,"-pep_stoar_falselocking",&falselock,NULL));
1112:   PetscCall(PetscObjectTypeCompare((PetscObject)pep->st,STSINVERT,&sinv));
1113:   PetscCall(RGPushScale(pep->rg,sinv?pep->sfactor:1.0/pep->sfactor));
1114:   PetscCall(STScaleShift(pep->st,sinv?pep->sfactor:1.0/pep->sfactor));

1116:   /* Get the starting Arnoldi vector */
1117:   PetscCall(BVSetActiveColumns(pep->V,0,1));
1118:   PetscCall(BVTensorBuildFirstColumn(ctx->V,pep->nini));
1119:   PetscCall(BVSetActiveColumns(ctx->V,0,1));
1120:   if (k) {
1121:     /* Insert deflated vectors */
1122:     PetscCall(BVSetActiveColumns(pep->V,0,0));
1123:     idx = sr->ndef0?sr->idxDef0[0]:sr->idxDef1[0];
1124:     for (j=0;j<k;j++) {
1125:       PetscCall(BVGetColumn(pep->V,j,&v));
1126:       PetscCall(BVCopyVec(sr->V,sr->qinfo[idx].q[j],v));
1127:       PetscCall(BVRestoreColumn(pep->V,j,&v));
1128:     }
1129:     /* Update innerproduct matrix */
1130:     PetscCall(BVSetActiveColumns(ctx->V,0,0));
1131:     PetscCall(BVTensorGetFactors(ctx->V,NULL,&MS));
1132:     PetscCall(BVSetActiveColumns(pep->V,0,k));
1133:     PetscCall(BVTensorRestoreFactors(ctx->V,NULL,&MS));

1135:     PetscCall(BVGetSizes(pep->V,NULL,NULL,&ld));
1136:     PetscCall(BVTensorGetFactors(ctx->V,NULL,&MS));
1137:     PetscCall(MatDenseGetArray(MS,&S));
1138:     for (j=0;j<sr->ndef0;j++) {
1139:       PetscCall(PetscArrayzero(S+j*ld*deg,ld*deg));
1140:       PetscCall(PetscArraycpy(S+j*ld*deg,sr->S+sr->idxDef0[j]*sr->ld*deg,k));
1141:       PetscCall(PetscArraycpy(S+j*ld*deg+ld,sr->S+sr->idxDef0[j]*sr->ld*deg+sr->ld,k));
1142:       pep->eigr[j] = sr->eigr[sr->idxDef0[j]];
1143:       pep->errest[j] = sr->errest[sr->idxDef0[j]];
1144:     }
1145:     for (j=0;j<sr->ndef1;j++) {
1146:       PetscCall(PetscArrayzero(S+(j+sr->ndef0)*ld*deg,ld*deg));
1147:       PetscCall(PetscArraycpy(S+(j+sr->ndef0)*ld*deg,sr->S+sr->idxDef1[j]*sr->ld*deg,k));
1148:       PetscCall(PetscArraycpy(S+(j+sr->ndef0)*ld*deg+ld,sr->S+sr->idxDef1[j]*sr->ld*deg+sr->ld,k));
1149:       pep->eigr[j+sr->ndef0] = sr->eigr[sr->idxDef1[j]];
1150:       pep->errest[j+sr->ndef0] = sr->errest[sr->idxDef1[j]];
1151:     }
1152:     PetscCall(MatDenseRestoreArray(MS,&S));
1153:     PetscCall(BVTensorRestoreFactors(ctx->V,NULL,&MS));
1154:     PetscCall(BVSetActiveColumns(ctx->V,0,k+1));
1155:     PetscCall(VecCreateSeq(PETSC_COMM_SELF,k+1,&vomega));
1156:     PetscCall(VecGetArray(vomega,&om));
1157:     for (j=0;j<k;j++) {
1158:       PetscCall(BVOrthogonalizeColumn(ctx->V,j,NULL,&norm,NULL));
1159:       PetscCall(BVScaleColumn(ctx->V,j,1/norm));
1160:       om[j] = (norm>=0.0)?1.0:-1.0;
1161:     }
1162:     PetscCall(BVTensorGetFactors(ctx->V,NULL,&MS));
1163:     PetscCall(MatDenseGetArray(MS,&S));
1164:     for (j=0;j<deg;j++) {
1165:       PetscCall(BVSetRandomColumn(pep->V,k+j));
1166:       PetscCall(BVOrthogonalizeColumn(pep->V,k+j,S+k*ld*deg+j*ld,&norm,NULL));
1167:       PetscCall(BVScaleColumn(pep->V,k+j,1.0/norm));
1168:       S[k*ld*deg+j*ld+k+j] = norm;
1169:     }
1170:     PetscCall(MatDenseRestoreArray(MS,&S));
1171:     PetscCall(BVSetActiveColumns(pep->V,0,k+deg));
1172:     PetscCall(BVTensorRestoreFactors(ctx->V,NULL,&MS));
1173:     PetscCall(BVOrthogonalizeColumn(ctx->V,k,NULL,&norm,NULL));
1174:     PetscCall(BVScaleColumn(ctx->V,k,1.0/norm));
1175:     om[k] = (norm>=0.0)?1.0:-1.0;
1176:     PetscCall(VecRestoreArray(vomega,&om));
1177:     PetscCall(BVSetSignature(ctx->V,vomega));
1178:     PetscCall(DSGetArrayReal(pep->ds,DS_MAT_T,&a));
1179:     PetscCall(VecGetArray(vomega,&om));
1180:     for (j=0;j<k;j++) a[j] = PetscRealPart(om[j]/(pep->eigr[j]-sigma));
1181:     PetscCall(VecRestoreArray(vomega,&om));
1182:     PetscCall(VecDestroy(&vomega));
1183:     PetscCall(DSRestoreArrayReal(pep->ds,DS_MAT_T,&a));
1184:     PetscCall(DSGetArray(pep->ds,DS_MAT_Q,&pQ));
1185:     PetscCall(PetscArrayzero(pQ,ldds*k));
1186:     for (j=0;j<k;j++) pQ[j+j*ldds] = 1.0;
1187:     PetscCall(DSRestoreArray(pep->ds,DS_MAT_Q,&pQ));
1188:   }
1189:   PetscCall(BVSetActiveColumns(ctx->V,0,k+1));
1190:   PetscCall(DSSetDimensions(pep->ds,k+1,PETSC_DETERMINE,PETSC_DETERMINE));
1191:   PetscCall(DSGetMatAndColumn(pep->ds,DS_MAT_D,0,&D,&vomega));
1192:   PetscCall(BVGetSignature(ctx->V,vomega));
1193:   PetscCall(DSRestoreMatAndColumn(pep->ds,DS_MAT_D,0,&D,&vomega));

1195:   PetscCall(PetscInfo(pep,"Start STOAR: sigma=%g in [%g,%g], for deflation: left=%" PetscInt_FMT " right=%" PetscInt_FMT ", searching: left=%" PetscInt_FMT " right=%" PetscInt_FMT "\n",(double)sr->sPres->value,(double)(sr->sPres->neighb[0]?sr->sPres->neighb[0]->value:sr->int0),(double)(sr->sPres->neighb[1]?sr->sPres->neighb[1]->value:sr->int1),sr->ndef0,sr->ndef1,sr->sPres->nsch[0],sr->sPres->nsch[1]));

1197:   /* Restart loop */
1198:   l = 0;
1199:   pep->nconv = k;
1200:   while (pep->reason == PEP_CONVERGED_ITERATING) {
1201:     pep->its++;
1202:     PetscCall(DSGetArrayReal(pep->ds,DS_MAT_T,&a));
1203:     b = a+ldds;
1204:     PetscCall(DSGetArrayReal(pep->ds,DS_MAT_D,&omega));

1206:     /* Compute an nv-step Lanczos factorization */
1207:     nv = PetscMin(pep->nconv+pep->mpd,pep->ncv);
1208:     PetscCall(PEPSTOARrun_QSlice(pep,a,b,omega,pep->nconv+l,&nv,&breakdown,&symmlost,pep->work));
1209:     beta = b[nv-1];
1210:     if (symmlost && nv==pep->nconv+l) {
1211:       pep->reason = PEP_DIVERGED_SYMMETRY_LOST;
1212:       pep->nconv = nconv;
1213:       PetscCall(PetscInfo(pep,"Symmetry lost in STOAR sigma=%g nconv=%" PetscInt_FMT "\n",(double)sr->sPres->value,nconv));
1214:       if (falselock || !ctx->lock) {
1215:         PetscCall(BVSetActiveColumns(ctx->V,0,pep->nconv));
1216:         PetscCall(BVTensorCompress(ctx->V,0));
1217:       }
1218:       break;
1219:     }
1220:     PetscCall(DSRestoreArrayReal(pep->ds,DS_MAT_T,&a));
1221:     PetscCall(DSRestoreArrayReal(pep->ds,DS_MAT_D,&omega));
1222:     PetscCall(DSSetDimensions(pep->ds,nv,pep->nconv,pep->nconv+l));
1223:     if (l==0) PetscCall(DSSetState(pep->ds,DS_STATE_INTERMEDIATE));
1224:     else PetscCall(DSSetState(pep->ds,DS_STATE_RAW));

1226:     /* Solve projected problem */
1227:     PetscCall(DSSolve(pep->ds,pep->eigr,pep->eigi));
1228:     PetscCall(DSSort(pep->ds,pep->eigr,pep->eigi,NULL,NULL,NULL));
1229:     PetscCall(DSUpdateExtraRow(pep->ds));
1230:     PetscCall(DSSynchronize(pep->ds,pep->eigr,pep->eigi));

1232:     /* Check convergence */
1233:     /* PetscCall(PEPSTOARpreKConvergence(pep,nv,&norm,pep->work));*/
1234:     norm = 1.0;
1235:     PetscCall(DSGetDimensions(pep->ds,NULL,NULL,NULL,&t));
1236:     PetscCall(PEPKrylovConvergence(pep,PETSC_FALSE,pep->nconv,t-pep->nconv,PetscAbsReal(beta)*norm,&k));
1237:     PetscCall((*pep->stopping)(pep,pep->its,pep->max_it,k,pep->nev,&pep->reason,pep->stoppingctx));
1238:     for (j=0;j<k;j++) back[j] = pep->eigr[j];
1239:     PetscCall(STBackTransform(pep->st,k,back,pep->eigi));
1240:     count0=count1=0;
1241:     for (j=0;j<k;j++) {
1242:       lambda = PetscRealPart(back[j]);
1243:       if ((sr->dir*(sr->sPres->value - lambda) > 0) && (sr->dir*(lambda - sr->sPres->ext[0]) > 0)) count0++;
1244:       if ((sr->dir*(lambda - sr->sPres->value) > 0) && (sr->dir*(sr->sPres->ext[1] - lambda) > 0)) count1++;
1245:     }
1246:     if ((count0-sr->ndef0 >= sr->sPres->nsch[0]) && (count1-sr->ndef1 >= sr->sPres->nsch[1])) pep->reason = PEP_CONVERGED_TOL;
1247:     /* Update l */
1248:     if (pep->reason != PEP_CONVERGED_ITERATING || breakdown) l = 0;
1249:     else {
1250:       l = PetscMax(1,(PetscInt)((nv-k)/2));
1251:       l = PetscMin(l,t);
1252:       PetscCall(DSGetTruncateSize(pep->ds,k,t,&l));
1253:       if (!breakdown) {
1254:         /* Prepare the Rayleigh quotient for restart */
1255:         PetscCall(DSTruncate(pep->ds,k+l,PETSC_FALSE));
1256:       }
1257:     }
1258:     nconv = k;
1259:     if (!ctx->lock && pep->reason == PEP_CONVERGED_ITERATING && !breakdown) { l += k; k = 0; } /* non-locking variant: reset no. of converged pairs */
1260:     if (l) PetscCall(PetscInfo(pep,"Preparing to restart keeping l=%" PetscInt_FMT " vectors\n",l));

1262:     /* Update S */
1263:     PetscCall(DSGetMat(pep->ds,DS_MAT_Q,&MQ));
1264:     PetscCall(BVMultInPlace(ctx->V,MQ,pep->nconv,k+l));
1265:     PetscCall(DSRestoreMat(pep->ds,DS_MAT_Q,&MQ));

1267:     /* Copy last column of S */
1268:     PetscCall(BVCopyColumn(ctx->V,nv,k+l));
1269:     PetscCall(BVSetActiveColumns(ctx->V,0,k+l));
1270:     if (k+l) {
1271:       PetscCall(DSSetDimensions(pep->ds,k+l,PETSC_DETERMINE,PETSC_DETERMINE));
1272:       PetscCall(DSGetMatAndColumn(pep->ds,DS_MAT_D,0,&D,&vomega));
1273:       PetscCall(BVSetSignature(ctx->V,vomega));
1274:       PetscCall(DSRestoreMatAndColumn(pep->ds,DS_MAT_D,0,&D,&vomega));
1275:     }

1277:     if (breakdown && pep->reason == PEP_CONVERGED_ITERATING) {
1278:       /* stop if breakdown */
1279:       PetscCall(PetscInfo(pep,"Breakdown TOAR method (it=%" PetscInt_FMT " norm=%g)\n",pep->its,(double)beta));
1280:       pep->reason = PEP_DIVERGED_BREAKDOWN;
1281:     }
1282:     if (pep->reason != PEP_CONVERGED_ITERATING) l--;
1283:     PetscCall(BVGetActiveColumns(pep->V,NULL,&nq));
1284:     if (k+l+deg<=nq) {
1285:       PetscCall(BVSetActiveColumns(ctx->V,pep->nconv,k+l+1));
1286:       if (!falselock && ctx->lock) PetscCall(BVTensorCompress(ctx->V,k-pep->nconv));
1287:       else PetscCall(BVTensorCompress(ctx->V,0));
1288:     }
1289:     pep->nconv = k;
1290:     PetscCall(PEPMonitor(pep,pep->its,nconv,pep->eigr,pep->eigi,pep->errest,nv));
1291:   }
1292:   sr->itsKs += pep->its;
1293:   if (pep->nconv>0) {
1294:     PetscCall(BVSetActiveColumns(ctx->V,0,pep->nconv));
1295:     PetscCall(BVGetActiveColumns(pep->V,NULL,&nq));
1296:     PetscCall(BVSetActiveColumns(pep->V,0,nq));
1297:     if (nq>pep->nconv) {
1298:       PetscCall(BVTensorCompress(ctx->V,pep->nconv));
1299:       PetscCall(BVSetActiveColumns(pep->V,0,pep->nconv));
1300:     }
1301:     for (j=0;j<pep->nconv;j++) {
1302:       pep->eigr[j] *= pep->sfactor;
1303:       pep->eigi[j] *= pep->sfactor;
1304:     }
1305:   }
1306:   PetscCall(PetscInfo(pep,"Finished STOAR: nconv=%" PetscInt_FMT " (deflated=%" PetscInt_FMT ", left=%" PetscInt_FMT ", right=%" PetscInt_FMT ")\n",pep->nconv,sr->ndef0+sr->ndef1,count0-sr->ndef0,count1-sr->ndef1));
1307:   PetscCall(STScaleShift(pep->st,sinv?1.0/pep->sfactor:pep->sfactor));
1308:   PetscCall(RGPopScale(pep->rg));

1310:   PetscCheck(pep->reason!=PEP_DIVERGED_SYMMETRY_LOST || nconv>=sr->ndef0+sr->ndef1,PetscObjectComm((PetscObject)pep),PETSC_ERR_PLIB,"Symmetry lost at sigma=%g",(double)sr->sPres->value);
1311:   if (pep->reason == PEP_DIVERGED_SYMMETRY_LOST && nconv==sr->ndef0+sr->ndef1) {
1312:     PetscCheck(++sr->symmlost<=10,PetscObjectComm((PetscObject)pep),PETSC_ERR_PLIB,"Symmetry lost at sigma=%g",(double)sr->sPres->value);
1313:   } else sr->symmlost = 0;

1315:   PetscCall(DSTruncate(pep->ds,pep->nconv,PETSC_TRUE));
1316:   PetscCall(PetscFree(back));
1317:   PetscFunctionReturn(PETSC_SUCCESS);
1318: }

1320: static PetscErrorCode PEPQSliceGetInertias(PEP pep,PetscInt *n,PetscReal **shifts,PetscInt **inertias)
1321: {
1322:   PEP_STOAR      *ctx=(PEP_STOAR*)pep->data;
1323:   PEP_SR          sr=ctx->sr;
1324:   PetscInt        i=0,j,tmpi;
1325:   PetscReal       v,tmpr;
1326:   PEP_shift       s;

1328:   PetscFunctionBegin;
1329:   PetscCheck(pep->state,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_WRONGSTATE,"Must call PEPSetUp() first");
1330:   PetscCheck(sr,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see PEPSetInterval()");
1331:   if (!sr->s0) {  /* PEPSolve not called yet */
1332:     *n = 2;
1333:   } else {
1334:     *n = 1;
1335:     s = sr->s0;
1336:     while (s) {
1337:       (*n)++;
1338:       s = s->neighb[1];
1339:     }
1340:   }
1341:   PetscCall(PetscMalloc1(*n,shifts));
1342:   PetscCall(PetscMalloc1(*n,inertias));
1343:   if (!sr->s0) {  /* PEPSolve not called yet */
1344:     (*shifts)[0]   = sr->int0;
1345:     (*shifts)[1]   = sr->int1;
1346:     (*inertias)[0] = sr->inertia0;
1347:     (*inertias)[1] = sr->inertia1;
1348:   } else {
1349:     s = sr->s0;
1350:     while (s) {
1351:       (*shifts)[i]     = s->value;
1352:       (*inertias)[i++] = s->inertia;
1353:       s = s->neighb[1];
1354:     }
1355:     (*shifts)[i]   = sr->int1;
1356:     (*inertias)[i] = sr->inertia1;
1357:   }
1358:   /* remove possible duplicate in last position */
1359:   if ((*shifts)[(*n)-1]==(*shifts)[(*n)-2]) (*n)--;
1360:   /* sort result */
1361:   for (i=0;i<*n;i++) {
1362:     v = (*shifts)[i];
1363:     for (j=i+1;j<*n;j++) {
1364:       if (v > (*shifts)[j]) {
1365:         SlepcSwap((*shifts)[i],(*shifts)[j],tmpr);
1366:         SlepcSwap((*inertias)[i],(*inertias)[j],tmpi);
1367:         v = (*shifts)[i];
1368:       }
1369:     }
1370:   }
1371:   PetscFunctionReturn(PETSC_SUCCESS);
1372: }

1374: PetscErrorCode PEPSolve_STOAR_QSlice(PEP pep)
1375: {
1376:   PetscInt       i,j,ti,deg=pep->nmat-1;
1377:   PetscReal      newS;
1378:   PEP_STOAR      *ctx=(PEP_STOAR*)pep->data;
1379:   PEP_SR         sr=ctx->sr;
1380:   Mat            S,B;
1381:   PetscScalar    *pS;

1383:   PetscFunctionBegin;
1384:   PetscCall(PetscCitationsRegister(citation,&cited));

1386:   /* Only with eigenvalues present in the interval ...*/
1387:   if (sr->numEigs==0) {
1388:     pep->reason = PEP_CONVERGED_TOL;
1389:     PetscFunctionReturn(PETSC_SUCCESS);
1390:   }

1392:   /* Inner product matrix */
1393:   PetscCall(PEPSTOARSetUpInnerMatrix(pep,&B));

1395:   /* Array of pending shifts */
1396:   sr->maxPend = 100; /* Initial size */
1397:   sr->nPend = 0;
1398:   PetscCall(PetscMalloc1(sr->maxPend,&sr->pending));
1399:   PetscCall(PEPCreateShift(pep,sr->int0,NULL,NULL));
1400:   /* extract first shift */
1401:   sr->sPrev = NULL;
1402:   sr->sPres = sr->pending[--sr->nPend];
1403:   sr->sPres->inertia = sr->inertia0;
1404:   pep->target = sr->sPres->value;
1405:   sr->s0 = sr->sPres;
1406:   sr->indexEig = 0;

1408:   for (i=0;i<sr->numEigs;i++) {
1409:     sr->eigr[i]   = 0.0;
1410:     sr->eigi[i]   = 0.0;
1411:     sr->errest[i] = 0.0;
1412:     sr->perm[i]   = i;
1413:   }
1414:   /* Vectors for deflation */
1415:   PetscCall(PetscMalloc2(sr->numEigs,&sr->idxDef0,sr->numEigs,&sr->idxDef1));
1416:   sr->indexEig = 0;
1417:   while (sr->sPres) {
1418:     /* Search for deflation */
1419:     PetscCall(PEPLookForDeflation(pep));
1420:     /* KrylovSchur */
1421:     PetscCall(PEPSTOAR_QSlice(pep,B));

1423:     PetscCall(PEPStoreEigenpairs(pep));
1424:     /* Select new shift */
1425:     if (!sr->sPres->comp[1]) {
1426:       PetscCall(PEPGetNewShiftValue(pep,1,&newS));
1427:       PetscCall(PEPCreateShift(pep,newS,sr->sPres,sr->sPres->neighb[1]));
1428:     }
1429:     if (!sr->sPres->comp[0]) {
1430:       /* Completing earlier interval */
1431:       PetscCall(PEPGetNewShiftValue(pep,0,&newS));
1432:       PetscCall(PEPCreateShift(pep,newS,sr->sPres->neighb[0],sr->sPres));
1433:     }
1434:     /* Preparing for a new search of values */
1435:     PetscCall(PEPExtractShift(pep));
1436:   }

1438:   /* Updating pep values prior to exit */
1439:   PetscCall(PetscFree2(sr->idxDef0,sr->idxDef1));
1440:   PetscCall(PetscFree(sr->pending));
1441:   pep->nconv  = sr->indexEig;
1442:   pep->reason = PEP_CONVERGED_TOL;
1443:   pep->its    = sr->itsKs;
1444:   pep->nev    = sr->indexEig;
1445:   PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,pep->nconv,pep->nconv,NULL,&S));
1446:   PetscCall(MatDenseGetArray(S,&pS));
1447:   for (i=0;i<pep->nconv;i++) {
1448:     for (j=0;j<sr->qinfo[i].nq;j++) pS[i*pep->nconv+sr->qinfo[i].q[j]] = *(sr->S+i*sr->ld*deg+j);
1449:   }
1450:   PetscCall(MatDenseRestoreArray(S,&pS));
1451:   PetscCall(BVSetActiveColumns(sr->V,0,pep->nconv));
1452:   PetscCall(BVMultInPlace(sr->V,S,0,pep->nconv));
1453:   PetscCall(MatDestroy(&S));
1454:   PetscCall(BVDestroy(&pep->V));
1455:   pep->V = sr->V;
1456:   PetscCall(PetscFree4(pep->eigr,pep->eigi,pep->errest,pep->perm));
1457:   pep->eigr   = sr->eigr;
1458:   pep->eigi   = sr->eigi;
1459:   pep->perm   = sr->perm;
1460:   pep->errest = sr->errest;
1461:   if (sr->dir<0) {
1462:     for (i=0;i<pep->nconv/2;i++) {
1463:       ti = sr->perm[i]; sr->perm[i] = sr->perm[pep->nconv-1-i]; sr->perm[pep->nconv-1-i] = ti;
1464:     }
1465:   }
1466:   PetscCall(PetscFree(ctx->inertias));
1467:   PetscCall(PetscFree(ctx->shifts));
1468:   PetscCall(MatDestroy(&B));
1469:   PetscCall(PEPQSliceGetInertias(pep,&ctx->nshifts,&ctx->shifts,&ctx->inertias));
1470:   PetscFunctionReturn(PETSC_SUCCESS);
1471: }