Actual source code: nepbasic.c

slepc-3.18.3 2023-03-24
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain

  6:    This file is part of SLEPc.
  7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
  8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  9: */
 10: /*
 11:    Basic NEP routines
 12: */

 14: #include <slepc/private/nepimpl.h>

 16: /* Logging support */
 17: PetscClassId      NEP_CLASSID = 0;
 18: PetscLogEvent     NEP_SetUp = 0,NEP_Solve = 0,NEP_Refine = 0,NEP_FunctionEval = 0,NEP_JacobianEval = 0,NEP_Resolvent = 0,NEP_CISS_SVD = 0;

 20: /* List of registered NEP routines */
 21: PetscFunctionList NEPList = NULL;
 22: PetscBool         NEPRegisterAllCalled = PETSC_FALSE;

 24: /* List of registered NEP monitors */
 25: PetscFunctionList NEPMonitorList              = NULL;
 26: PetscFunctionList NEPMonitorCreateList        = NULL;
 27: PetscFunctionList NEPMonitorDestroyList       = NULL;
 28: PetscBool         NEPMonitorRegisterAllCalled = PETSC_FALSE;

 30: /*@
 31:    NEPCreate - Creates the default NEP context.

 33:    Collective

 35:    Input Parameter:
 36: .  comm - MPI communicator

 38:    Output Parameter:
 39: .  outnep - location to put the NEP context

 41:    Level: beginner

 43: .seealso: NEPSetUp(), NEPSolve(), NEPDestroy(), NEP
 44: @*/
 45: PetscErrorCode NEPCreate(MPI_Comm comm,NEP *outnep)
 46: {
 47:   NEP            nep;

 50:   *outnep = NULL;
 51:   NEPInitializePackage();
 52:   SlepcHeaderCreate(nep,NEP_CLASSID,"NEP","Nonlinear Eigenvalue Problem","NEP",comm,NEPDestroy,NEPView);

 54:   nep->max_it          = PETSC_DEFAULT;
 55:   nep->nev             = 1;
 56:   nep->ncv             = PETSC_DEFAULT;
 57:   nep->mpd             = PETSC_DEFAULT;
 58:   nep->nini            = 0;
 59:   nep->target          = 0.0;
 60:   nep->tol             = PETSC_DEFAULT;
 61:   nep->conv            = NEP_CONV_REL;
 62:   nep->stop            = NEP_STOP_BASIC;
 63:   nep->which           = (NEPWhich)0;
 64:   nep->problem_type    = (NEPProblemType)0;
 65:   nep->refine          = NEP_REFINE_NONE;
 66:   nep->npart           = 1;
 67:   nep->rtol            = PETSC_DEFAULT;
 68:   nep->rits            = PETSC_DEFAULT;
 69:   nep->scheme          = (NEPRefineScheme)0;
 70:   nep->trackall        = PETSC_FALSE;
 71:   nep->twosided        = PETSC_FALSE;

 73:   nep->computefunction = NULL;
 74:   nep->computejacobian = NULL;
 75:   nep->functionctx     = NULL;
 76:   nep->jacobianctx     = NULL;
 77:   nep->converged       = NEPConvergedRelative;
 78:   nep->convergeduser   = NULL;
 79:   nep->convergeddestroy= NULL;
 80:   nep->stopping        = NEPStoppingBasic;
 81:   nep->stoppinguser    = NULL;
 82:   nep->stoppingdestroy = NULL;
 83:   nep->convergedctx    = NULL;
 84:   nep->stoppingctx     = NULL;
 85:   nep->numbermonitors  = 0;

 87:   nep->ds              = NULL;
 88:   nep->V               = NULL;
 89:   nep->W               = NULL;
 90:   nep->rg              = NULL;
 91:   nep->function        = NULL;
 92:   nep->function_pre    = NULL;
 93:   nep->jacobian        = NULL;
 94:   nep->A               = NULL;
 95:   nep->f               = NULL;
 96:   nep->nt              = 0;
 97:   nep->mstr            = UNKNOWN_NONZERO_PATTERN;
 98:   nep->P               = NULL;
 99:   nep->mstrp           = UNKNOWN_NONZERO_PATTERN;
100:   nep->IS              = NULL;
101:   nep->eigr            = NULL;
102:   nep->eigi            = NULL;
103:   nep->errest          = NULL;
104:   nep->perm            = NULL;
105:   nep->nwork           = 0;
106:   nep->work            = NULL;
107:   nep->data            = NULL;

109:   nep->state           = NEP_STATE_INITIAL;
110:   nep->nconv           = 0;
111:   nep->its             = 0;
112:   nep->n               = 0;
113:   nep->nloc            = 0;
114:   nep->nrma            = NULL;
115:   nep->fui             = (NEPUserInterface)0;
116:   nep->useds           = PETSC_FALSE;
117:   nep->resolvent       = NULL;
118:   nep->reason          = NEP_CONVERGED_ITERATING;

120:   PetscNew(&nep->sc);
121:   *outnep = nep;
122:   return 0;
123: }

125: /*@C
126:    NEPSetType - Selects the particular solver to be used in the NEP object.

128:    Logically Collective on nep

130:    Input Parameters:
131: +  nep      - the nonlinear eigensolver context
132: -  type     - a known method

134:    Options Database Key:
135: .  -nep_type <method> - Sets the method; use -help for a list
136:     of available methods

138:    Notes:
139:    See "slepc/include/slepcnep.h" for available methods.

141:    Normally, it is best to use the NEPSetFromOptions() command and
142:    then set the NEP type from the options database rather than by using
143:    this routine.  Using the options database provides the user with
144:    maximum flexibility in evaluating the different available methods.
145:    The NEPSetType() routine is provided for those situations where it
146:    is necessary to set the iterative solver independently of the command
147:    line or options database.

149:    Level: intermediate

151: .seealso: NEPType
152: @*/
153: PetscErrorCode NEPSetType(NEP nep,NEPType type)
154: {
155:   PetscErrorCode (*r)(NEP);
156:   PetscBool      match;


161:   PetscObjectTypeCompare((PetscObject)nep,type,&match);
162:   if (match) return 0;

164:   PetscFunctionListFind(NEPList,type,&r);

167:   PetscTryTypeMethod(nep,destroy);
168:   PetscMemzero(nep->ops,sizeof(struct _NEPOps));

170:   nep->state = NEP_STATE_INITIAL;
171:   PetscObjectChangeTypeName((PetscObject)nep,type);
172:   (*r)(nep);
173:   return 0;
174: }

176: /*@C
177:    NEPGetType - Gets the NEP type as a string from the NEP object.

179:    Not Collective

181:    Input Parameter:
182: .  nep - the eigensolver context

184:    Output Parameter:
185: .  type - name of NEP method

187:    Level: intermediate

189: .seealso: NEPSetType()
190: @*/
191: PetscErrorCode NEPGetType(NEP nep,NEPType *type)
192: {
195:   *type = ((PetscObject)nep)->type_name;
196:   return 0;
197: }

199: /*@C
200:    NEPRegister - Adds a method to the nonlinear eigenproblem solver package.

202:    Not Collective

204:    Input Parameters:
205: +  name - name of a new user-defined solver
206: -  function - routine to create the solver context

208:    Notes:
209:    NEPRegister() may be called multiple times to add several user-defined solvers.

211:    Sample usage:
212: .vb
213:     NEPRegister("my_solver",MySolverCreate);
214: .ve

216:    Then, your solver can be chosen with the procedural interface via
217: $     NEPSetType(nep,"my_solver")
218:    or at runtime via the option
219: $     -nep_type my_solver

221:    Level: advanced

223: .seealso: NEPRegisterAll()
224: @*/
225: PetscErrorCode NEPRegister(const char *name,PetscErrorCode (*function)(NEP))
226: {
227:   NEPInitializePackage();
228:   PetscFunctionListAdd(&NEPList,name,function);
229:   return 0;
230: }

232: /*@C
233:    NEPMonitorRegister - Adds NEP monitor routine.

235:    Not Collective

237:    Input Parameters:
238: +  name    - name of a new monitor routine
239: .  vtype   - a PetscViewerType for the output
240: .  format  - a PetscViewerFormat for the output
241: .  monitor - monitor routine
242: .  create  - creation routine, or NULL
243: -  destroy - destruction routine, or NULL

245:    Notes:
246:    NEPMonitorRegister() may be called multiple times to add several user-defined monitors.

248:    Sample usage:
249: .vb
250:    NEPMonitorRegister("my_monitor",PETSCVIEWERASCII,PETSC_VIEWER_ASCII_INFO_DETAIL,MyMonitor,NULL,NULL);
251: .ve

253:    Then, your monitor can be chosen with the procedural interface via
254: $      NEPMonitorSetFromOptions(nep,"-nep_monitor_my_monitor","my_monitor",NULL)
255:    or at runtime via the option
256: $      -nep_monitor_my_monitor

258:    Level: advanced

260: .seealso: NEPMonitorRegisterAll()
261: @*/
262: PetscErrorCode NEPMonitorRegister(const char name[],PetscViewerType vtype,PetscViewerFormat format,PetscErrorCode (*monitor)(NEP,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,PetscViewerAndFormat*),PetscErrorCode (*create)(PetscViewer,PetscViewerFormat,void*,PetscViewerAndFormat**),PetscErrorCode (*destroy)(PetscViewerAndFormat**))
263: {
264:   char           key[PETSC_MAX_PATH_LEN];

266:   NEPInitializePackage();
267:   SlepcMonitorMakeKey_Internal(name,vtype,format,key);
268:   PetscFunctionListAdd(&NEPMonitorList,key,monitor);
269:   if (create)  PetscFunctionListAdd(&NEPMonitorCreateList,key,create);
270:   if (destroy) PetscFunctionListAdd(&NEPMonitorDestroyList,key,destroy);
271:   return 0;
272: }

274: /*
275:    NEPReset_Problem - Destroys the problem matrices.
276: */
277: PetscErrorCode NEPReset_Problem(NEP nep)
278: {
279:   PetscInt       i;

282:   MatDestroy(&nep->function);
283:   MatDestroy(&nep->function_pre);
284:   MatDestroy(&nep->jacobian);
285:   if (nep->fui==NEP_USER_INTERFACE_SPLIT) {
286:     MatDestroyMatrices(nep->nt,&nep->A);
287:     for (i=0;i<nep->nt;i++) FNDestroy(&nep->f[i]);
288:     PetscFree(nep->f);
289:     PetscFree(nep->nrma);
290:     if (nep->P) MatDestroyMatrices(nep->nt,&nep->P);
291:     nep->nt = 0;
292:   }
293:   return 0;
294: }
295: /*@
296:    NEPReset - Resets the NEP context to the initial state (prior to setup)
297:    and destroys any allocated Vecs and Mats.

299:    Collective on nep

301:    Input Parameter:
302: .  nep - eigensolver context obtained from NEPCreate()

304:    Level: advanced

306: .seealso: NEPDestroy()
307: @*/
308: PetscErrorCode NEPReset(NEP nep)
309: {
311:   if (!nep) return 0;
312:   PetscTryTypeMethod(nep,reset);
313:   if (nep->refineksp) KSPReset(nep->refineksp);
314:   NEPReset_Problem(nep);
315:   BVDestroy(&nep->V);
316:   BVDestroy(&nep->W);
317:   VecDestroyVecs(nep->nwork,&nep->work);
318:   MatDestroy(&nep->resolvent);
319:   nep->nwork = 0;
320:   nep->state = NEP_STATE_INITIAL;
321:   return 0;
322: }

324: /*@C
325:    NEPDestroy - Destroys the NEP context.

327:    Collective on nep

329:    Input Parameter:
330: .  nep - eigensolver context obtained from NEPCreate()

332:    Level: beginner

334: .seealso: NEPCreate(), NEPSetUp(), NEPSolve()
335: @*/
336: PetscErrorCode NEPDestroy(NEP *nep)
337: {
338:   if (!*nep) return 0;
340:   if (--((PetscObject)(*nep))->refct > 0) { *nep = NULL; return 0; }
341:   NEPReset(*nep);
342:   PetscTryTypeMethod(*nep,destroy);
343:   if ((*nep)->eigr) PetscFree4((*nep)->eigr,(*nep)->eigi,(*nep)->errest,(*nep)->perm);
344:   RGDestroy(&(*nep)->rg);
345:   DSDestroy(&(*nep)->ds);
346:   KSPDestroy(&(*nep)->refineksp);
347:   PetscSubcommDestroy(&(*nep)->refinesubc);
348:   PetscFree((*nep)->sc);
349:   /* just in case the initial vectors have not been used */
350:   SlepcBasisDestroy_Private(&(*nep)->nini,&(*nep)->IS);
351:   if ((*nep)->convergeddestroy) (*(*nep)->convergeddestroy)((*nep)->convergedctx);
352:   NEPMonitorCancel(*nep);
353:   PetscHeaderDestroy(nep);
354:   return 0;
355: }

357: /*@
358:    NEPSetBV - Associates a basis vectors object to the nonlinear eigensolver.

360:    Collective on nep

362:    Input Parameters:
363: +  nep - eigensolver context obtained from NEPCreate()
364: -  bv  - the basis vectors object

366:    Note:
367:    Use NEPGetBV() to retrieve the basis vectors context (for example,
368:    to free it at the end of the computations).

370:    Level: advanced

372: .seealso: NEPGetBV()
373: @*/
374: PetscErrorCode NEPSetBV(NEP nep,BV bv)
375: {
379:   PetscObjectReference((PetscObject)bv);
380:   BVDestroy(&nep->V);
381:   nep->V = bv;
382:   return 0;
383: }

385: /*@
386:    NEPGetBV - Obtain the basis vectors object associated to the nonlinear
387:    eigensolver object.

389:    Not Collective

391:    Input Parameters:
392: .  nep - eigensolver context obtained from NEPCreate()

394:    Output Parameter:
395: .  bv - basis vectors context

397:    Level: advanced

399: .seealso: NEPSetBV()
400: @*/
401: PetscErrorCode NEPGetBV(NEP nep,BV *bv)
402: {
405:   if (!nep->V) {
406:     BVCreate(PetscObjectComm((PetscObject)nep),&nep->V);
407:     PetscObjectIncrementTabLevel((PetscObject)nep->V,(PetscObject)nep,0);
408:     PetscObjectSetOptions((PetscObject)nep->V,((PetscObject)nep)->options);
409:   }
410:   *bv = nep->V;
411:   return 0;
412: }

414: /*@
415:    NEPSetRG - Associates a region object to the nonlinear eigensolver.

417:    Collective on nep

419:    Input Parameters:
420: +  nep - eigensolver context obtained from NEPCreate()
421: -  rg  - the region object

423:    Note:
424:    Use NEPGetRG() to retrieve the region context (for example,
425:    to free it at the end of the computations).

427:    Level: advanced

429: .seealso: NEPGetRG()
430: @*/
431: PetscErrorCode NEPSetRG(NEP nep,RG rg)
432: {
434:   if (rg) {
437:   }
438:   PetscObjectReference((PetscObject)rg);
439:   RGDestroy(&nep->rg);
440:   nep->rg = rg;
441:   return 0;
442: }

444: /*@
445:    NEPGetRG - Obtain the region object associated to the
446:    nonlinear eigensolver object.

448:    Not Collective

450:    Input Parameters:
451: .  nep - eigensolver context obtained from NEPCreate()

453:    Output Parameter:
454: .  rg - region context

456:    Level: advanced

458: .seealso: NEPSetRG()
459: @*/
460: PetscErrorCode NEPGetRG(NEP nep,RG *rg)
461: {
464:   if (!nep->rg) {
465:     RGCreate(PetscObjectComm((PetscObject)nep),&nep->rg);
466:     PetscObjectIncrementTabLevel((PetscObject)nep->rg,(PetscObject)nep,0);
467:     PetscObjectSetOptions((PetscObject)nep->rg,((PetscObject)nep)->options);
468:   }
469:   *rg = nep->rg;
470:   return 0;
471: }

473: /*@
474:    NEPSetDS - Associates a direct solver object to the nonlinear eigensolver.

476:    Collective on nep

478:    Input Parameters:
479: +  nep - eigensolver context obtained from NEPCreate()
480: -  ds  - the direct solver object

482:    Note:
483:    Use NEPGetDS() to retrieve the direct solver context (for example,
484:    to free it at the end of the computations).

486:    Level: advanced

488: .seealso: NEPGetDS()
489: @*/
490: PetscErrorCode NEPSetDS(NEP nep,DS ds)
491: {
495:   PetscObjectReference((PetscObject)ds);
496:   DSDestroy(&nep->ds);
497:   nep->ds = ds;
498:   return 0;
499: }

501: /*@
502:    NEPGetDS - Obtain the direct solver object associated to the
503:    nonlinear eigensolver object.

505:    Not Collective

507:    Input Parameters:
508: .  nep - eigensolver context obtained from NEPCreate()

510:    Output Parameter:
511: .  ds - direct solver context

513:    Level: advanced

515: .seealso: NEPSetDS()
516: @*/
517: PetscErrorCode NEPGetDS(NEP nep,DS *ds)
518: {
521:   if (!nep->ds) {
522:     DSCreate(PetscObjectComm((PetscObject)nep),&nep->ds);
523:     PetscObjectIncrementTabLevel((PetscObject)nep->ds,(PetscObject)nep,0);
524:     PetscObjectSetOptions((PetscObject)nep->ds,((PetscObject)nep)->options);
525:   }
526:   *ds = nep->ds;
527:   return 0;
528: }

530: /*@
531:    NEPRefineGetKSP - Obtain the ksp object used by the eigensolver
532:    object in the refinement phase.

534:    Not Collective

536:    Input Parameters:
537: .  nep - eigensolver context obtained from NEPCreate()

539:    Output Parameter:
540: .  ksp - ksp context

542:    Level: advanced

544: .seealso: NEPSetRefine()
545: @*/
546: PetscErrorCode NEPRefineGetKSP(NEP nep,KSP *ksp)
547: {
548:   MPI_Comm       comm;

552:   if (!nep->refineksp) {
553:     if (nep->npart>1) {
554:       /* Split in subcomunicators */
555:       PetscSubcommCreate(PetscObjectComm((PetscObject)nep),&nep->refinesubc);
556:       PetscSubcommSetNumber(nep->refinesubc,nep->npart);
557:       PetscSubcommSetType(nep->refinesubc,PETSC_SUBCOMM_CONTIGUOUS);
558:       PetscSubcommGetChild(nep->refinesubc,&comm);
559:     } else PetscObjectGetComm((PetscObject)nep,&comm);
560:     KSPCreate(comm,&nep->refineksp);
561:     PetscObjectIncrementTabLevel((PetscObject)nep->refineksp,(PetscObject)nep,0);
562:     PetscObjectSetOptions((PetscObject)nep->refineksp,((PetscObject)nep)->options);
563:     KSPSetOptionsPrefix(*ksp,((PetscObject)nep)->prefix);
564:     KSPAppendOptionsPrefix(*ksp,"nep_refine_");
565:     KSPSetTolerances(nep->refineksp,SlepcDefaultTol(nep->rtol),PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
566:   }
567:   *ksp = nep->refineksp;
568:   return 0;
569: }

571: /*@
572:    NEPSetTarget - Sets the value of the target.

574:    Logically Collective on nep

576:    Input Parameters:
577: +  nep    - eigensolver context
578: -  target - the value of the target

580:    Options Database Key:
581: .  -nep_target <scalar> - the value of the target

583:    Notes:
584:    The target is a scalar value used to determine the portion of the spectrum
585:    of interest. It is used in combination with NEPSetWhichEigenpairs().

587:    In the case of complex scalars, a complex value can be provided in the
588:    command line with [+/-][realnumber][+/-]realnumberi with no spaces, e.g.
589:    -nep_target 1.0+2.0i

591:    Level: intermediate

593: .seealso: NEPGetTarget(), NEPSetWhichEigenpairs()
594: @*/
595: PetscErrorCode NEPSetTarget(NEP nep,PetscScalar target)
596: {
599:   nep->target = target;
600:   return 0;
601: }

603: /*@
604:    NEPGetTarget - Gets the value of the target.

606:    Not Collective

608:    Input Parameter:
609: .  nep - eigensolver context

611:    Output Parameter:
612: .  target - the value of the target

614:    Note:
615:    If the target was not set by the user, then zero is returned.

617:    Level: intermediate

619: .seealso: NEPSetTarget()
620: @*/
621: PetscErrorCode NEPGetTarget(NEP nep,PetscScalar* target)
622: {
625:   *target = nep->target;
626:   return 0;
627: }

629: /*@C
630:    NEPSetFunction - Sets the function to compute the nonlinear Function T(lambda)
631:    as well as the location to store the matrix.

633:    Logically Collective on nep

635:    Input Parameters:
636: +  nep - the NEP context
637: .  A   - Function matrix
638: .  B   - preconditioner matrix (usually same as A)
639: .  fun - Function evaluation routine (if NULL then NEP retains any
640:          previously set value)
641: -  ctx - [optional] user-defined context for private data for the Function
642:          evaluation routine (may be NULL) (if NULL then NEP retains any
643:          previously set value)

645:    Calling Sequence of fun:
646: $   fun(NEP nep,PetscScalar lambda,Mat T,Mat P,void *ctx)

648: +  nep    - the NEP context
649: .  lambda - the scalar argument where T(.) must be evaluated
650: .  T      - matrix that will contain T(lambda)
651: .  P      - (optional) different matrix to build the preconditioner
652: -  ctx    - (optional) user-defined context, as set by NEPSetFunction()

654:    Level: beginner

656: .seealso: NEPGetFunction(), NEPSetJacobian()
657: @*/
658: PetscErrorCode NEPSetFunction(NEP nep,Mat A,Mat B,PetscErrorCode (*fun)(NEP,PetscScalar,Mat,Mat,void*),void *ctx)
659: {

666:   if (nep->state) NEPReset(nep);
667:   else if (nep->fui && nep->fui!=NEP_USER_INTERFACE_CALLBACK) NEPReset_Problem(nep);

669:   if (fun) nep->computefunction = fun;
670:   if (ctx) nep->functionctx     = ctx;
671:   if (A) {
672:     PetscObjectReference((PetscObject)A);
673:     MatDestroy(&nep->function);
674:     nep->function = A;
675:   }
676:   if (B) {
677:     PetscObjectReference((PetscObject)B);
678:     MatDestroy(&nep->function_pre);
679:     nep->function_pre = B;
680:   }
681:   nep->fui   = NEP_USER_INTERFACE_CALLBACK;
682:   nep->state = NEP_STATE_INITIAL;
683:   return 0;
684: }

686: /*@C
687:    NEPGetFunction - Returns the Function matrix and optionally the user
688:    provided context for evaluating the Function.

690:    Not Collective, but Mat object will be parallel if NEP object is

692:    Input Parameter:
693: .  nep - the nonlinear eigensolver context

695:    Output Parameters:
696: +  A   - location to stash Function matrix (or NULL)
697: .  B   - location to stash preconditioner matrix (or NULL)
698: .  fun - location to put Function function (or NULL)
699: -  ctx - location to stash Function context (or NULL)

701:    Level: advanced

703: .seealso: NEPSetFunction()
704: @*/
705: PetscErrorCode NEPGetFunction(NEP nep,Mat *A,Mat *B,PetscErrorCode (**fun)(NEP,PetscScalar,Mat,Mat,void*),void **ctx)
706: {
708:   NEPCheckCallback(nep,1);
709:   if (A)   *A   = nep->function;
710:   if (B)   *B   = nep->function_pre;
711:   if (fun) *fun = nep->computefunction;
712:   if (ctx) *ctx = nep->functionctx;
713:   return 0;
714: }

716: /*@C
717:    NEPSetJacobian - Sets the function to compute the Jacobian T'(lambda) as well
718:    as the location to store the matrix.

720:    Logically Collective on nep

722:    Input Parameters:
723: +  nep - the NEP context
724: .  A   - Jacobian matrix
725: .  jac - Jacobian evaluation routine (if NULL then NEP retains any
726:          previously set value)
727: -  ctx - [optional] user-defined context for private data for the Jacobian
728:          evaluation routine (may be NULL) (if NULL then NEP retains any
729:          previously set value)

731:    Calling Sequence of jac:
732: $   jac(NEP nep,PetscScalar lambda,Mat J,void *ctx)

734: +  nep    - the NEP context
735: .  lambda - the scalar argument where T'(.) must be evaluated
736: .  J      - matrix that will contain T'(lambda)
737: -  ctx    - (optional) user-defined context, as set by NEPSetJacobian()

739:    Level: beginner

741: .seealso: NEPSetFunction(), NEPGetJacobian()
742: @*/
743: PetscErrorCode NEPSetJacobian(NEP nep,Mat A,PetscErrorCode (*jac)(NEP,PetscScalar,Mat,void*),void *ctx)
744: {

749:   if (nep->state) NEPReset(nep);
750:   else if (nep->fui && nep->fui!=NEP_USER_INTERFACE_CALLBACK) NEPReset_Problem(nep);

752:   if (jac) nep->computejacobian = jac;
753:   if (ctx) nep->jacobianctx     = ctx;
754:   if (A) {
755:     PetscObjectReference((PetscObject)A);
756:     MatDestroy(&nep->jacobian);
757:     nep->jacobian = A;
758:   }
759:   nep->fui   = NEP_USER_INTERFACE_CALLBACK;
760:   nep->state = NEP_STATE_INITIAL;
761:   return 0;
762: }

764: /*@C
765:    NEPGetJacobian - Returns the Jacobian matrix and optionally the user
766:    provided routine and context for evaluating the Jacobian.

768:    Not Collective, but Mat object will be parallel if NEP object is

770:    Input Parameter:
771: .  nep - the nonlinear eigensolver context

773:    Output Parameters:
774: +  A   - location to stash Jacobian matrix (or NULL)
775: .  jac - location to put Jacobian function (or NULL)
776: -  ctx - location to stash Jacobian context (or NULL)

778:    Level: advanced

780: .seealso: NEPSetJacobian()
781: @*/
782: PetscErrorCode NEPGetJacobian(NEP nep,Mat *A,PetscErrorCode (**jac)(NEP,PetscScalar,Mat,void*),void **ctx)
783: {
785:   NEPCheckCallback(nep,1);
786:   if (A)   *A   = nep->jacobian;
787:   if (jac) *jac = nep->computejacobian;
788:   if (ctx) *ctx = nep->jacobianctx;
789:   return 0;
790: }

792: /*@
793:    NEPSetSplitOperator - Sets the operator of the nonlinear eigenvalue problem
794:    in split form.

796:    Collective on nep

798:    Input Parameters:
799: +  nep - the nonlinear eigensolver context
800: .  nt  - number of terms in the split form
801: .  A   - array of matrices
802: .  f   - array of functions
803: -  str - structure flag for matrices

805:    Notes:
806:    The nonlinear operator is written as T(lambda) = sum_i A_i*f_i(lambda),
807:    for i=1,...,n. The derivative T'(lambda) can be obtained using the
808:    derivatives of f_i.

810:    The structure flag provides information about A_i's nonzero pattern
811:    (see MatStructure enum). If all matrices have the same pattern, then
812:    use SAME_NONZERO_PATTERN. If the patterns are different but contained
813:    in the pattern of the first one, then use SUBSET_NONZERO_PATTERN. If
814:    patterns are known to be different, use DIFFERENT_NONZERO_PATTERN.
815:    If set to UNKNOWN_NONZERO_PATTERN, the patterns will be compared to
816:    determine if they are equal.

818:    This function must be called before NEPSetUp(). If it is called again
819:    after NEPSetUp() then the NEP object is reset.

821:    Level: beginner

823: .seealso: NEPGetSplitOperatorTerm(), NEPGetSplitOperatorInfo(), NEPSetSplitPreconditioner()
824: @*/
825: PetscErrorCode NEPSetSplitOperator(NEP nep,PetscInt nt,Mat A[],FN f[],MatStructure str)
826: {
827:   PetscInt       i,n=0,m,m0=0,mloc,nloc,mloc0=0;


836:   for (i=0;i<nt;i++) {
841:     MatGetSize(A[i],&m,&n);
842:     MatGetLocalSize(A[i],&mloc,&nloc);
845:     if (!i) { m0 = m; mloc0 = mloc; }
848:     PetscObjectReference((PetscObject)A[i]);
849:     PetscObjectReference((PetscObject)f[i]);
850:   }

852:   if (nep->state && (n!=nep->n || nloc!=nep->nloc)) NEPReset(nep);
853:   else NEPReset_Problem(nep);

855:   /* allocate space and copy matrices and functions */
856:   PetscMalloc1(nt,&nep->A);
857:   for (i=0;i<nt;i++) nep->A[i] = A[i];
858:   PetscMalloc1(nt,&nep->f);
859:   for (i=0;i<nt;i++) nep->f[i] = f[i];
860:   PetscCalloc1(nt,&nep->nrma);
861:   nep->nt    = nt;
862:   nep->mstr  = str;
863:   nep->fui   = NEP_USER_INTERFACE_SPLIT;
864:   nep->state = NEP_STATE_INITIAL;
865:   return 0;
866: }

868: /*@
869:    NEPGetSplitOperatorTerm - Gets the matrices and functions associated with
870:    the nonlinear operator in split form.

872:    Not collective, though parallel Mats and FNs are returned if the NEP is parallel

874:    Input Parameters:
875: +  nep - the nonlinear eigensolver context
876: -  k   - the index of the requested term (starting in 0)

878:    Output Parameters:
879: +  A - the matrix of the requested term
880: -  f - the function of the requested term

882:    Level: intermediate

884: .seealso: NEPSetSplitOperator(), NEPGetSplitOperatorInfo()
885: @*/
886: PetscErrorCode NEPGetSplitOperatorTerm(NEP nep,PetscInt k,Mat *A,FN *f)
887: {
890:   NEPCheckSplit(nep,1);
892:   if (A) *A = nep->A[k];
893:   if (f) *f = nep->f[k];
894:   return 0;
895: }

897: /*@
898:    NEPGetSplitOperatorInfo - Returns the number of terms of the split form of
899:    the nonlinear operator, as well as the structure flag for matrices.

901:    Not collective

903:    Input Parameter:
904: .  nep - the nonlinear eigensolver context

906:    Output Parameters:
907: +  n   - the number of terms passed in NEPSetSplitOperator()
908: -  str - the matrix structure flag passed in NEPSetSplitOperator()

910:    Level: intermediate

912: .seealso: NEPSetSplitOperator(), NEPGetSplitOperatorTerm()
913: @*/
914: PetscErrorCode NEPGetSplitOperatorInfo(NEP nep,PetscInt *n,MatStructure *str)
915: {
917:   NEPCheckSplit(nep,1);
918:   if (n)   *n = nep->nt;
919:   if (str) *str = nep->mstr;
920:   return 0;
921: }

923: /*@
924:    NEPSetSplitPreconditioner - Sets an operator in split form from which
925:    to build the preconditioner to be used when solving the nonlinear
926:    eigenvalue problem in split form.

928:    Collective on nep

930:    Input Parameters:
931: +  nep  - the nonlinear eigensolver context
932: .  ntp  - number of terms in the split preconditioner
933: .  P    - array of matrices
934: -  strp - structure flag for matrices

936:    Notes:
937:    The matrix for the preconditioner is expressed as P(lambda) =
938:    sum_i P_i*f_i(lambda), for i=1,...,n, where the f_i functions
939:    are the same as in NEPSetSplitOperator(). It is not necessary to call
940:    this function. If it is not invoked, then the preconditioner is
941:    built from T(lambda), i.e., both matrices and functions passed in
942:    NEPSetSplitOperator().

944:    The structure flag provides information about P_i's nonzero pattern
945:    in the same way as in NEPSetSplitOperator().

947:    If the functions defining the preconditioner operator were different
948:    from the ones given in NEPSetSplitOperator(), then the split form
949:    cannot be used. Use the callback interface instead.

951:    Use ntp=0 to reset a previously set split preconditioner.

953:    Level: advanced

955: .seealso: NEPGetSplitPreconditionerTerm(), NEPGetSplitPreconditionerInfo(), NEPSetSplitOperator()
956: @*/
957: PetscErrorCode NEPSetSplitPreconditioner(NEP nep,PetscInt ntp,Mat P[],MatStructure strp)
958: {
959:   PetscInt       i,n=0,m,m0=0,mloc,nloc,mloc0=0;


969:   for (i=0;i<ntp;i++) {
972:     MatGetSize(P[i],&m,&n);
973:     MatGetLocalSize(P[i],&mloc,&nloc);
976:     if (!i) { m0 = m; mloc0 = mloc; }
979:     PetscObjectReference((PetscObject)P[i]);
980:   }

983:   if (nep->P) MatDestroyMatrices(nep->nt,&nep->P);

985:   /* allocate space and copy matrices */
986:   if (ntp) {
987:     PetscMalloc1(ntp,&nep->P);
988:     for (i=0;i<ntp;i++) nep->P[i] = P[i];
989:   }
990:   nep->mstrp = strp;
991:   nep->state = NEP_STATE_INITIAL;
992:   return 0;
993: }

995: /*@
996:    NEPGetSplitPreconditionerTerm - Gets the matrices associated with
997:    the split preconditioner.

999:    Not collective, though parallel Mats are returned if the NEP is parallel

1001:    Input Parameters:
1002: +  nep - the nonlinear eigensolver context
1003: -  k   - the index of the requested term (starting in 0)

1005:    Output Parameter:
1006: .  P  - the matrix of the requested term

1008:    Level: advanced

1010: .seealso: NEPSetSplitPreconditioner(), NEPGetSplitPreconditionerInfo()
1011: @*/
1012: PetscErrorCode NEPGetSplitPreconditionerTerm(NEP nep,PetscInt k,Mat *P)
1013: {
1017:   NEPCheckSplit(nep,1);
1020:   *P = nep->P[k];
1021:   return 0;
1022: }

1024: /*@
1025:    NEPGetSplitPreconditionerInfo - Returns the number of terms of the split
1026:    preconditioner, as well as the structure flag for matrices.

1028:    Not collective

1030:    Input Parameter:
1031: .  nep - the nonlinear eigensolver context

1033:    Output Parameters:
1034: +  n    - the number of terms passed in NEPSetSplitPreconditioner()
1035: -  strp - the matrix structure flag passed in NEPSetSplitPreconditioner()

1037:    Level: advanced

1039: .seealso: NEPSetSplitPreconditioner(), NEPGetSplitPreconditionerTerm()
1040: @*/
1041: PetscErrorCode NEPGetSplitPreconditionerInfo(NEP nep,PetscInt *n,MatStructure *strp)
1042: {
1044:   NEPCheckSplit(nep,1);
1045:   if (n)    *n    = nep->P? nep->nt: 0;
1046:   if (strp) *strp = nep->mstrp;
1047:   return 0;
1048: }