Actual source code: nciss.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 eigensolver: "ciss"

 13:    Method: Contour Integral Spectral Slicing

 15:    Algorithm:

 17:        Contour integral based on Sakurai-Sugiura method to construct a
 18:        subspace, with various eigenpair extractions (Rayleigh-Ritz,
 19:        explicit moment).

 21:    Based on code contributed by Y. Maeda, T. Sakurai.

 23:    References:

 25:        [1] J. Asakura, T. Sakurai, H. Tadano, T. Ikegami, K. Kimura, "A
 26:            numerical method for nonlinear eigenvalue problems using contour
 27:            integrals", JSIAM Lett. 1:52-55, 2009.

 29:        [2] S. Yokota and T. Sakurai, "A projection method for nonlinear
 30:            eigenvalue problems using contour integrals", JSIAM Lett.
 31:            5:41-44, 2013.
 32: */

 34: #include <slepc/private/nepimpl.h>
 35: #include <slepc/private/slepccontour.h>

 37: typedef struct _n_nep_ciss_project *NEP_CISS_PROJECT;
 38: typedef struct {
 39:   /* parameters */
 40:   PetscInt          N;             /* number of integration points (32) */
 41:   PetscInt          L;             /* block size (16) */
 42:   PetscInt          M;             /* moment degree (N/4 = 4) */
 43:   PetscReal         delta;         /* threshold of singular value (1e-12) */
 44:   PetscInt          L_max;         /* maximum number of columns of the source matrix V */
 45:   PetscReal         spurious_threshold; /* discard spurious eigenpairs */
 46:   PetscBool         isreal;        /* T(z) is real for real z */
 47:   PetscInt          npart;         /* number of partitions */
 48:   PetscInt          refine_inner;
 49:   PetscInt          refine_blocksize;
 50:   NEPCISSExtraction extraction;
 51:   /* private data */
 52:   SlepcContourData  contour;
 53:   PetscReal         *sigma;        /* threshold for numerical rank */
 54:   PetscScalar       *weight;
 55:   PetscScalar       *omega;
 56:   PetscScalar       *pp;
 57:   BV                V;
 58:   BV                S;
 59:   BV                Y;
 60:   PetscBool         useconj;
 61:   Mat               J;             /* auxiliary matrix when using subcomm */
 62:   BV                pV;
 63:   PetscObjectId     rgid;
 64:   PetscObjectState  rgstate;
 65: } NEP_CISS;

 67: struct _n_nep_ciss_project {
 68:   NEP  nep;
 69:   BV   Q;
 70: };

 72: static PetscErrorCode NEPContourDSComputeMatrix(DS ds,PetscScalar lambda,PetscBool deriv,DSMatType mat,void *ctx)
 73: {
 74:   NEP_CISS_PROJECT proj = (NEP_CISS_PROJECT)ctx;
 75:   Mat              M,fun;

 77:   PetscFunctionBegin;
 78:   if (!deriv) {
 79:     PetscCall(NEPComputeFunction(proj->nep,lambda,proj->nep->function,proj->nep->function));
 80:     fun = proj->nep->function;
 81:   } else {
 82:     PetscCall(NEPComputeJacobian(proj->nep,lambda,proj->nep->jacobian));
 83:     fun = proj->nep->jacobian;
 84:   }
 85:   PetscCall(DSGetMat(ds,mat,&M));
 86:   PetscCall(BVMatProject(proj->Q,fun,proj->Q,M));
 87:   PetscCall(DSRestoreMat(ds,mat,&M));
 88:   PetscFunctionReturn(PETSC_SUCCESS);
 89: }

 91: static PetscErrorCode NEPComputeFunctionSubcomm(NEP nep,PetscScalar lambda,Mat T,Mat P,PetscBool deriv)
 92: {
 93:   PetscInt       i;
 94:   PetscScalar    alpha;
 95:   NEP_CISS       *ctx = (NEP_CISS*)nep->data;

 97:   PetscFunctionBegin;
 98:   PetscAssert(nep->fui!=NEP_USER_INTERFACE_CALLBACK,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_WRONGSTATE,"Should not arrive here with callbacks");
 99:   PetscCall(MatZeroEntries(T));
100:   if (!deriv && T != P) PetscCall(MatZeroEntries(P));
101:   for (i=0;i<nep->nt;i++) {
102:     if (!deriv) PetscCall(FNEvaluateFunction(nep->f[i],lambda,&alpha));
103:     else PetscCall(FNEvaluateDerivative(nep->f[i],lambda,&alpha));
104:     PetscCall(MatAXPY(T,alpha,ctx->contour->pA[i],nep->mstr));
105:     if (!deriv && T != P) PetscCall(MatAXPY(P,alpha,ctx->contour->pP[i],nep->mstrp));
106:   }
107:   PetscFunctionReturn(PETSC_SUCCESS);
108: }

110: /*
111:   Set up KSP solvers for every integration point
112: */
113: static PetscErrorCode NEPCISSSetUp(NEP nep,Mat T,Mat P)
114: {
115:   NEP_CISS         *ctx = (NEP_CISS*)nep->data;
116:   SlepcContourData contour;
117:   PetscInt         i,p_id;
118:   Mat              Amat,Pmat;

120:   PetscFunctionBegin;
121:   if (!ctx->contour || !ctx->contour->ksp) PetscCall(NEPCISSGetKSPs(nep,NULL,NULL));
122:   contour = ctx->contour;
123:   PetscAssert(ctx->contour && ctx->contour->ksp,PetscObjectComm((PetscObject)nep),PETSC_ERR_PLIB,"Something went wrong with NEPCISSGetKSPs()");
124:   for (i=0;i<contour->npoints;i++) {
125:     p_id = i*contour->subcomm->n + contour->subcomm->color;
126:     PetscCall(MatDuplicate(T,MAT_DO_NOT_COPY_VALUES,&Amat));
127:     if (T != P) PetscCall(MatDuplicate(P,MAT_DO_NOT_COPY_VALUES,&Pmat)); else Pmat = Amat;
128:     if (contour->subcomm->n == 1 || nep->fui==NEP_USER_INTERFACE_CALLBACK) PetscCall(NEPComputeFunction(nep,ctx->omega[p_id],Amat,Pmat));
129:     else PetscCall(NEPComputeFunctionSubcomm(nep,ctx->omega[p_id],Amat,Pmat,PETSC_FALSE));
130:     PetscCall(NEP_KSPSetOperators(contour->ksp[i],Amat,Pmat));
131:     PetscCall(MatDestroy(&Amat));
132:     if (T != P) PetscCall(MatDestroy(&Pmat));
133:   }
134:   PetscFunctionReturn(PETSC_SUCCESS);
135: }

137: /*
138:   Y_i = F(z_i)^{-1}Fp(z_i)V for every integration point, Y=[Y_i] is in the context
139: */
140: static PetscErrorCode NEPCISSSolve(NEP nep,Mat dT,BV V,PetscInt L_start,PetscInt L_end)
141: {
142:   NEP_CISS         *ctx = (NEP_CISS*)nep->data;
143:   SlepcContourData contour = ctx->contour;
144:   PetscInt         i,p_id;
145:   Mat              MV,BMV=NULL,MC;

147:   PetscFunctionBegin;
148:   PetscCall(BVSetActiveColumns(V,L_start,L_end));
149:   PetscCall(BVGetMat(V,&MV));
150:   for (i=0;i<contour->npoints;i++) {
151:     p_id = i*contour->subcomm->n + contour->subcomm->color;
152:     if (contour->subcomm->n==1 || nep->fui==NEP_USER_INTERFACE_CALLBACK) PetscCall(NEPComputeJacobian(nep,ctx->omega[p_id],dT));
153:     else PetscCall(NEPComputeFunctionSubcomm(nep,ctx->omega[p_id],dT,NULL,PETSC_TRUE));
154:     PetscCall(BVSetActiveColumns(ctx->Y,i*ctx->L+L_start,i*ctx->L+L_end));
155:     PetscCall(BVGetMat(ctx->Y,&MC));
156:     if (!i) {
157:       PetscCall(MatProductCreate(dT,MV,NULL,&BMV));
158:       PetscCall(MatProductSetType(BMV,MATPRODUCT_AB));
159:       PetscCall(MatProductSetFromOptions(BMV));
160:       PetscCall(MatProductSymbolic(BMV));
161:     }
162:     PetscCall(MatProductNumeric(BMV));
163:     PetscCall(KSPMatSolve(contour->ksp[i],BMV,MC));
164:     PetscCall(BVRestoreMat(ctx->Y,&MC));
165:   }
166:   PetscCall(MatDestroy(&BMV));
167:   PetscCall(BVRestoreMat(V,&MV));
168:   PetscFunctionReturn(PETSC_SUCCESS);
169: }

171: static PetscErrorCode NEPSetUp_CISS(NEP nep)
172: {
173:   NEP_CISS         *ctx = (NEP_CISS*)nep->data;
174:   SlepcContourData contour;
175:   PetscInt         nwork;
176:   PetscBool        istrivial,isellipse,flg;
177:   NEP_CISS_PROJECT dsctxf;
178:   PetscObjectId    id;
179:   PetscObjectState state;
180:   Vec              v0;

182:   PetscFunctionBegin;
183:   if (nep->ncv==PETSC_DETERMINE) nep->ncv = ctx->L_max*ctx->M;
184:   else {
185:     ctx->L_max = nep->ncv/ctx->M;
186:     if (!ctx->L_max) {
187:       ctx->L_max = 1;
188:       nep->ncv = ctx->L_max*ctx->M;
189:     }
190:   }
191:   ctx->L = PetscMin(ctx->L,ctx->L_max);
192:   if (nep->max_it==PETSC_DETERMINE) nep->max_it = 5;
193:   if (nep->mpd==PETSC_DETERMINE) nep->mpd = nep->ncv;
194:   if (!nep->which) nep->which = NEP_ALL;
195:   PetscCheck(nep->which==NEP_ALL,PetscObjectComm((PetscObject)nep),PETSC_ERR_SUP,"This solver supports only computing all eigenvalues");
196:   NEPCheckUnsupported(nep,NEP_FEATURE_STOPPING | NEP_FEATURE_TWOSIDED);

198:   /* check region */
199:   PetscCall(RGIsTrivial(nep->rg,&istrivial));
200:   PetscCheck(!istrivial,PetscObjectComm((PetscObject)nep),PETSC_ERR_SUP,"CISS requires a nontrivial region, e.g. -rg_type ellipse ...");
201:   PetscCall(RGGetComplement(nep->rg,&flg));
202:   PetscCheck(!flg,PetscObjectComm((PetscObject)nep),PETSC_ERR_SUP,"A region with complement flag set is not allowed");
203:   PetscCall(PetscObjectTypeCompare((PetscObject)nep->rg,RGELLIPSE,&isellipse));
204:   PetscCheck(isellipse,PetscObjectComm((PetscObject)nep),PETSC_ERR_SUP,"Currently only implemented for elliptic regions");

206:   /* if the region has changed, then reset contour data */
207:   PetscCall(PetscObjectGetId((PetscObject)nep->rg,&id));
208:   PetscCall(PetscObjectStateGet((PetscObject)nep->rg,&state));
209:   if (ctx->rgid && (id != ctx->rgid || state != ctx->rgstate)) {
210:     PetscCall(SlepcContourDataDestroy(&ctx->contour));
211:     PetscCall(PetscInfo(nep,"Resetting the contour data structure due to a change of region\n"));
212:     ctx->rgid = id; ctx->rgstate = state;
213:   }

215:   /* create contour data structure */
216:   if (!ctx->contour) {
217:     PetscCall(RGCanUseConjugates(nep->rg,ctx->isreal,&ctx->useconj));
218:     PetscCall(SlepcContourDataCreate(ctx->useconj?ctx->N/2:ctx->N,ctx->npart,(PetscObject)nep,&ctx->contour));
219:   }

221:   PetscCall(NEPAllocateSolution(nep,0));
222:   if (ctx->weight) PetscCall(PetscFree4(ctx->weight,ctx->omega,ctx->pp,ctx->sigma));
223:   PetscCall(PetscMalloc4(ctx->N,&ctx->weight,ctx->N,&ctx->omega,ctx->N,&ctx->pp,ctx->L_max*ctx->M,&ctx->sigma));

225:   /* allocate basis vectors */
226:   PetscCall(BVDestroy(&ctx->S));
227:   PetscCall(BVDuplicateResize(nep->V,ctx->L*ctx->M,&ctx->S));
228:   PetscCall(BVDestroy(&ctx->V));
229:   PetscCall(BVDuplicateResize(nep->V,ctx->L,&ctx->V));

231:   contour = ctx->contour;
232:   if (contour->subcomm && contour->subcomm->n != 1 && nep->fui==NEP_USER_INTERFACE_CALLBACK) {
233:     PetscCall(NEPComputeFunction(nep,0,nep->function,nep->function_pre));
234:     PetscCall(SlepcContourRedundantMat(contour,1,&nep->function,(nep->function!=nep->function_pre)?&nep->function_pre:NULL));
235:   } else PetscCall(SlepcContourRedundantMat(contour,nep->nt,nep->A,nep->P));
236:   if (contour->pA) {
237:     if (!ctx->J) PetscCall(MatDuplicate(contour->pA[0],MAT_DO_NOT_COPY_VALUES,&ctx->J));
238:     PetscCall(BVGetColumn(ctx->V,0,&v0));
239:     PetscCall(SlepcContourScatterCreate(contour,v0));
240:     PetscCall(BVRestoreColumn(ctx->V,0,&v0));
241:     PetscCall(BVDestroy(&ctx->pV));
242:     PetscCall(BVCreate(PetscObjectComm((PetscObject)contour->xsub),&ctx->pV));
243:     PetscCall(BVSetSizesFromVec(ctx->pV,contour->xsub,nep->n));
244:     PetscCall(BVSetFromOptions(ctx->pV));
245:     PetscCall(BVResize(ctx->pV,ctx->L,PETSC_FALSE));
246:   }

248:   PetscCall(BVDestroy(&ctx->Y));
249:   if (contour->pA) {
250:     PetscCall(BVCreate(PetscObjectComm((PetscObject)contour->xsub),&ctx->Y));
251:     PetscCall(BVSetSizesFromVec(ctx->Y,contour->xsub,nep->n));
252:     PetscCall(BVSetFromOptions(ctx->Y));
253:     PetscCall(BVResize(ctx->Y,contour->npoints*ctx->L,PETSC_FALSE));
254:   } else PetscCall(BVDuplicateResize(nep->V,contour->npoints*ctx->L,&ctx->Y));

256:   if (ctx->extraction == NEP_CISS_EXTRACTION_RITZ)  {
257:     PetscCall(DSSetMethod(nep->ds,1));
258:     PetscCall(DSNEPSetRG(nep->ds,nep->rg));
259:     if (nep->fui==NEP_USER_INTERFACE_SPLIT) PetscCall(DSNEPSetFN(nep->ds,nep->nt,nep->f));
260:     else {
261:       PetscCall(PetscNew(&dsctxf));
262:       dsctxf->nep = nep;
263:       PetscCall(DSNEPSetComputeMatrixFunction(nep->ds,NEPContourDSComputeMatrix,dsctxf,PetscCtxDestroyDefault));
264:     }
265:   }
266:   PetscCall(DSAllocate(nep->ds,nep->ncv));
267:   nwork = (nep->fui==NEP_USER_INTERFACE_SPLIT)? 2: 1;
268:   PetscCall(NEPSetWorkVecs(nep,nwork));
269:   PetscFunctionReturn(PETSC_SUCCESS);
270: }

272: static PetscErrorCode NEPSolve_CISS(NEP nep)
273: {
274:   NEP_CISS         *ctx = (NEP_CISS*)nep->data;
275:   SlepcContourData contour = ctx->contour;
276:   Mat              X,M,E,T,P,J;
277:   BV               V;
278:   PetscInt         i,j,ld,L_add=0,nv=0,L_base=ctx->L,inner,*inside;
279:   PetscScalar      *Mu,*H0,*H1,*rr,*temp,center;
280:   PetscReal        error,max_error,radius,rgscale,est_eig,eta;
281:   PetscBool        isellipse,*fl1;
282:   Vec              si;
283:   SlepcSC          sc;
284:   PetscRandom      rand;
285:   NEP_CISS_PROJECT dsctxf;

287:   PetscFunctionBegin;
288:   PetscCall(DSGetSlepcSC(nep->ds,&sc));
289:   sc->comparison    = SlepcCompareLargestMagnitude;
290:   sc->comparisonctx = NULL;
291:   sc->map           = NULL;
292:   sc->mapobj        = NULL;
293:   PetscCall(DSGetLeadingDimension(nep->ds,&ld));
294:   PetscCall(RGComputeQuadrature(nep->rg,RG_QUADRULE_TRAPEZOIDAL,ctx->N,ctx->omega,ctx->pp,ctx->weight));
295:   if (contour->pA) {
296:     T = contour->pA[0];
297:     P = ((nep->fui==NEP_USER_INTERFACE_SPLIT && nep->P) || (nep->fui==NEP_USER_INTERFACE_CALLBACK && contour->pP))? contour->pP[0]: T;
298:   } else {
299:     T = nep->function;
300:     P = nep->function_pre? nep->function_pre: nep->function;
301:   }
302:   PetscCall(NEPCISSSetUp(nep,T,P));
303:   PetscCall(BVSetActiveColumns(ctx->V,0,ctx->L));
304:   PetscCall(BVSetRandomSign(ctx->V));
305:   PetscCall(BVGetRandomContext(ctx->V,&rand));
306:   if (contour->pA) {
307:     J = ctx->J;
308:     V = ctx->pV;
309:     PetscCall(BVScatter(ctx->V,ctx->pV,contour->scatterin,contour->xdup));
310:   } else {
311:     J = nep->jacobian;
312:     V = ctx->V;
313:   }
314:   PetscCall(NEPCISSSolve(nep,J,V,0,ctx->L));
315:   PetscCall(PetscObjectTypeCompare((PetscObject)nep->rg,RGELLIPSE,&isellipse));
316:   if (isellipse) {
317:     PetscCall(BVTraceQuadrature(ctx->Y,ctx->V,ctx->L,ctx->L,ctx->weight,contour->scatterin,contour->subcomm,contour->npoints,ctx->useconj,&est_eig));
318:     PetscCall(PetscInfo(nep,"Estimated eigenvalue count: %f\n",(double)est_eig));
319:     eta = PetscPowReal(10.0,-PetscLog10Real(nep->tol)/ctx->N);
320:     L_add = PetscMax(0,(PetscInt)PetscCeilReal((est_eig*eta)/ctx->M)-ctx->L);
321:     if (L_add>ctx->L_max-ctx->L) {
322:       PetscCall(PetscInfo(nep,"Number of eigenvalues inside the contour path may be too large\n"));
323:       L_add = ctx->L_max-ctx->L;
324:     }
325:   }
326:   /* Updates L after estimate the number of eigenvalue */
327:   if (L_add>0) {
328:     PetscCall(PetscInfo(nep,"Changing L %" PetscInt_FMT " -> %" PetscInt_FMT " by Estimate #Eig\n",ctx->L,ctx->L+L_add));
329:     PetscCall(BVCISSResizeBases(ctx->S,contour->pA?ctx->pV:ctx->V,ctx->Y,ctx->L,ctx->L+L_add,ctx->M,contour->npoints));
330:     PetscCall(BVSetActiveColumns(ctx->V,ctx->L,ctx->L+L_add));
331:     PetscCall(BVSetRandomSign(ctx->V));
332:     if (contour->pA) PetscCall(BVScatter(ctx->V,ctx->pV,contour->scatterin,contour->xdup));
333:     ctx->L += L_add;
334:     PetscCall(NEPCISSSolve(nep,J,V,ctx->L-L_add,ctx->L));
335:   }

337:   PetscCall(PetscMalloc2(ctx->L*ctx->L*ctx->M*2,&Mu,ctx->L*ctx->M*ctx->L*ctx->M,&H0));
338:   for (i=0;i<ctx->refine_blocksize;i++) {
339:     PetscCall(BVDotQuadrature(ctx->Y,V,Mu,ctx->M,ctx->L,ctx->L,ctx->weight,ctx->pp,contour->subcomm,contour->npoints,ctx->useconj));
340:     PetscCall(CISS_BlockHankel(Mu,0,ctx->L,ctx->M,H0));
341:     PetscCall(PetscLogEventBegin(NEP_CISS_SVD,nep,0,0,0));
342:     PetscCall(SlepcCISS_BH_SVD(H0,ctx->L*ctx->M,ctx->delta,ctx->sigma,&nv));
343:     PetscCall(PetscLogEventEnd(NEP_CISS_SVD,nep,0,0,0));
344:     if (ctx->sigma[0]<=ctx->delta || nv < ctx->L*ctx->M || ctx->L == ctx->L_max) break;
345:     L_add = L_base;
346:     if (ctx->L+L_add>ctx->L_max) L_add = ctx->L_max-ctx->L;
347:     PetscCall(PetscInfo(nep,"Changing L %" PetscInt_FMT " -> %" PetscInt_FMT " by SVD(H0)\n",ctx->L,ctx->L+L_add));
348:     PetscCall(BVCISSResizeBases(ctx->S,contour->pA?ctx->pV:ctx->V,ctx->Y,ctx->L,ctx->L+L_add,ctx->M,contour->npoints));
349:     PetscCall(BVSetActiveColumns(ctx->V,ctx->L,ctx->L+L_add));
350:     PetscCall(BVSetRandomSign(ctx->V));
351:     if (contour->pA) PetscCall(BVScatter(ctx->V,ctx->pV,contour->scatterin,contour->xdup));
352:     ctx->L += L_add;
353:     PetscCall(NEPCISSSolve(nep,J,V,ctx->L-L_add,ctx->L));
354:     if (L_add) {
355:       PetscCall(PetscFree2(Mu,H0));
356:       PetscCall(PetscMalloc2(ctx->L*ctx->L*ctx->M*2,&Mu,ctx->L*ctx->M*ctx->L*ctx->M,&H0));
357:     }
358:   }

360:   PetscCall(RGGetScale(nep->rg,&rgscale));
361:   PetscCall(RGEllipseGetParameters(nep->rg,&center,&radius,NULL));

363:   if (ctx->extraction == NEP_CISS_EXTRACTION_HANKEL) PetscCall(PetscMalloc1(ctx->L*ctx->M*ctx->L*ctx->M,&H1));

365:   while (nep->reason == NEP_CONVERGED_ITERATING) {
366:     nep->its++;
367:     for (inner=0;inner<=ctx->refine_inner;inner++) {
368:       if (ctx->extraction == NEP_CISS_EXTRACTION_HANKEL) {
369:         PetscCall(BVDotQuadrature(ctx->Y,V,Mu,ctx->M,ctx->L,ctx->L,ctx->weight,ctx->pp,contour->subcomm,contour->npoints,ctx->useconj));
370:         PetscCall(CISS_BlockHankel(Mu,0,ctx->L,ctx->M,H0));
371:         PetscCall(PetscLogEventBegin(NEP_CISS_SVD,nep,0,0,0));
372:         PetscCall(SlepcCISS_BH_SVD(H0,ctx->L*ctx->M,ctx->delta,ctx->sigma,&nv));
373:         PetscCall(PetscLogEventEnd(NEP_CISS_SVD,nep,0,0,0));
374:       } else {
375:         PetscCall(BVSumQuadrature(ctx->S,ctx->Y,ctx->M,ctx->L,ctx->L,ctx->weight,ctx->pp,contour->scatterin,contour->subcomm,contour->npoints,ctx->useconj));
376:         /* compute SVD of S */
377:         PetscCall(BVSVDAndRank(ctx->S,ctx->M,ctx->L,ctx->delta,(ctx->extraction==NEP_CISS_EXTRACTION_CAA)?BV_SVD_METHOD_QR_CAA:BV_SVD_METHOD_QR,H0,ctx->sigma,&nv));
378:       }
379:       PetscCall(PetscInfo(nep,"Estimated rank: nv = %" PetscInt_FMT "\n",nv));
380:       if (ctx->sigma[0]>ctx->delta && nv==ctx->L*ctx->M && inner!=ctx->refine_inner) {
381:         PetscCall(BVSumQuadrature(ctx->S,ctx->Y,ctx->M,ctx->L,ctx->L,ctx->weight,ctx->pp,contour->scatterin,contour->subcomm,contour->npoints,ctx->useconj));
382:         PetscCall(BVSetActiveColumns(ctx->S,0,ctx->L));
383:         PetscCall(BVSetActiveColumns(ctx->V,0,ctx->L));
384:         PetscCall(BVCopy(ctx->S,ctx->V));
385:         if (contour->pA) PetscCall(BVScatter(ctx->V,ctx->pV,contour->scatterin,contour->xdup));
386:         PetscCall(NEPCISSSolve(nep,J,V,0,ctx->L));
387:       } else break;
388:     }
389:     nep->nconv = 0;
390:     if (nv == 0) { nep->reason = NEP_CONVERGED_TOL; break; }
391:     else {
392:       /* Extracting eigenpairs */
393:       PetscCall(DSSetDimensions(nep->ds,nv,0,0));
394:       PetscCall(DSSetState(nep->ds,DS_STATE_RAW));
395:       if (ctx->extraction == NEP_CISS_EXTRACTION_HANKEL) {
396:         PetscCall(CISS_BlockHankel(Mu,0,ctx->L,ctx->M,H0));
397:         PetscCall(CISS_BlockHankel(Mu,1,ctx->L,ctx->M,H1));
398:         PetscCall(DSGetArray(nep->ds,DS_MAT_A,&temp));
399:         for (j=0;j<nv;j++)
400:           for (i=0;i<nv;i++)
401:             temp[i+j*ld] = H1[i+j*ctx->L*ctx->M];
402:         PetscCall(DSRestoreArray(nep->ds,DS_MAT_A,&temp));
403:         PetscCall(DSGetArray(nep->ds,DS_MAT_B,&temp));
404:         for (j=0;j<nv;j++)
405:           for (i=0;i<nv;i++)
406:             temp[i+j*ld] = H0[i+j*ctx->L*ctx->M];
407:         PetscCall(DSRestoreArray(nep->ds,DS_MAT_B,&temp));
408:       } else if (ctx->extraction == NEP_CISS_EXTRACTION_CAA) {
409:         PetscCall(BVSetActiveColumns(ctx->S,0,nv));
410:         PetscCall(DSGetArray(nep->ds,DS_MAT_A,&temp));
411:         for (i=0;i<nv;i++) PetscCall(PetscArraycpy(temp+i*ld,H0+i*nv,nv));
412:         PetscCall(DSRestoreArray(nep->ds,DS_MAT_A,&temp));
413:       } else {
414:         PetscCall(BVSetActiveColumns(ctx->S,0,nv));
415:         if (nep->fui==NEP_USER_INTERFACE_SPLIT) {
416:           for (i=0;i<nep->nt;i++) {
417:             PetscCall(DSGetMat(nep->ds,DSMatExtra[i],&E));
418:             PetscCall(BVMatProject(ctx->S,nep->A[i],ctx->S,E));
419:             PetscCall(DSRestoreMat(nep->ds,DSMatExtra[i],&E));
420:           }
421:         } else {
422:           PetscCall(DSNEPGetComputeMatrixFunction(nep->ds,NULL,(PetscCtxRt)&dsctxf,NULL));
423:           dsctxf->Q = ctx->S;
424:         }
425:       }
426:       PetscCall(DSSolve(nep->ds,nep->eigr,nep->eigi));
427:       PetscCall(DSSynchronize(nep->ds,nep->eigr,nep->eigi));
428:       PetscCall(DSGetDimensions(nep->ds,NULL,NULL,NULL,&nv));
429:       if (ctx->extraction == NEP_CISS_EXTRACTION_CAA || ctx->extraction == NEP_CISS_EXTRACTION_HANKEL) {
430:         for (i=0;i<nv;i++) {
431:           nep->eigr[i] = (nep->eigr[i]*radius+center)*rgscale;
432:         }
433:       }
434:       PetscCall(PetscMalloc3(nv,&fl1,nv,&inside,nv,&rr));
435:       PetscCall(DSVectors(nep->ds,DS_MAT_X,NULL,NULL));
436:       PetscCall(DSGetMat(nep->ds,DS_MAT_X,&X));
437:       PetscCall(SlepcCISS_isGhost(X,nv,ctx->sigma,ctx->spurious_threshold,fl1));
438:       PetscCall(DSRestoreMat(nep->ds,DS_MAT_X,&X));
439:       PetscCall(RGCheckInside(nep->rg,nv,nep->eigr,nep->eigi,inside));
440:       for (i=0;i<nv;i++) {
441:         if (fl1[i] && inside[i]>=0) {
442:           rr[i] = 1.0;
443:           nep->nconv++;
444:         } else rr[i] = 0.0;
445:       }
446:       PetscCall(DSSort(nep->ds,nep->eigr,nep->eigi,rr,NULL,&nep->nconv));
447:       PetscCall(DSSynchronize(nep->ds,nep->eigr,nep->eigi));
448:       if (ctx->extraction == NEP_CISS_EXTRACTION_CAA || ctx->extraction == NEP_CISS_EXTRACTION_HANKEL) {
449:         for (i=0;i<nv;i++) nep->eigr[i] = (nep->eigr[i]*radius+center)*rgscale;
450:       }
451:       PetscCall(PetscFree3(fl1,inside,rr));
452:       PetscCall(BVSetActiveColumns(nep->V,0,nv));
453:       PetscCall(DSVectors(nep->ds,DS_MAT_X,NULL,NULL));
454:       if (ctx->extraction == NEP_CISS_EXTRACTION_HANKEL) {
455:         PetscCall(BVSumQuadrature(ctx->S,ctx->Y,ctx->M,ctx->L,ctx->L,ctx->weight,ctx->pp,contour->scatterin,contour->subcomm,contour->npoints,ctx->useconj));
456:         PetscCall(BVSetActiveColumns(ctx->S,0,nv));
457:         PetscCall(BVCopy(ctx->S,nep->V));
458:         PetscCall(DSGetMat(nep->ds,DS_MAT_X,&X));
459:         PetscCall(BVMultInPlace(ctx->S,X,0,nep->nconv));
460:         PetscCall(BVMultInPlace(nep->V,X,0,nep->nconv));
461:         PetscCall(DSRestoreMat(nep->ds,DS_MAT_X,&X));
462:       } else {
463:         PetscCall(DSGetMat(nep->ds,DS_MAT_X,&X));
464:         PetscCall(BVMultInPlace(ctx->S,X,0,nep->nconv));
465:         PetscCall(DSRestoreMat(nep->ds,DS_MAT_X,&X));
466:         PetscCall(BVSetActiveColumns(ctx->S,0,nep->nconv));
467:         PetscCall(BVCopy(ctx->S,nep->V));
468:       }
469:       max_error = 0.0;
470:       for (i=0;i<nep->nconv;i++) {
471:         PetscCall(BVGetColumn(nep->V,i,&si));
472:         PetscCall(VecNormalize(si,NULL));
473:         PetscCall(NEPComputeResidualNorm_Private(nep,PETSC_FALSE,nep->eigr[i],si,nep->work,&error));
474:         PetscCall((*nep->converged)(nep,nep->eigr[i],0,error,&error,nep->convergedctx));
475:         PetscCall(BVRestoreColumn(nep->V,i,&si));
476:         max_error = PetscMax(max_error,error);
477:       }
478:       if (max_error <= nep->tol) nep->reason = NEP_CONVERGED_TOL;
479:       else if (nep->its > nep->max_it) nep->reason = NEP_DIVERGED_ITS;
480:       else {
481:         if (nep->nconv > ctx->L) nv = nep->nconv;
482:         else if (ctx->L > nv) nv = ctx->L;
483:         nv = PetscMin(nv,ctx->L*ctx->M);
484:         PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,nv,ctx->L,NULL,&M));
485:         PetscCall(MatSetRandom(M,rand));
486:         PetscCall(BVSetActiveColumns(ctx->S,0,nv));
487:         PetscCall(BVMultInPlace(ctx->S,M,0,ctx->L));
488:         PetscCall(MatDestroy(&M));
489:         PetscCall(BVSetActiveColumns(ctx->S,0,ctx->L));
490:         PetscCall(BVSetActiveColumns(ctx->V,0,ctx->L));
491:         PetscCall(BVCopy(ctx->S,ctx->V));
492:         if (contour->pA) PetscCall(BVScatter(ctx->V,ctx->pV,contour->scatterin,contour->xdup));
493:         PetscCall(NEPCISSSolve(nep,J,V,0,ctx->L));
494:       }
495:     }
496:   }
497:   PetscCall(PetscFree2(Mu,H0));
498:   if (ctx->extraction == NEP_CISS_EXTRACTION_HANKEL) PetscCall(PetscFree(H1));
499:   PetscFunctionReturn(PETSC_SUCCESS);
500: }

502: static PetscErrorCode NEPCISSSetSizes_CISS(NEP nep,PetscInt ip,PetscInt bs,PetscInt ms,PetscInt npart,PetscInt bsmax,PetscBool realmats)
503: {
504:   NEP_CISS       *ctx = (NEP_CISS*)nep->data;
505:   PetscInt       oN,oL,oM,oLmax,onpart;
506:   PetscMPIInt    size;

508:   PetscFunctionBegin;
509:   oN = ctx->N;
510:   if (ip == PETSC_DETERMINE) {
511:     if (ctx->N!=32) { ctx->N =32; ctx->M = ctx->N/4; }
512:   } else if (ip != PETSC_CURRENT) {
513:     PetscCheck(ip>0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"The ip argument must be > 0");
514:     PetscCheck(ip%2==0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"The ip argument must be an even number");
515:     if (ctx->N!=ip) { ctx->N = ip; ctx->M = ctx->N/4; }
516:   }
517:   oL = ctx->L;
518:   if (bs == PETSC_DETERMINE) {
519:     ctx->L = 16;
520:   } else if (bs != PETSC_CURRENT) {
521:     PetscCheck(bs>0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"The bs argument must be > 0");
522:     ctx->L = bs;
523:   }
524:   oM = ctx->M;
525:   if (ms == PETSC_DETERMINE) {
526:     ctx->M = ctx->N/4;
527:   } else if (ms != PETSC_CURRENT) {
528:     PetscCheck(ms>0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"The ms argument must be > 0");
529:     PetscCheck(ms<=ctx->N,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"The ms argument must be less than or equal to the number of integration points");
530:     ctx->M = ms;
531:   }
532:   onpart = ctx->npart;
533:   if (npart == PETSC_DETERMINE) {
534:     ctx->npart = 1;
535:   } else if (npart != PETSC_CURRENT) {
536:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)nep),&size));
537:     PetscCheck(npart>0 && npart<=size,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of npart");
538:     ctx->npart = npart;
539:   }
540:   oLmax = ctx->L_max;
541:   if (bsmax == PETSC_DETERMINE) {
542:     ctx->L_max = 64;
543:   } else if (bsmax != PETSC_CURRENT) {
544:     PetscCheck(bsmax>0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"The bsmax argument must be > 0");
545:     ctx->L_max = PetscMax(bsmax,ctx->L);
546:   }
547:   if (onpart != ctx->npart || oN != ctx->N || realmats != ctx->isreal) {
548:     PetscCall(SlepcContourDataDestroy(&ctx->contour));
549:     PetscCall(PetscInfo(nep,"Resetting the contour data structure due to a change of parameters\n"));
550:     nep->state = NEP_STATE_INITIAL;
551:   }
552:   ctx->isreal = realmats;
553:   if (oL != ctx->L || oM != ctx->M || oLmax != ctx->L_max) nep->state = NEP_STATE_INITIAL;
554:   PetscFunctionReturn(PETSC_SUCCESS);
555: }

557: /*@
558:    NEPCISSSetSizes - Sets the values of various size parameters in the CISS solver.

560:    Logically Collective

562:    Input Parameters:
563: +  nep      - the nonlinear eigensolver context
564: .  ip       - number of integration points
565: .  bs       - block size
566: .  ms       - moment size
567: .  npart    - number of partitions when splitting the communicator
568: .  bsmax    - max block size
569: -  realmats - $T(z)$ is real for real $z$

571:    Options Database Keys:
572: +  -nep_ciss_integration_points ip - sets the number of integration points
573: .  -nep_ciss_blocksize bs          - sets the block size
574: .  -nep_ciss_moments ms            - sets the moment size
575: .  -nep_ciss_partitions npart      - sets the number of partitions
576: .  -nep_ciss_maxblocksize bsmax    - sets the maximum block size
577: -  -nep_ciss_realmats (true|false) - $T(z)$ is real for real $z$

579:    Notes:
580:    For all integer arguments, you can use `PETSC_CURRENT` to keep the current value, and
581:    `PETSC_DETERMINE` to set them to a default value.

583:    The default number of partitions is 1. This means the internal `KSP` object is shared
584:    among all processes of the `NEP` communicator. Otherwise, the communicator is split
585:    into `npart` communicators, so that `npart` `KSP` solves proceed simultaneously.

587:    The `realmats` flag can be set to `PETSC_TRUE` when $T(\cdot)$ is guaranteed to be real
588:    when the argument is a real value, for example, when all matrices in
589:    the split form are real. When set to `PETSC_TRUE`, the solver avoids some computations.

591:    For a detailed description of the parameters see {cite:p}`Mae16`.

593:    Level: advanced

595: .seealso: [](ch:nep), `NEPCISS`, `NEPCISSGetSizes()`
596: @*/
597: PetscErrorCode NEPCISSSetSizes(NEP nep,PetscInt ip,PetscInt bs,PetscInt ms,PetscInt npart,PetscInt bsmax,PetscBool realmats)
598: {
599:   PetscFunctionBegin;
607:   PetscTryMethod(nep,"NEPCISSSetSizes_C",(NEP,PetscInt,PetscInt,PetscInt,PetscInt,PetscInt,PetscBool),(nep,ip,bs,ms,npart,bsmax,realmats));
608:   PetscFunctionReturn(PETSC_SUCCESS);
609: }

611: static PetscErrorCode NEPCISSGetSizes_CISS(NEP nep,PetscInt *ip,PetscInt *bs,PetscInt *ms,PetscInt *npart,PetscInt *bsmax,PetscBool *realmats)
612: {
613:   NEP_CISS *ctx = (NEP_CISS*)nep->data;

615:   PetscFunctionBegin;
616:   if (ip) *ip = ctx->N;
617:   if (bs) *bs = ctx->L;
618:   if (ms) *ms = ctx->M;
619:   if (npart) *npart = ctx->npart;
620:   if (bsmax) *bsmax = ctx->L_max;
621:   if (realmats) *realmats = ctx->isreal;
622:   PetscFunctionReturn(PETSC_SUCCESS);
623: }

625: /*@
626:    NEPCISSGetSizes - Gets the values of various size parameters in the CISS solver.

628:    Not Collective

630:    Input Parameter:
631: .  nep - the nonlinear eigensolver context

633:    Output Parameters:
634: +  ip       - number of integration points
635: .  bs       - block size
636: .  ms       - moment size
637: .  npart    - number of partitions when splitting the communicator
638: .  bsmax    - max block size
639: -  realmats - $T(z)$ is real for real $z$

641:    Level: advanced

643: .seealso: [](ch:nep), `NEPCISS`, `NEPCISSSetSizes()`
644: @*/
645: PetscErrorCode NEPCISSGetSizes(NEP nep,PetscInt *ip,PetscInt *bs,PetscInt *ms,PetscInt *npart,PetscInt *bsmax,PetscBool *realmats)
646: {
647:   PetscFunctionBegin;
649:   PetscUseMethod(nep,"NEPCISSGetSizes_C",(NEP,PetscInt*,PetscInt*,PetscInt*,PetscInt*,PetscInt*,PetscBool*),(nep,ip,bs,ms,npart,bsmax,realmats));
650:   PetscFunctionReturn(PETSC_SUCCESS);
651: }

653: static PetscErrorCode NEPCISSSetThreshold_CISS(NEP nep,PetscReal delta,PetscReal spur)
654: {
655:   NEP_CISS *ctx = (NEP_CISS*)nep->data;

657:   PetscFunctionBegin;
658:   if (delta == (PetscReal)PETSC_DETERMINE) {
659:     ctx->delta = SLEPC_DEFAULT_TOL*1e-4;
660:   } else if (delta != (PetscReal)PETSC_CURRENT) {
661:     PetscCheck(delta>0.0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"The delta argument must be > 0.0");
662:     ctx->delta = delta;
663:   }
664:   if (spur == (PetscReal)PETSC_DETERMINE) {
665:     ctx->spurious_threshold = PetscSqrtReal(SLEPC_DEFAULT_TOL);
666:   } else if (spur != (PetscReal)PETSC_CURRENT) {
667:     PetscCheck(spur>0.0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"The spurious threshold argument must be > 0.0");
668:     ctx->spurious_threshold = spur;
669:   }
670:   PetscFunctionReturn(PETSC_SUCCESS);
671: }

673: /*@
674:    NEPCISSSetThreshold - Sets the values of various threshold parameters in
675:    the CISS solver.

677:    Logically Collective

679:    Input Parameters:
680: +  nep   - the nonlinear eigensolver context
681: .  delta - threshold for numerical rank
682: -  spur  - spurious threshold (to discard spurious eigenpairs)

684:    Options Database Keys:
685: +  -nep_ciss_delta delta             - sets the delta
686: -  -nep_ciss_spurious_threshold spur - sets the spurious threshold

688:    Notes:
689:    `PETSC_CURRENT` can be used to preserve the current value of any of the
690:    arguments, and `PETSC_DETERMINE` to set them to a default value.

692:    For a detailed description of the parameters see {cite:p}`Mae16`.

694:    Level: advanced

696: .seealso: [](ch:nep), `NEPCISS`, `NEPCISSGetThreshold()`
697: @*/
698: PetscErrorCode NEPCISSSetThreshold(NEP nep,PetscReal delta,PetscReal spur)
699: {
700:   PetscFunctionBegin;
704:   PetscTryMethod(nep,"NEPCISSSetThreshold_C",(NEP,PetscReal,PetscReal),(nep,delta,spur));
705:   PetscFunctionReturn(PETSC_SUCCESS);
706: }

708: static PetscErrorCode NEPCISSGetThreshold_CISS(NEP nep,PetscReal *delta,PetscReal *spur)
709: {
710:   NEP_CISS *ctx = (NEP_CISS*)nep->data;

712:   PetscFunctionBegin;
713:   if (delta) *delta = ctx->delta;
714:   if (spur)  *spur = ctx->spurious_threshold;
715:   PetscFunctionReturn(PETSC_SUCCESS);
716: }

718: /*@
719:    NEPCISSGetThreshold - Gets the values of various threshold parameters in
720:    the CISS solver.

722:    Not Collective

724:    Input Parameter:
725: .  nep - the nonlinear eigensolver context

727:    Output Parameters:
728: +  delta - threshold for numerical rank
729: -  spur  - spurious threshold (to discard spurious eigenpairs)

731:    Level: advanced

733: .seealso: [](ch:nep), `NEPCISS`, `NEPCISSSetThreshold()`
734: @*/
735: PetscErrorCode NEPCISSGetThreshold(NEP nep,PetscReal *delta,PetscReal *spur)
736: {
737:   PetscFunctionBegin;
739:   PetscUseMethod(nep,"NEPCISSGetThreshold_C",(NEP,PetscReal*,PetscReal*),(nep,delta,spur));
740:   PetscFunctionReturn(PETSC_SUCCESS);
741: }

743: static PetscErrorCode NEPCISSSetRefinement_CISS(NEP nep,PetscInt inner,PetscInt blsize)
744: {
745:   NEP_CISS *ctx = (NEP_CISS*)nep->data;

747:   PetscFunctionBegin;
748:   if (inner == PETSC_DETERMINE) {
749:     ctx->refine_inner = 0;
750:   } else if (inner != PETSC_CURRENT) {
751:     PetscCheck(inner>=0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"The refine inner argument must be >= 0");
752:     ctx->refine_inner = inner;
753:   }
754:   if (blsize == PETSC_DETERMINE) {
755:     ctx->refine_blocksize = 0;
756:   } else if (blsize != PETSC_CURRENT) {
757:     PetscCheck(blsize>=0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"The refine blocksize argument must be >= 0");
758:     ctx->refine_blocksize = blsize;
759:   }
760:   PetscFunctionReturn(PETSC_SUCCESS);
761: }

763: /*@
764:    NEPCISSSetRefinement - Sets the values of various refinement parameters
765:    in the CISS solver.

767:    Logically Collective

769:    Input Parameters:
770: +  nep    - the nonlinear eigensolver context
771: .  inner  - number of iterative refinement iterations (inner loop)
772: -  blsize - number of iterative refinement iterations (blocksize loop)

774:    Options Database Keys:
775: +  -nep_ciss_refine_inner inner      - sets number of inner iterations
776: -  -nep_ciss_refine_blocksize blsize - sets number of blocksize iterations

778:    Note:
779:    `PETSC_CURRENT` can be used to preserve the current value of any of the
780:    arguments, and `PETSC_DETERMINE` to set them to a default of 0 (no refinement).

782:    Level: advanced

784: .seealso: [](ch:nep), `NEPCISS`, `NEPCISSGetRefinement()`
785: @*/
786: PetscErrorCode NEPCISSSetRefinement(NEP nep,PetscInt inner,PetscInt blsize)
787: {
788:   PetscFunctionBegin;
792:   PetscTryMethod(nep,"NEPCISSSetRefinement_C",(NEP,PetscInt,PetscInt),(nep,inner,blsize));
793:   PetscFunctionReturn(PETSC_SUCCESS);
794: }

796: static PetscErrorCode NEPCISSGetRefinement_CISS(NEP nep,PetscInt *inner,PetscInt *blsize)
797: {
798:   NEP_CISS *ctx = (NEP_CISS*)nep->data;

800:   PetscFunctionBegin;
801:   if (inner)  *inner = ctx->refine_inner;
802:   if (blsize) *blsize = ctx->refine_blocksize;
803:   PetscFunctionReturn(PETSC_SUCCESS);
804: }

806: /*@
807:    NEPCISSGetRefinement - Gets the values of various refinement parameters
808:    in the CISS solver.

810:    Not Collective

812:    Input Parameter:
813: .  nep - the nonlinear eigensolver context

815:    Output Parameters:
816: +  inner  - number of iterative refinement iterations (inner loop)
817: -  blsize - number of iterative refinement iterations (blocksize loop)

819:    Level: advanced

821: .seealso: [](ch:nep), `NEPCISS`, `NEPCISSSetRefinement()`
822: @*/
823: PetscErrorCode NEPCISSGetRefinement(NEP nep, PetscInt *inner, PetscInt *blsize)
824: {
825:   PetscFunctionBegin;
827:   PetscUseMethod(nep,"NEPCISSGetRefinement_C",(NEP,PetscInt*,PetscInt*),(nep,inner,blsize));
828:   PetscFunctionReturn(PETSC_SUCCESS);
829: }

831: static PetscErrorCode NEPCISSSetExtraction_CISS(NEP nep,NEPCISSExtraction extraction)
832: {
833:   NEP_CISS *ctx = (NEP_CISS*)nep->data;

835:   PetscFunctionBegin;
836:   if (ctx->extraction != extraction) {
837:     ctx->extraction = extraction;
838:     nep->state      = NEP_STATE_INITIAL;
839:   }
840:   PetscFunctionReturn(PETSC_SUCCESS);
841: }

843: /*@
844:    NEPCISSSetExtraction - Sets the extraction technique used in the CISS solver.

846:    Logically Collective

848:    Input Parameters:
849: +  nep        - the nonlinear eigensolver context
850: -  extraction - the extraction technique, see `NEPCISSExtraction` for possible values

852:    Options Database Key:
853: .  -nep_ciss_extraction (ritz|hankel|caa) - sets the extraction technique

855:    Notes:
856:    By default, the Rayleigh-Ritz extraction is used (`NEP_CISS_EXTRACTION_RITZ`).

858:    If the `hankel` or the `caa` option is specified (`NEP_CISS_EXTRACTION_HANKEL` or
859:    `NEP_CISS_EXTRACTION_CAA`), then the block Hankel method, or the communication-avoiding
860:    Arnoldi method, respectively, is used for extracting eigenpairs.

862:    Level: advanced

864: .seealso: [](ch:nep), `NEPCISS`, `NEPCISSGetExtraction()`, `NEPCISSExtraction`
865: @*/
866: PetscErrorCode NEPCISSSetExtraction(NEP nep,NEPCISSExtraction extraction)
867: {
868:   PetscFunctionBegin;
871:   PetscTryMethod(nep,"NEPCISSSetExtraction_C",(NEP,NEPCISSExtraction),(nep,extraction));
872:   PetscFunctionReturn(PETSC_SUCCESS);
873: }

875: static PetscErrorCode NEPCISSGetExtraction_CISS(NEP nep,NEPCISSExtraction *extraction)
876: {
877:   NEP_CISS *ctx = (NEP_CISS*)nep->data;

879:   PetscFunctionBegin;
880:   *extraction = ctx->extraction;
881:   PetscFunctionReturn(PETSC_SUCCESS);
882: }

884: /*@
885:    NEPCISSGetExtraction - Gets the extraction technique used in the CISS solver.

887:    Not Collective

889:    Input Parameter:
890: .  nep - the nonlinear eigensolver context

892:    Output Parameter:
893: .  extraction - extraction technique

895:    Level: advanced

897: .seealso: [](ch:nep), `NEPCISS`, `NEPCISSSetExtraction()`, `NEPCISSExtraction`
898: @*/
899: PetscErrorCode NEPCISSGetExtraction(NEP nep,NEPCISSExtraction *extraction)
900: {
901:   PetscFunctionBegin;
903:   PetscAssertPointer(extraction,2);
904:   PetscUseMethod(nep,"NEPCISSGetExtraction_C",(NEP,NEPCISSExtraction*),(nep,extraction));
905:   PetscFunctionReturn(PETSC_SUCCESS);
906: }

908: static PetscErrorCode NEPCISSGetKSPs_CISS(NEP nep,PetscInt *nsolve,KSP **ksp)
909: {
910:   NEP_CISS         *ctx = (NEP_CISS*)nep->data;
911:   SlepcContourData contour;
912:   PetscInt         i;
913:   PC               pc;
914:   MPI_Comm         child;

916:   PetscFunctionBegin;
917:   if (!ctx->contour) {  /* initialize contour data structure first */
918:     PetscCall(RGCanUseConjugates(nep->rg,ctx->isreal,&ctx->useconj));
919:     PetscCall(SlepcContourDataCreate(ctx->useconj?ctx->N/2:ctx->N,ctx->npart,(PetscObject)nep,&ctx->contour));
920:   }
921:   contour = ctx->contour;
922:   if (!contour->ksp) {
923:     PetscCall(PetscMalloc1(contour->npoints,&contour->ksp));
924:     PetscCall(PetscSubcommGetChild(contour->subcomm,&child));
925:     for (i=0;i<contour->npoints;i++) {
926:       PetscCall(KSPCreate(child,&contour->ksp[i]));
927:       PetscCall(PetscObjectIncrementTabLevel((PetscObject)contour->ksp[i],(PetscObject)nep,1));
928:       PetscCall(KSPSetOptionsPrefix(contour->ksp[i],((PetscObject)nep)->prefix));
929:       PetscCall(KSPAppendOptionsPrefix(contour->ksp[i],"nep_ciss_"));
930:       PetscCall(PetscObjectSetOptions((PetscObject)contour->ksp[i],((PetscObject)nep)->options));
931:       PetscCall(KSPSetErrorIfNotConverged(contour->ksp[i],PETSC_TRUE));
932:       PetscCall(KSPSetTolerances(contour->ksp[i],SlepcDefaultTol(nep->tol),PETSC_CURRENT,PETSC_CURRENT,PETSC_CURRENT));
933:       PetscCall(KSPGetPC(contour->ksp[i],&pc));
934:       if ((nep->fui==NEP_USER_INTERFACE_SPLIT && nep->P) || (nep->fui==NEP_USER_INTERFACE_CALLBACK && nep->function_pre!=nep->function)) {
935:         PetscCall(KSPSetType(contour->ksp[i],KSPBCGS));
936:         PetscCall(PCSetType(pc,PCBJACOBI));
937:       } else {
938:         PetscCall(KSPSetType(contour->ksp[i],KSPPREONLY));
939:         PetscCall(PCSetType(pc,PCLU));
940:       }
941:     }
942:   }
943:   if (nsolve) *nsolve = contour->npoints;
944:   if (ksp)    *ksp    = contour->ksp;
945:   PetscFunctionReturn(PETSC_SUCCESS);
946: }

948: /*@C
949:    NEPCISSGetKSPs - Retrieve the array of linear solver objects associated with
950:    the CISS solver.

952:    Collective

954:    Input Parameter:
955: .  nep - the nonlinear eigensolver context

957:    Output Parameters:
958: +  nsolve - number of solver objects
959: -  ksp - array of linear solver object

961:    Notes:
962:    The number of `KSP` solvers is equal to the number of integration points divided by
963:    the number of partitions. This value is halved in the case of real matrices with
964:    a region centered at the real axis.

966:    Level: advanced

968: .seealso: [](ch:nep), `NEPCISS`, `NEPCISSSetSizes()`
969: @*/
970: PetscErrorCode NEPCISSGetKSPs(NEP nep,PetscInt *nsolve,KSP **ksp)
971: {
972:   PetscFunctionBegin;
974:   PetscUseMethod(nep,"NEPCISSGetKSPs_C",(NEP,PetscInt*,KSP**),(nep,nsolve,ksp));
975:   PetscFunctionReturn(PETSC_SUCCESS);
976: }

978: static PetscErrorCode NEPReset_CISS(NEP nep)
979: {
980:   NEP_CISS       *ctx = (NEP_CISS*)nep->data;

982:   PetscFunctionBegin;
983:   PetscCall(BVDestroy(&ctx->S));
984:   PetscCall(BVDestroy(&ctx->V));
985:   PetscCall(BVDestroy(&ctx->Y));
986:   PetscCall(SlepcContourDataReset(ctx->contour));
987:   PetscCall(MatDestroy(&ctx->J));
988:   PetscCall(BVDestroy(&ctx->pV));
989:   PetscFunctionReturn(PETSC_SUCCESS);
990: }

992: static PetscErrorCode NEPSetFromOptions_CISS(NEP nep,PetscOptionItems PetscOptionsObject)
993: {
994:   NEP_CISS          *ctx = (NEP_CISS*)nep->data;
995:   PetscReal         r1,r2;
996:   PetscInt          i,i1,i2,i3,i4,i5,i6,i7;
997:   PetscBool         b1,flg,flg2,flg3,flg4,flg5,flg6;
998:   NEPCISSExtraction extraction;

1000:   PetscFunctionBegin;
1001:   PetscOptionsHeadBegin(PetscOptionsObject,"NEP CISS Options");

1003:     PetscCall(NEPCISSGetSizes(nep,&i1,&i2,&i3,&i4,&i5,&b1));
1004:     PetscCall(PetscOptionsInt("-nep_ciss_integration_points","Number of integration points","NEPCISSSetSizes",i1,&i1,&flg));
1005:     PetscCall(PetscOptionsInt("-nep_ciss_blocksize","Block size","NEPCISSSetSizes",i2,&i2,&flg2));
1006:     PetscCall(PetscOptionsInt("-nep_ciss_moments","Moment size","NEPCISSSetSizes",i3,&i3,&flg3));
1007:     PetscCall(PetscOptionsInt("-nep_ciss_partitions","Number of partitions","NEPCISSSetSizes",i4,&i4,&flg4));
1008:     PetscCall(PetscOptionsInt("-nep_ciss_maxblocksize","Maximum block size","NEPCISSSetSizes",i5,&i5,&flg5));
1009:     PetscCall(PetscOptionsBool("-nep_ciss_realmats","True if T(z) is real for real z","NEPCISSSetSizes",b1,&b1,&flg6));
1010:     if (flg || flg2 || flg3 || flg4 || flg5 || flg6) PetscCall(NEPCISSSetSizes(nep,i1,i2,i3,i4,i5,b1));

1012:     PetscCall(NEPCISSGetThreshold(nep,&r1,&r2));
1013:     PetscCall(PetscOptionsReal("-nep_ciss_delta","Threshold for numerical rank","NEPCISSSetThreshold",r1,&r1,&flg));
1014:     PetscCall(PetscOptionsReal("-nep_ciss_spurious_threshold","Threshold for the spurious eigenpairs","NEPCISSSetThreshold",r2,&r2,&flg2));
1015:     if (flg || flg2) PetscCall(NEPCISSSetThreshold(nep,r1,r2));

1017:     PetscCall(NEPCISSGetRefinement(nep,&i6,&i7));
1018:     PetscCall(PetscOptionsInt("-nep_ciss_refine_inner","Number of inner iterative refinement iterations","NEPCISSSetRefinement",i6,&i6,&flg));
1019:     PetscCall(PetscOptionsInt("-nep_ciss_refine_blocksize","Number of blocksize iterative refinement iterations","NEPCISSSetRefinement",i7,&i7,&flg2));
1020:     if (flg || flg2) PetscCall(NEPCISSSetRefinement(nep,i6,i7));

1022:     PetscCall(PetscOptionsEnum("-nep_ciss_extraction","Extraction technique","NEPCISSSetExtraction",NEPCISSExtractions,(PetscEnum)ctx->extraction,(PetscEnum*)&extraction,&flg));
1023:     if (flg) PetscCall(NEPCISSSetExtraction(nep,extraction));

1025:   PetscOptionsHeadEnd();

1027:   if (!nep->rg) PetscCall(NEPGetRG(nep,&nep->rg));
1028:   PetscCall(RGSetFromOptions(nep->rg)); /* this is necessary here to set useconj */
1029:   if (!ctx->contour || !ctx->contour->ksp) PetscCall(NEPCISSGetKSPs(nep,NULL,NULL));
1030:   PetscAssert(ctx->contour && ctx->contour->ksp,PetscObjectComm((PetscObject)nep),PETSC_ERR_PLIB,"Something went wrong with NEPCISSGetKSPs()");
1031:   for (i=0;i<ctx->contour->npoints;i++) PetscCall(KSPSetFromOptions(ctx->contour->ksp[i]));
1032:   PetscCall(PetscSubcommSetFromOptions(ctx->contour->subcomm));
1033:   PetscFunctionReturn(PETSC_SUCCESS);
1034: }

1036: static PetscErrorCode NEPDestroy_CISS(NEP nep)
1037: {
1038:   NEP_CISS       *ctx = (NEP_CISS*)nep->data;

1040:   PetscFunctionBegin;
1041:   PetscCall(SlepcContourDataDestroy(&ctx->contour));
1042:   PetscCall(PetscFree4(ctx->weight,ctx->omega,ctx->pp,ctx->sigma));
1043:   PetscCall(PetscFree(nep->data));
1044:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSSetSizes_C",NULL));
1045:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSGetSizes_C",NULL));
1046:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSSetThreshold_C",NULL));
1047:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSGetThreshold_C",NULL));
1048:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSSetRefinement_C",NULL));
1049:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSGetRefinement_C",NULL));
1050:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSSetExtraction_C",NULL));
1051:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSGetExtraction_C",NULL));
1052:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSGetKSPs_C",NULL));
1053:   PetscFunctionReturn(PETSC_SUCCESS);
1054: }

1056: static PetscErrorCode NEPView_CISS(NEP nep,PetscViewer viewer)
1057: {
1058:   NEP_CISS       *ctx = (NEP_CISS*)nep->data;
1059:   PetscBool      isascii;
1060:   PetscViewer    sviewer;

1062:   PetscFunctionBegin;
1063:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii));
1064:   if (isascii) {
1065:     PetscCall(PetscViewerASCIIPrintf(viewer,"  sizes { integration points: %" PetscInt_FMT ", block size: %" PetscInt_FMT ", moment size: %" PetscInt_FMT ", partitions: %" PetscInt_FMT ", maximum block size: %" PetscInt_FMT " }\n",ctx->N,ctx->L,ctx->M,ctx->npart,ctx->L_max));
1066:     if (ctx->isreal) PetscCall(PetscViewerASCIIPrintf(viewer,"  exploiting symmetry of integration points\n"));
1067:     PetscCall(PetscViewerASCIIPrintf(viewer,"  threshold { delta: %g, spurious threshold: %g }\n",(double)ctx->delta,(double)ctx->spurious_threshold));
1068:     PetscCall(PetscViewerASCIIPrintf(viewer,"  iterative refinement  { inner: %" PetscInt_FMT ", blocksize: %" PetscInt_FMT " }\n",ctx->refine_inner, ctx->refine_blocksize));
1069:     PetscCall(PetscViewerASCIIPrintf(viewer,"  extraction: %s\n",NEPCISSExtractions[ctx->extraction]));
1070:     if (!ctx->contour || !ctx->contour->ksp) PetscCall(NEPCISSGetKSPs(nep,NULL,NULL));
1071:     PetscAssert(ctx->contour && ctx->contour->ksp,PetscObjectComm((PetscObject)nep),PETSC_ERR_PLIB,"Something went wrong with NEPCISSGetKSPs()");
1072:     PetscCall(PetscViewerASCIIPushTab(viewer));
1073:     if (ctx->npart>1 && ctx->contour->subcomm) {
1074:       PetscCall(PetscViewerGetSubViewer(viewer,ctx->contour->subcomm->child,&sviewer));
1075:       if (!ctx->contour->subcomm->color) PetscCall(KSPView(ctx->contour->ksp[0],sviewer));
1076:       PetscCall(PetscViewerFlush(sviewer));
1077:       PetscCall(PetscViewerRestoreSubViewer(viewer,ctx->contour->subcomm->child,&sviewer));
1078:       /* extra call needed because of the two calls to PetscViewerASCIIPushSynchronized() in PetscViewerGetSubViewer() */
1079:       PetscCall(PetscViewerASCIIPopSynchronized(viewer));
1080:     } else PetscCall(KSPView(ctx->contour->ksp[0],viewer));
1081:     PetscCall(PetscViewerASCIIPopTab(viewer));
1082:   }
1083:   PetscFunctionReturn(PETSC_SUCCESS);
1084: }

1086: static PetscErrorCode NEPSetDSType_CISS(NEP nep)
1087: {
1088:   NEP_CISS       *ctx = (NEP_CISS*)nep->data;

1090:   PetscFunctionBegin;
1091:   switch (ctx->extraction) {
1092:     case NEP_CISS_EXTRACTION_RITZ:   PetscCall(DSSetType(nep->ds,DSNEP)); break;
1093:     case NEP_CISS_EXTRACTION_HANKEL: PetscCall(DSSetType(nep->ds,DSGNHEP)); break;
1094:     case NEP_CISS_EXTRACTION_CAA:    PetscCall(DSSetType(nep->ds,DSNHEP)); break;
1095:   }
1096:   PetscFunctionReturn(PETSC_SUCCESS);
1097: }

1099: /*MC
1100:    NEPCISS - NEPCISS = "ciss" - A contour integral eigensolver based on the
1101:    Sakurai-Sugiura scheme.

1103:    Notes:
1104:    This solver is based on the numerical contour integration idea
1105:    proposed initially for linear problems by {cite:t}`Sak03`. In nonlinear
1106:    eigenproblems, a Rayleigh-Ritz projection is done, resulting in
1107:    a small dense nonlinear eigenproblem {cite:p}`Asa09,Yok13`.

1109:    Contour integral methods are able to compute all eigenvalues
1110:    lying inside a region of the complex plane. Use `NEPGetRG()` to
1111:    specify the region. However, the computational cost is usually high
1112:    because multiple linear systems must be solved. Use `NEPCISSGetKSPs()`
1113:    to configure the `KSP` objects for this.

1115:    Details of the implementation in SLEPc can be found in {cite:p}`Mae16`.

1117:    Level: beginner

1119: .seealso: [](ch:nep), `NEP`, `NEPType`, `NEPSetType()`, `NEPGetRG()`
1120: M*/
1121: SLEPC_EXTERN PetscErrorCode NEPCreate_CISS(NEP nep)
1122: {
1123:   NEP_CISS       *ctx = (NEP_CISS*)nep->data;

1125:   PetscFunctionBegin;
1126:   PetscCall(PetscNew(&ctx));
1127:   nep->data = ctx;
1128:   /* set default values of parameters */
1129:   ctx->N                  = 32;
1130:   ctx->L                  = 16;
1131:   ctx->M                  = ctx->N/4;
1132:   ctx->delta              = SLEPC_DEFAULT_TOL*1e-4;
1133:   ctx->L_max              = 64;
1134:   ctx->spurious_threshold = PetscSqrtReal(SLEPC_DEFAULT_TOL);
1135:   ctx->isreal             = PETSC_FALSE;
1136:   ctx->npart              = 1;

1138:   nep->useds = PETSC_TRUE;

1140:   nep->ops->solve          = NEPSolve_CISS;
1141:   nep->ops->setup          = NEPSetUp_CISS;
1142:   nep->ops->setfromoptions = NEPSetFromOptions_CISS;
1143:   nep->ops->reset          = NEPReset_CISS;
1144:   nep->ops->destroy        = NEPDestroy_CISS;
1145:   nep->ops->view           = NEPView_CISS;
1146:   nep->ops->setdstype      = NEPSetDSType_CISS;

1148:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSSetSizes_C",NEPCISSSetSizes_CISS));
1149:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSGetSizes_C",NEPCISSGetSizes_CISS));
1150:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSSetThreshold_C",NEPCISSSetThreshold_CISS));
1151:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSGetThreshold_C",NEPCISSGetThreshold_CISS));
1152:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSSetRefinement_C",NEPCISSSetRefinement_CISS));
1153:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSGetRefinement_C",NEPCISSGetRefinement_CISS));
1154:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSSetExtraction_C",NEPCISSSetExtraction_CISS));
1155:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSGetExtraction_C",NEPCISSGetExtraction_CISS));
1156:   PetscCall(PetscObjectComposeFunction((PetscObject)nep,"NEPCISSGetKSPs_C",NEPCISSGetKSPs_CISS));
1157:   PetscFunctionReturn(PETSC_SUCCESS);
1158: }