Actual source code: cyclic.c

slepc-3.7.1 2016-05-27
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  1: /*

  3:    SLEPc singular value solver: "cyclic"

  5:    Method: Uses a Hermitian eigensolver for H(A) = [ 0  A ; A^T 0 ]

  7:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  8:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  9:    Copyright (c) 2002-2016, Universitat Politecnica de Valencia, Spain

 11:    This file is part of SLEPc.

 13:    SLEPc is free software: you can redistribute it and/or modify it under  the
 14:    terms of version 3 of the GNU Lesser General Public License as published by
 15:    the Free Software Foundation.

 17:    SLEPc  is  distributed in the hope that it will be useful, but WITHOUT  ANY
 18:    WARRANTY;  without even the implied warranty of MERCHANTABILITY or  FITNESS
 19:    FOR  A  PARTICULAR PURPOSE. See the GNU Lesser General Public  License  for
 20:    more details.

 22:    You  should have received a copy of the GNU Lesser General  Public  License
 23:    along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
 24:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 25: */

 27: #include <slepc/private/svdimpl.h>                /*I "slepcsvd.h" I*/
 28: #include <slepc/private/epsimpl.h>                /*I "slepceps.h" I*/

 30: typedef struct {
 31:   PetscBool explicitmatrix;
 32:   EPS       eps;
 33:   Mat       mat;
 34:   Vec       x1,x2,y1,y2;
 35: } SVD_CYCLIC;

 39: static PetscErrorCode MatMult_Cyclic(Mat B,Vec x,Vec y)
 40: {
 41:   PetscErrorCode    ierr;
 42:   SVD               svd;
 43:   SVD_CYCLIC        *cyclic;
 44:   const PetscScalar *px;
 45:   PetscScalar       *py;
 46:   PetscInt          m;

 49:   MatShellGetContext(B,(void**)&svd);
 50:   cyclic = (SVD_CYCLIC*)svd->data;
 51:   SVDMatGetLocalSize(svd,&m,NULL);
 52:   VecGetArrayRead(x,&px);
 53:   VecGetArray(y,&py);
 54:   VecPlaceArray(cyclic->x1,px);
 55:   VecPlaceArray(cyclic->x2,px+m);
 56:   VecPlaceArray(cyclic->y1,py);
 57:   VecPlaceArray(cyclic->y2,py+m);
 58:   SVDMatMult(svd,PETSC_FALSE,cyclic->x2,cyclic->y1);
 59:   SVDMatMult(svd,PETSC_TRUE,cyclic->x1,cyclic->y2);
 60:   VecResetArray(cyclic->x1);
 61:   VecResetArray(cyclic->x2);
 62:   VecResetArray(cyclic->y1);
 63:   VecResetArray(cyclic->y2);
 64:   VecRestoreArrayRead(x,&px);
 65:   VecRestoreArray(y,&py);
 66:   return(0);
 67: }

 71: static PetscErrorCode MatGetDiagonal_Cyclic(Mat B,Vec diag)
 72: {

 76:   VecSet(diag,0.0);
 77:   return(0);
 78: }

 82: PetscErrorCode SVDSetUp_Cyclic(SVD svd)
 83: {
 84:   PetscErrorCode    ierr;
 85:   SVD_CYCLIC        *cyclic = (SVD_CYCLIC*)svd->data;
 86:   PetscInt          M,N,m,n,i,isl,Istart,Iend;
 87:   const PetscScalar *isa;
 88:   PetscScalar       *va;
 89:   PetscBool         trackall,gpu,issinv;
 90:   Vec               v;
 91:   Mat               Zm,Zn;
 92:   ST                st;

 95:   PetscObjectTypeCompareAny((PetscObject)svd->A,&gpu,MATSEQAIJCUSP,MATMPIAIJCUSP,MATSEQAIJCUSPARSE,MATMPIAIJCUSPARSE,"");
 96:   if (gpu) SETERRQ(PetscObjectComm((PetscObject)svd),PETSC_ERR_SUP,"Solver not implemented for GPU matrices");
 97:   SVDMatGetSize(svd,&M,&N);
 98:   SVDMatGetLocalSize(svd,&m,&n);
 99:   if (!cyclic->mat) {
100:     if (cyclic->explicitmatrix) {
101:       if (!svd->AT) SETERRQ(PetscObjectComm((PetscObject)svd),PETSC_ERR_SUP,"Cannot use explicit cyclic matrix with implicit transpose");
102:       MatCreate(PetscObjectComm((PetscObject)svd),&Zm);
103:       MatSetSizes(Zm,m,m,M,M);
104:       MatSetFromOptions(Zm);
105:       MatSetUp(Zm);
106:       MatGetOwnershipRange(Zm,&Istart,&Iend);
107:       for (i=Istart;i<Iend;i++) {
108:         MatSetValue(Zm,i,i,0.0,INSERT_VALUES);
109:       }
110:       MatAssemblyBegin(Zm,MAT_FINAL_ASSEMBLY);
111:       MatAssemblyEnd(Zm,MAT_FINAL_ASSEMBLY);
112:       MatCreate(PetscObjectComm((PetscObject)svd),&Zn);
113:       MatSetSizes(Zn,n,n,N,N);
114:       MatSetFromOptions(Zn);
115:       MatSetUp(Zn);
116:       MatGetOwnershipRange(Zn,&Istart,&Iend);
117:       for (i=Istart;i<Iend;i++) {
118:         MatSetValue(Zn,i,i,0.0,INSERT_VALUES);
119:       }
120:       MatAssemblyBegin(Zn,MAT_FINAL_ASSEMBLY);
121:       MatAssemblyEnd(Zn,MAT_FINAL_ASSEMBLY);
122:       SlepcMatTile(1.0,Zm,1.0,svd->A,1.0,svd->AT,1.0,Zn,&cyclic->mat);
123:       PetscLogObjectParent((PetscObject)svd,(PetscObject)cyclic->mat);
124:       MatDestroy(&Zm);
125:       MatDestroy(&Zn);
126:     } else {
127:       VecCreateMPIWithArray(PetscObjectComm((PetscObject)svd),1,m,M,NULL,&cyclic->x1);
128:       VecCreateMPIWithArray(PetscObjectComm((PetscObject)svd),1,n,N,NULL,&cyclic->x2);
129:       VecCreateMPIWithArray(PetscObjectComm((PetscObject)svd),1,m,M,NULL,&cyclic->y1);
130:       VecCreateMPIWithArray(PetscObjectComm((PetscObject)svd),1,n,N,NULL,&cyclic->y2);
131:       PetscLogObjectParent((PetscObject)svd,(PetscObject)cyclic->x1);
132:       PetscLogObjectParent((PetscObject)svd,(PetscObject)cyclic->x2);
133:       PetscLogObjectParent((PetscObject)svd,(PetscObject)cyclic->y1);
134:       PetscLogObjectParent((PetscObject)svd,(PetscObject)cyclic->y2);
135:       MatCreateShell(PetscObjectComm((PetscObject)svd),m+n,m+n,M+N,M+N,svd,&cyclic->mat);
136:       MatShellSetOperation(cyclic->mat,MATOP_MULT,(void(*)(void))MatMult_Cyclic);
137:       MatShellSetOperation(cyclic->mat,MATOP_GET_DIAGONAL,(void(*)(void))MatGetDiagonal_Cyclic);
138:     }
139:     PetscLogObjectParent((PetscObject)svd,(PetscObject)cyclic->mat);
140:   }

142:   if (!cyclic->eps) { SVDCyclicGetEPS(svd,&cyclic->eps); }
143:   EPSSetOperators(cyclic->eps,cyclic->mat,NULL);
144:   EPSSetProblemType(cyclic->eps,EPS_HEP);
145:   if (svd->which == SVD_LARGEST) {
146:     EPSGetST(cyclic->eps,&st);
147:     PetscObjectTypeCompare((PetscObject)st,STSINVERT,&issinv);
148:     if (issinv) {
149:       EPSSetWhichEigenpairs(cyclic->eps,EPS_TARGET_MAGNITUDE);
150:     } else {
151:       EPSSetWhichEigenpairs(cyclic->eps,EPS_LARGEST_REAL);
152:     }
153:   } else {
154:     EPSSetEigenvalueComparison(cyclic->eps,SlepcCompareSmallestPosReal,NULL);
155:     EPSSetTarget(cyclic->eps,0.0);
156:   }
157:   EPSSetDimensions(cyclic->eps,svd->nsv,svd->ncv?svd->ncv:PETSC_DEFAULT,svd->mpd?svd->mpd:PETSC_DEFAULT);
158:   EPSSetTolerances(cyclic->eps,svd->tol==PETSC_DEFAULT?SLEPC_DEFAULT_TOL/10.0:svd->tol,svd->max_it?svd->max_it:PETSC_DEFAULT);
159:   switch (svd->conv) {
160:   case SVD_CONV_ABS:
161:     EPSSetConvergenceTest(cyclic->eps,EPS_CONV_ABS);break;
162:   case SVD_CONV_REL:
163:     EPSSetConvergenceTest(cyclic->eps,EPS_CONV_REL);break;
164:   case SVD_CONV_USER:
165:     SETERRQ(PetscObjectComm((PetscObject)svd),PETSC_ERR_SUP,"User-defined convergence test not supported in this solver");
166:   }
167:   if (svd->stop!=SVD_STOP_BASIC) SETERRQ(PetscObjectComm((PetscObject)svd),PETSC_ERR_SUP,"User-defined stopping test not supported in this solver");
168:   /* Transfer the trackall option from svd to eps */
169:   SVDGetTrackAll(svd,&trackall);
170:   EPSSetTrackAll(cyclic->eps,trackall);
171:   /* Transfer the initial subspace from svd to eps */
172:   if (svd->nini<0 || svd->ninil<0) {
173:     for (i=0;i<-PetscMin(svd->nini,svd->ninil);i++) {
174:       MatCreateVecs(cyclic->mat,&v,NULL);
175:       VecGetArray(v,&va);
176:       if (i<-svd->ninil) {
177:         VecGetSize(svd->ISL[i],&isl);
178:         if (isl!=m) SETERRQ(PetscObjectComm((PetscObject)svd),PETSC_ERR_SUP,"Size mismatch for left initial vector");
179:         VecGetArrayRead(svd->ISL[i],&isa);
180:         PetscMemcpy(va,isa,sizeof(PetscScalar)*m);
181:         VecRestoreArrayRead(svd->IS[i],&isa);
182:       } else {
183:         PetscMemzero(&va,sizeof(PetscScalar)*m);
184:       }
185:       if (i<-svd->nini) {
186:         VecGetSize(svd->IS[i],&isl);
187:         if (isl!=n) SETERRQ(PetscObjectComm((PetscObject)svd),PETSC_ERR_SUP,"Size mismatch for right initial vector");
188:         VecGetArrayRead(svd->IS[i],&isa);
189:         PetscMemcpy(va+m,isa,sizeof(PetscScalar)*n);
190:         VecRestoreArrayRead(svd->IS[i],&isa);
191:       } else {
192:         PetscMemzero(va+m,sizeof(PetscScalar)*n);
193:       }
194:       VecRestoreArray(v,&va);
195:       VecDestroy(&svd->IS[i]);
196:       svd->IS[i] = v;
197:     }
198:     svd->nini = PetscMin(svd->nini,svd->ninil);
199:     EPSSetInitialSpace(cyclic->eps,-svd->nini,svd->IS);
200:     SlepcBasisDestroy_Private(&svd->nini,&svd->IS);
201:     SlepcBasisDestroy_Private(&svd->ninil,&svd->ISL);
202:   }
203:   EPSSetUp(cyclic->eps);
204:   EPSGetDimensions(cyclic->eps,NULL,&svd->ncv,&svd->mpd);
205:   svd->ncv = PetscMin(svd->ncv,PetscMin(M,N));
206:   EPSGetTolerances(cyclic->eps,NULL,&svd->max_it);
207:   if (svd->tol==PETSC_DEFAULT) svd->tol = SLEPC_DEFAULT_TOL;

209:   svd->leftbasis = PETSC_TRUE;
210:   SVDAllocateSolution(svd,0);
211:   return(0);
212: }

216: PetscErrorCode SVDSolve_Cyclic(SVD svd)
217: {
218:   PetscErrorCode    ierr;
219:   SVD_CYCLIC        *cyclic = (SVD_CYCLIC*)svd->data;
220:   PetscInt          i,j,M,N,m,n;
221:   PetscScalar       sigma;
222:   const PetscScalar *px;
223:   Vec               x,x1,x2;

226:   EPSSolve(cyclic->eps);
227:   EPSGetConverged(cyclic->eps,&svd->nconv);
228:   EPSGetIterationNumber(cyclic->eps,&svd->its);
229:   EPSGetConvergedReason(cyclic->eps,(EPSConvergedReason*)&svd->reason);

231:   MatCreateVecs(cyclic->mat,&x,NULL);
232:   SVDMatGetSize(svd,&M,&N);
233:   SVDMatGetLocalSize(svd,&m,&n);
234:   VecCreateMPIWithArray(PetscObjectComm((PetscObject)svd),1,m,M,NULL,&x1);
235:   VecCreateMPIWithArray(PetscObjectComm((PetscObject)svd),1,n,N,NULL,&x2);
236:   for (i=0,j=0;i<svd->nconv;i++) {
237:     EPSGetEigenpair(cyclic->eps,i,&sigma,NULL,x,NULL);
238:     if (PetscRealPart(sigma) > 0.0) {
239:       svd->sigma[j] = PetscRealPart(sigma);
240:       VecGetArrayRead(x,&px);
241:       VecPlaceArray(x1,px);
242:       VecPlaceArray(x2,px+m);
243:       BVInsertVec(svd->U,j,x1);
244:       BVScaleColumn(svd->U,j,1.0/PetscSqrtReal(2.0));
245:       BVInsertVec(svd->V,j,x2);
246:       BVScaleColumn(svd->V,j,1.0/PetscSqrtReal(2.0));
247:       VecResetArray(x1);
248:       VecResetArray(x2);
249:       VecRestoreArrayRead(x,&px);
250:       j++;
251:     }
252:   }
253:   svd->nconv = j;

255:   VecDestroy(&x);
256:   VecDestroy(&x1);
257:   VecDestroy(&x2);
258:   return(0);
259: }

263: static PetscErrorCode EPSMonitor_Cyclic(EPS eps,PetscInt its,PetscInt nconv,PetscScalar *eigr,PetscScalar *eigi,PetscReal *errest,PetscInt nest,void *ctx)
264: {
265:   PetscInt       i,j;
266:   SVD            svd = (SVD)ctx;
267:   PetscScalar    er,ei;

271:   nconv = 0;
272:   for (i=0,j=0;i<PetscMin(nest,svd->ncv);i++) {
273:     er = eigr[i]; ei = eigi[i];
274:     STBackTransform(eps->st,1,&er,&ei);
275:     if (PetscRealPart(er) > 0.0) {
276:       svd->sigma[j] = PetscRealPart(er);
277:       svd->errest[j] = errest[i];
278:       if (errest[i] && errest[i] < svd->tol) nconv++;
279:       j++;
280:     }
281:   }
282:   nest = j;
283:   SVDMonitor(svd,its,nconv,svd->sigma,svd->errest,nest);
284:   return(0);
285: }

289: PetscErrorCode SVDSetFromOptions_Cyclic(PetscOptionItems *PetscOptionsObject,SVD svd)
290: {
292:   PetscBool      set,val;
293:   SVD_CYCLIC     *cyclic = (SVD_CYCLIC*)svd->data;
294:   ST             st;

297:   PetscOptionsHead(PetscOptionsObject,"SVD Cyclic Options");
298:   PetscOptionsBool("-svd_cyclic_explicitmatrix","Use cyclic explicit matrix","SVDCyclicSetExplicitMatrix",cyclic->explicitmatrix,&val,&set);
299:   if (set) {
300:     SVDCyclicSetExplicitMatrix(svd,val);
301:   }
302:   if (!cyclic->eps) { SVDCyclicGetEPS(svd,&cyclic->eps); }
303:   EPSSetFromOptions(cyclic->eps);
304:   if (!cyclic->explicitmatrix) {
305:     /* use as default an ST with shell matrix and Jacobi */
306:     EPSGetST(cyclic->eps,&st);
307:     STSetMatMode(st,ST_MATMODE_SHELL);
308:   }
309:   PetscOptionsTail();
310:   return(0);
311: }

315: static PetscErrorCode SVDCyclicSetExplicitMatrix_Cyclic(SVD svd,PetscBool explicitmatrix)
316: {
317:   SVD_CYCLIC *cyclic = (SVD_CYCLIC*)svd->data;

320:   cyclic->explicitmatrix = explicitmatrix;
321:   return(0);
322: }

326: /*@
327:    SVDCyclicSetExplicitMatrix - Indicate if the eigensolver operator
328:    H(A) = [ 0  A ; A^T 0 ] must be computed explicitly.

330:    Logically Collective on SVD

332:    Input Parameters:
333: +  svd      - singular value solver
334: -  explicit - boolean flag indicating if H(A) is built explicitly

336:    Options Database Key:
337: .  -svd_cyclic_explicitmatrix <boolean> - Indicates the boolean flag

339:    Level: advanced

341: .seealso: SVDCyclicGetExplicitMatrix()
342: @*/
343: PetscErrorCode SVDCyclicSetExplicitMatrix(SVD svd,PetscBool explicitmatrix)
344: {

350:   PetscTryMethod(svd,"SVDCyclicSetExplicitMatrix_C",(SVD,PetscBool),(svd,explicitmatrix));
351:   return(0);
352: }

356: static PetscErrorCode SVDCyclicGetExplicitMatrix_Cyclic(SVD svd,PetscBool *explicitmatrix)
357: {
358:   SVD_CYCLIC *cyclic = (SVD_CYCLIC*)svd->data;

361:   *explicitmatrix = cyclic->explicitmatrix;
362:   return(0);
363: }

367: /*@
368:    SVDCyclicGetExplicitMatrix - Returns the flag indicating if H(A) is built explicitly

370:    Not Collective

372:    Input Parameter:
373: .  svd  - singular value solver

375:    Output Parameter:
376: .  explicit - the mode flag

378:    Level: advanced

380: .seealso: SVDCyclicSetExplicitMatrix()
381: @*/
382: PetscErrorCode SVDCyclicGetExplicitMatrix(SVD svd,PetscBool *explicitmatrix)
383: {

389:   PetscUseMethod(svd,"SVDCyclicGetExplicitMatrix_C",(SVD,PetscBool*),(svd,explicitmatrix));
390:   return(0);
391: }

395: static PetscErrorCode SVDCyclicSetEPS_Cyclic(SVD svd,EPS eps)
396: {
397:   PetscErrorCode  ierr;
398:   SVD_CYCLIC      *cyclic = (SVD_CYCLIC*)svd->data;

401:   PetscObjectReference((PetscObject)eps);
402:   EPSDestroy(&cyclic->eps);
403:   cyclic->eps = eps;
404:   PetscLogObjectParent((PetscObject)svd,(PetscObject)cyclic->eps);
405:   svd->state = SVD_STATE_INITIAL;
406:   return(0);
407: }

411: /*@
412:    SVDCyclicSetEPS - Associate an eigensolver object (EPS) to the
413:    singular value solver.

415:    Collective on SVD

417:    Input Parameters:
418: +  svd - singular value solver
419: -  eps - the eigensolver object

421:    Level: advanced

423: .seealso: SVDCyclicGetEPS()
424: @*/
425: PetscErrorCode SVDCyclicSetEPS(SVD svd,EPS eps)
426: {

433:   PetscTryMethod(svd,"SVDCyclicSetEPS_C",(SVD,EPS),(svd,eps));
434:   return(0);
435: }

439: static PetscErrorCode SVDCyclicGetEPS_Cyclic(SVD svd,EPS *eps)
440: {
442:   SVD_CYCLIC     *cyclic = (SVD_CYCLIC*)svd->data;

445:   if (!cyclic->eps) {
446:     EPSCreate(PetscObjectComm((PetscObject)svd),&cyclic->eps);
447:     EPSSetOptionsPrefix(cyclic->eps,((PetscObject)svd)->prefix);
448:     EPSAppendOptionsPrefix(cyclic->eps,"svd_cyclic_");
449:     PetscObjectIncrementTabLevel((PetscObject)cyclic->eps,(PetscObject)svd,1);
450:     PetscLogObjectParent((PetscObject)svd,(PetscObject)cyclic->eps);
451:     EPSSetWhichEigenpairs(cyclic->eps,EPS_LARGEST_REAL);
452:     EPSMonitorSet(cyclic->eps,EPSMonitor_Cyclic,svd,NULL);
453:   }
454:   *eps = cyclic->eps;
455:   return(0);
456: }

460: /*@
461:    SVDCyclicGetEPS - Retrieve the eigensolver object (EPS) associated
462:    to the singular value solver.

464:    Not Collective

466:    Input Parameter:
467: .  svd - singular value solver

469:    Output Parameter:
470: .  eps - the eigensolver object

472:    Level: advanced

474: .seealso: SVDCyclicSetEPS()
475: @*/
476: PetscErrorCode SVDCyclicGetEPS(SVD svd,EPS *eps)
477: {

483:   PetscUseMethod(svd,"SVDCyclicGetEPS_C",(SVD,EPS*),(svd,eps));
484:   return(0);
485: }

489: PetscErrorCode SVDView_Cyclic(SVD svd,PetscViewer viewer)
490: {
492:   SVD_CYCLIC     *cyclic = (SVD_CYCLIC*)svd->data;
493:   PetscBool      isascii;

496:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);
497:   if (isascii) {
498:     if (!cyclic->eps) { SVDCyclicGetEPS(svd,&cyclic->eps); }
499:     PetscViewerASCIIPrintf(viewer,"  Cyclic: %s matrix\n",cyclic->explicitmatrix?"explicit":"implicit");
500:     PetscViewerASCIIPushTab(viewer);
501:     EPSView(cyclic->eps,viewer);
502:     PetscViewerASCIIPopTab(viewer);
503:   }
504:   return(0);
505: }

509: PetscErrorCode SVDReset_Cyclic(SVD svd)
510: {
512:   SVD_CYCLIC     *cyclic = (SVD_CYCLIC*)svd->data;

515:   if (!cyclic->eps) { EPSReset(cyclic->eps); }
516:   MatDestroy(&cyclic->mat);
517:   VecDestroy(&cyclic->x1);
518:   VecDestroy(&cyclic->x2);
519:   VecDestroy(&cyclic->y1);
520:   VecDestroy(&cyclic->y2);
521:   return(0);
522: }

526: PetscErrorCode SVDDestroy_Cyclic(SVD svd)
527: {
529:   SVD_CYCLIC     *cyclic = (SVD_CYCLIC*)svd->data;

532:   EPSDestroy(&cyclic->eps);
533:   PetscFree(svd->data);
534:   PetscObjectComposeFunction((PetscObject)svd,"SVDCyclicSetEPS_C",NULL);
535:   PetscObjectComposeFunction((PetscObject)svd,"SVDCyclicGetEPS_C",NULL);
536:   PetscObjectComposeFunction((PetscObject)svd,"SVDCyclicSetExplicitMatrix_C",NULL);
537:   PetscObjectComposeFunction((PetscObject)svd,"SVDCyclicGetExplicitMatrix_C",NULL);
538:   return(0);
539: }

543: PETSC_EXTERN PetscErrorCode SVDCreate_Cyclic(SVD svd)
544: {
546:   SVD_CYCLIC     *cyclic;

549:   PetscNewLog(svd,&cyclic);
550:   svd->data                      = (void*)cyclic;
551:   svd->ops->solve                = SVDSolve_Cyclic;
552:   svd->ops->setup                = SVDSetUp_Cyclic;
553:   svd->ops->setfromoptions       = SVDSetFromOptions_Cyclic;
554:   svd->ops->destroy              = SVDDestroy_Cyclic;
555:   svd->ops->reset                = SVDReset_Cyclic;
556:   svd->ops->view                 = SVDView_Cyclic;
557:   PetscObjectComposeFunction((PetscObject)svd,"SVDCyclicSetEPS_C",SVDCyclicSetEPS_Cyclic);
558:   PetscObjectComposeFunction((PetscObject)svd,"SVDCyclicGetEPS_C",SVDCyclicGetEPS_Cyclic);
559:   PetscObjectComposeFunction((PetscObject)svd,"SVDCyclicSetExplicitMatrix_C",SVDCyclicSetExplicitMatrix_Cyclic);
560:   PetscObjectComposeFunction((PetscObject)svd,"SVDCyclicGetExplicitMatrix_C",SVDCyclicGetExplicitMatrix_Cyclic);
561:   return(0);
562: }