Actual source code: pepbasic.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: Basic PEP routines
12: */
14: #include <slepc/private/pepimpl.h>
16: /* Logging support */
17: PetscClassId PEP_CLASSID = 0;
18: PetscLogEvent PEP_SetUp = 0,PEP_Solve = 0,PEP_Refine = 0,PEP_CISS_SVD = 0;
20: /* List of registered PEP routines */
21: PetscFunctionList PEPList = NULL;
22: PetscBool PEPRegisterAllCalled = PETSC_FALSE;
24: /* List of registered PEP monitors */
25: PetscFunctionList PEPMonitorList = NULL;
26: PetscFunctionList PEPMonitorCreateList = NULL;
27: PetscFunctionList PEPMonitorDestroyList = NULL;
28: PetscBool PEPMonitorRegisterAllCalled = PETSC_FALSE;
30: /*@
31: PEPCreate - Creates the `PEP` context.
33: Collective
35: Input Parameter:
36: . comm - MPI communicator
38: Output Parameter:
39: . outpep - location to put the `PEP` context
41: Note:
42: The default `PEP` type is `PEPTOAR`.
44: Level: beginner
46: .seealso: [](ch:pep), `PEPSetUp()`, `PEPSolve()`, `PEPDestroy()`, `PEP`
47: @*/
48: PetscErrorCode PEPCreate(MPI_Comm comm,PEP *outpep)
49: {
50: PEP pep;
52: PetscFunctionBegin;
53: PetscAssertPointer(outpep,2);
54: PetscCall(PEPInitializePackage());
55: PetscCall(SlepcHeaderCreate(pep,PEP_CLASSID,"PEP","Polynomial Eigenvalue Problem","PEP",comm,PEPDestroy,PEPView));
57: pep->max_it = PETSC_DETERMINE;
58: pep->nev = 1;
59: pep->ncv = PETSC_DETERMINE;
60: pep->mpd = PETSC_DETERMINE;
61: pep->nini = 0;
62: pep->target = 0.0;
63: pep->tol = PETSC_DETERMINE;
64: pep->conv = PEP_CONV_REL;
65: pep->stop = PEP_STOP_BASIC;
66: pep->which = (PEPWhich)0;
67: pep->basis = PEP_BASIS_MONOMIAL;
68: pep->problem_type = (PEPProblemType)0;
69: pep->scale = PEP_SCALE_NONE;
70: pep->sfactor = 1.0;
71: pep->dsfactor = 1.0;
72: pep->sits = 5;
73: pep->slambda = 1.0;
74: pep->refine = PEP_REFINE_NONE;
75: pep->npart = 1;
76: pep->rtol = PETSC_DETERMINE;
77: pep->rits = PETSC_DETERMINE;
78: pep->scheme = (PEPRefineScheme)0;
79: pep->extract = (PEPExtract)0;
80: pep->trackall = PETSC_FALSE;
82: pep->converged = PEPConvergedRelative;
83: pep->convergeduser = NULL;
84: pep->convergeddestroy= NULL;
85: pep->stopping = PEPStoppingBasic;
86: pep->stoppinguser = NULL;
87: pep->stoppingdestroy = NULL;
88: pep->convergedctx = NULL;
89: pep->stoppingctx = NULL;
90: pep->numbermonitors = 0;
92: pep->st = NULL;
93: pep->ds = NULL;
94: pep->V = NULL;
95: pep->rg = NULL;
96: pep->A = NULL;
97: pep->nmat = 0;
98: pep->Dl = NULL;
99: pep->Dr = NULL;
100: pep->IS = NULL;
101: pep->eigr = NULL;
102: pep->eigi = NULL;
103: pep->errest = NULL;
104: pep->perm = NULL;
105: pep->pbc = NULL;
106: pep->solvematcoeffs = NULL;
107: pep->nwork = 0;
108: pep->work = NULL;
109: pep->refineksp = NULL;
110: pep->refinesubc = NULL;
111: pep->data = NULL;
113: pep->state = PEP_STATE_INITIAL;
114: pep->nconv = 0;
115: pep->its = 0;
116: pep->n = 0;
117: pep->nloc = 0;
118: pep->nrma = NULL;
119: pep->sfactor_set = PETSC_FALSE;
120: pep->lineariz = PETSC_FALSE;
121: pep->reason = PEP_CONVERGED_ITERATING;
123: PetscCall(PetscNew(&pep->sc));
124: *outpep = pep;
125: PetscFunctionReturn(PETSC_SUCCESS);
126: }
128: /*@
129: PEPSetType - Selects the particular solver to be used in the `PEP` object.
131: Logically Collective
133: Input Parameters:
134: + pep - the polynomial eigensolver context
135: - type - a known method
137: Options Database Key:
138: . -pep_type \<type\> - sets the method; use `-help` for a list of available methods
140: Notes:
141: See `PEPType` for available methods. The default is `PEPTOAR`.
143: Normally, it is best to use the `PEPSetFromOptions()` command and
144: then set the `PEP` type from the options database rather than by using
145: this routine. Using the options database provides the user with
146: maximum flexibility in evaluating the different available methods.
147: The `PEPSetType()` routine is provided for those situations where it
148: is necessary to set the iterative solver independently of the command
149: line or options database.
151: Level: intermediate
153: .seealso: [](ch:pep), `PEPType`
154: @*/
155: PetscErrorCode PEPSetType(PEP pep,PEPType type)
156: {
157: PetscErrorCode (*r)(PEP);
158: PetscBool match;
160: PetscFunctionBegin;
162: PetscAssertPointer(type,2);
164: PetscCall(PetscObjectTypeCompare((PetscObject)pep,type,&match));
165: if (match) PetscFunctionReturn(PETSC_SUCCESS);
167: PetscCall(PetscFunctionListFind(PEPList,type,&r));
168: PetscCheck(r,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_UNKNOWN_TYPE,"Unknown PEP type given: %s",type);
170: PetscTryTypeMethod(pep,destroy);
171: PetscCall(PetscMemzero(pep->ops,sizeof(struct _PEPOps)));
173: pep->state = PEP_STATE_INITIAL;
174: PetscCall(PetscObjectChangeTypeName((PetscObject)pep,type));
175: PetscCall((*r)(pep));
176: PetscFunctionReturn(PETSC_SUCCESS);
177: }
179: /*@
180: PEPGetType - Gets the `PEP` type as a string from the `PEP` object.
182: Not Collective
184: Input Parameter:
185: . pep - the polynomial eigensolver context
187: Output Parameter:
188: . type - name of `PEP` method
190: Level: intermediate
192: .seealso: [](ch:pep), `PEPSetType()`
193: @*/
194: PetscErrorCode PEPGetType(PEP pep,PEPType *type)
195: {
196: PetscFunctionBegin;
198: PetscAssertPointer(type,2);
199: *type = ((PetscObject)pep)->type_name;
200: PetscFunctionReturn(PETSC_SUCCESS);
201: }
203: /*@C
204: PEPRegister - Adds a method to the polynomial eigenproblem solver package.
206: Not Collective
208: Input Parameters:
209: + name - name of a new user-defined solver
210: - function - routine to create the solver context
212: Note:
213: `PEPRegister()` may be called multiple times to add several user-defined solvers.
215: Example Usage:
216: .vb
217: PEPRegister("my_solver",MySolverCreate);
218: .ve
220: Then, your solver can be chosen with the procedural interface via
221: .vb
222: PEPSetType(pep,"my_solver")
223: .ve
224: or at runtime via the option `-pep_type my_solver`.
226: Level: advanced
228: .seealso: [](ch:pep), `PEPRegisterAll()`
229: @*/
230: PetscErrorCode PEPRegister(const char *name,PetscErrorCode (*function)(PEP))
231: {
232: PetscFunctionBegin;
233: PetscCall(PEPInitializePackage());
234: PetscCall(PetscFunctionListAdd(&PEPList,name,function));
235: PetscFunctionReturn(PETSC_SUCCESS);
236: }
238: /*@C
239: PEPMonitorRegister - Registers a `PEP` monitor routine that may be accessed with
240: `PEPMonitorSetFromOptions()`.
242: Not Collective
244: Input Parameters:
245: + name - name of a new monitor routine
246: . vtype - a `PetscViewerType` for the output
247: . format - a `PetscViewerFormat` for the output
248: . monitor - monitor routine, see `PEPMonitorRegisterFn`
249: . create - creation routine, or `NULL`
250: - destroy - destruction routine, or `NULL`
252: Notes:
253: `PEPMonitorRegister()` may be called multiple times to add several user-defined monitors.
255: The calling sequence for the given function matches the calling sequence of `PEPMonitorFn`
256: functions passed to `PEPMonitorSet()` with the additional requirement that its final argument
257: be a `PetscViewerAndFormat`.
259: Example Usage:
260: .vb
261: PEPMonitorRegister("my_monitor",PETSCVIEWERASCII,PETSC_VIEWER_ASCII_INFO_DETAIL,MyMonitor,NULL,NULL);
262: .ve
264: Then, your monitor can be chosen with the procedural interface via
265: .vb
266: PEPMonitorSetFromOptions(pep,"-pep_monitor_my_monitor","my_monitor",NULL);
267: .ve
268: or at runtime via the option `-pep_monitor_my_monitor`.
270: Level: advanced
272: .seealso: [](ch:pep), `PEPMonitorSet()`, `PEPMonitorRegisterAll()`, `PEPMonitorSetFromOptions()`
273: @*/
274: PetscErrorCode PEPMonitorRegister(const char name[],PetscViewerType vtype,PetscViewerFormat format,PEPMonitorRegisterFn *monitor,PEPMonitorRegisterCreateFn *create,PEPMonitorRegisterDestroyFn *destroy)
275: {
276: char key[PETSC_MAX_PATH_LEN];
278: PetscFunctionBegin;
279: PetscCall(PEPInitializePackage());
280: PetscCall(SlepcMonitorMakeKey_Internal(name,vtype,format,key));
281: PetscCall(PetscFunctionListAdd(&PEPMonitorList,key,monitor));
282: if (create) PetscCall(PetscFunctionListAdd(&PEPMonitorCreateList,key,create));
283: if (destroy) PetscCall(PetscFunctionListAdd(&PEPMonitorDestroyList,key,destroy));
284: PetscFunctionReturn(PETSC_SUCCESS);
285: }
287: /*@
288: PEPReset - Resets the `PEP` context to the initial state (prior to setup)
289: and destroys any allocated `Vec`s and `Mat`s.
291: Collective
293: Input Parameter:
294: . pep - the polynomial eigensolver context
296: Level: advanced
298: .seealso: [](ch:pep), `PEPDestroy()`
299: @*/
300: PetscErrorCode PEPReset(PEP pep)
301: {
302: PetscFunctionBegin;
304: if (!pep) PetscFunctionReturn(PETSC_SUCCESS);
305: PetscTryTypeMethod(pep,reset);
306: if (pep->st) PetscCall(STReset(pep->st));
307: if (pep->refineksp) PetscCall(KSPReset(pep->refineksp));
308: if (pep->nmat) {
309: PetscCall(MatDestroyMatrices(pep->nmat,&pep->A));
310: PetscCall(PetscFree2(pep->pbc,pep->nrma));
311: PetscCall(PetscFree(pep->solvematcoeffs));
312: pep->nmat = 0;
313: }
314: PetscCall(VecDestroy(&pep->Dl));
315: PetscCall(VecDestroy(&pep->Dr));
316: PetscCall(BVDestroy(&pep->V));
317: PetscCall(VecDestroyVecs(pep->nwork,&pep->work));
318: pep->nwork = 0;
319: pep->state = PEP_STATE_INITIAL;
320: PetscFunctionReturn(PETSC_SUCCESS);
321: }
323: /*@
324: PEPDestroy - Destroys the `PEP` context.
326: Collective
328: Input Parameter:
329: . pep - the polynomial eigensolver context
331: Level: beginner
333: .seealso: [](ch:pep), `PEPCreate()`, `PEPSetUp()`, `PEPSolve()`
334: @*/
335: PetscErrorCode PEPDestroy(PEP *pep)
336: {
337: PetscFunctionBegin;
338: if (!*pep) PetscFunctionReturn(PETSC_SUCCESS);
340: if (--((PetscObject)*pep)->refct > 0) { *pep = NULL; PetscFunctionReturn(PETSC_SUCCESS); }
341: PetscCall(PEPReset(*pep));
342: PetscTryTypeMethod(*pep,destroy);
343: if ((*pep)->eigr) PetscCall(PetscFree4((*pep)->eigr,(*pep)->eigi,(*pep)->errest,(*pep)->perm));
344: PetscCall(STDestroy(&(*pep)->st));
345: PetscCall(RGDestroy(&(*pep)->rg));
346: PetscCall(DSDestroy(&(*pep)->ds));
347: PetscCall(KSPDestroy(&(*pep)->refineksp));
348: PetscCall(PetscSubcommDestroy(&(*pep)->refinesubc));
349: PetscCall(PetscFree((*pep)->sc));
350: /* just in case the initial vectors have not been used */
351: PetscCall(SlepcBasisDestroy_Private(&(*pep)->nini,&(*pep)->IS));
352: if ((*pep)->convergeddestroy) PetscCall((*(*pep)->convergeddestroy)(&(*pep)->convergedctx));
353: if ((*pep)->stoppingdestroy) PetscCall((*(*pep)->stoppingdestroy)(&(*pep)->stoppingctx));
354: PetscCall(PEPMonitorCancel(*pep));
355: PetscCall(PetscHeaderDestroy(pep));
356: PetscFunctionReturn(PETSC_SUCCESS);
357: }
359: /*@
360: PEPSetBV - Associates a basis vectors object to the polynomial eigensolver.
362: Collective
364: Input Parameters:
365: + pep - the polynomial eigensolver context
366: - bv - the basis vectors object
368: Note:
369: Use `PEPGetBV()` to retrieve the basis vectors context (for example,
370: to free it at the end of the computations).
372: Level: advanced
374: .seealso: [](ch:pep), `PEPGetBV()`
375: @*/
376: PetscErrorCode PEPSetBV(PEP pep,BV bv)
377: {
378: PetscFunctionBegin;
381: PetscCheckSameComm(pep,1,bv,2);
382: PetscCall(PetscObjectReference((PetscObject)bv));
383: PetscCall(BVDestroy(&pep->V));
384: pep->V = bv;
385: PetscFunctionReturn(PETSC_SUCCESS);
386: }
388: /*@
389: PEPGetBV - Obtain the basis vectors object associated to the polynomial
390: eigensolver object.
392: Not Collective
394: Input Parameter:
395: . pep - the polynomial eigensolver context
397: Output Parameter:
398: . bv - basis vectors context
400: Level: advanced
402: .seealso: [](ch:pep), `PEPSetBV()`
403: @*/
404: PetscErrorCode PEPGetBV(PEP pep,BV *bv)
405: {
406: PetscFunctionBegin;
408: PetscAssertPointer(bv,2);
409: if (!pep->V) {
410: PetscCall(BVCreate(PetscObjectComm((PetscObject)pep),&pep->V));
411: PetscCall(PetscObjectIncrementTabLevel((PetscObject)pep->V,(PetscObject)pep,0));
412: PetscCall(PetscObjectSetOptions((PetscObject)pep->V,((PetscObject)pep)->options));
413: }
414: *bv = pep->V;
415: PetscFunctionReturn(PETSC_SUCCESS);
416: }
418: /*@
419: PEPSetRG - Associates a region object to the polynomial eigensolver.
421: Collective
423: Input Parameters:
424: + pep - the polynomial eigensolver context
425: - rg - the region object
427: Note:
428: Use `PEPGetRG()` to retrieve the region context (for example,
429: to free it at the end of the computations).
431: Level: advanced
433: .seealso: [](ch:pep), `PEPGetRG()`
434: @*/
435: PetscErrorCode PEPSetRG(PEP pep,RG rg)
436: {
437: PetscFunctionBegin;
439: if (rg) {
441: PetscCheckSameComm(pep,1,rg,2);
442: }
443: PetscCall(PetscObjectReference((PetscObject)rg));
444: PetscCall(RGDestroy(&pep->rg));
445: pep->rg = rg;
446: PetscFunctionReturn(PETSC_SUCCESS);
447: }
449: /*@
450: PEPGetRG - Obtain the region object associated to the
451: polynomial eigensolver object.
453: Not Collective
455: Input Parameter:
456: . pep - the polynomial eigensolver context
458: Output Parameter:
459: . rg - region context
461: Level: advanced
463: .seealso: [](ch:pep), `PEPSetRG()`
464: @*/
465: PetscErrorCode PEPGetRG(PEP pep,RG *rg)
466: {
467: PetscFunctionBegin;
469: PetscAssertPointer(rg,2);
470: if (!pep->rg) {
471: PetscCall(RGCreate(PetscObjectComm((PetscObject)pep),&pep->rg));
472: PetscCall(PetscObjectIncrementTabLevel((PetscObject)pep->rg,(PetscObject)pep,0));
473: PetscCall(PetscObjectSetOptions((PetscObject)pep->rg,((PetscObject)pep)->options));
474: }
475: *rg = pep->rg;
476: PetscFunctionReturn(PETSC_SUCCESS);
477: }
479: /*@
480: PEPSetDS - Associates a direct solver object to the polynomial eigensolver.
482: Collective
484: Input Parameters:
485: + pep - the polynomial eigensolver context
486: - ds - the direct solver object
488: Note:
489: Use `PEPGetDS()` to retrieve the direct solver context (for example,
490: to free it at the end of the computations).
492: Level: advanced
494: .seealso: [](ch:pep), `PEPGetDS()`
495: @*/
496: PetscErrorCode PEPSetDS(PEP pep,DS ds)
497: {
498: PetscFunctionBegin;
501: PetscCheckSameComm(pep,1,ds,2);
502: PetscCall(PetscObjectReference((PetscObject)ds));
503: PetscCall(DSDestroy(&pep->ds));
504: pep->ds = ds;
505: PetscFunctionReturn(PETSC_SUCCESS);
506: }
508: /*@
509: PEPGetDS - Obtain the direct solver object associated to the
510: polynomial eigensolver object.
512: Not Collective
514: Input Parameter:
515: . pep - the polynomial eigensolver context
517: Output Parameter:
518: . ds - direct solver context
520: Level: advanced
522: .seealso: [](ch:pep), `PEPSetDS()`
523: @*/
524: PetscErrorCode PEPGetDS(PEP pep,DS *ds)
525: {
526: PetscFunctionBegin;
528: PetscAssertPointer(ds,2);
529: if (!pep->ds) {
530: PetscCall(DSCreate(PetscObjectComm((PetscObject)pep),&pep->ds));
531: PetscCall(PetscObjectIncrementTabLevel((PetscObject)pep->ds,(PetscObject)pep,0));
532: PetscCall(PetscObjectSetOptions((PetscObject)pep->ds,((PetscObject)pep)->options));
533: }
534: *ds = pep->ds;
535: PetscFunctionReturn(PETSC_SUCCESS);
536: }
538: /*@
539: PEPSetST - Associates a spectral transformation object to the eigensolver.
541: Collective
543: Input Parameters:
544: + pep - the polynomial eigensolver context
545: - st - the spectral transformation object
547: Note:
548: Use `PEPGetST()` to retrieve the spectral transformation context (for example,
549: to free it at the end of the computations).
551: Level: advanced
553: .seealso: [](ch:pep), `PEPGetST()`
554: @*/
555: PetscErrorCode PEPSetST(PEP pep,ST st)
556: {
557: PetscFunctionBegin;
560: PetscCheckSameComm(pep,1,st,2);
561: PetscCall(PetscObjectReference((PetscObject)st));
562: PetscCall(STDestroy(&pep->st));
563: pep->st = st;
564: PetscFunctionReturn(PETSC_SUCCESS);
565: }
567: /*@
568: PEPGetST - Obtain the spectral transformation (`ST`) object associated
569: to the eigensolver object.
571: Not Collective
573: Input Parameter:
574: . pep - the polynomial eigensolver context
576: Output Parameter:
577: . st - spectral transformation context
579: Level: intermediate
581: .seealso: [](ch:pep), `PEPSetST()`
582: @*/
583: PetscErrorCode PEPGetST(PEP pep,ST *st)
584: {
585: PetscFunctionBegin;
587: PetscAssertPointer(st,2);
588: if (!pep->st) {
589: PetscCall(STCreate(PetscObjectComm((PetscObject)pep),&pep->st));
590: PetscCall(PetscObjectIncrementTabLevel((PetscObject)pep->st,(PetscObject)pep,0));
591: PetscCall(PetscObjectSetOptions((PetscObject)pep->st,((PetscObject)pep)->options));
592: }
593: *st = pep->st;
594: PetscFunctionReturn(PETSC_SUCCESS);
595: }
597: /*@
598: PEPRefineGetKSP - Obtain the `KSP` object used by the eigensolver
599: object in the refinement phase.
601: Collective
603: Input Parameter:
604: . pep - the polynomial eigensolver context
606: Output Parameter:
607: . ksp - the linear solver context
609: Level: advanced
611: .seealso: [](ch:pep), `PEPSetRefine()`
612: @*/
613: PetscErrorCode PEPRefineGetKSP(PEP pep,KSP *ksp)
614: {
615: MPI_Comm comm;
617: PetscFunctionBegin;
619: PetscAssertPointer(ksp,2);
620: if (!pep->refineksp) {
621: if (pep->npart>1) {
622: /* Split in subcomunicators */
623: PetscCall(PetscSubcommCreate(PetscObjectComm((PetscObject)pep),&pep->refinesubc));
624: PetscCall(PetscSubcommSetNumber(pep->refinesubc,pep->npart));
625: PetscCall(PetscSubcommSetType(pep->refinesubc,PETSC_SUBCOMM_CONTIGUOUS));
626: PetscCall(PetscSubcommGetChild(pep->refinesubc,&comm));
627: } else PetscCall(PetscObjectGetComm((PetscObject)pep,&comm));
628: PetscCall(KSPCreate(comm,&pep->refineksp));
629: PetscCall(PetscObjectIncrementTabLevel((PetscObject)pep->refineksp,(PetscObject)pep,0));
630: PetscCall(PetscObjectSetOptions((PetscObject)pep->refineksp,((PetscObject)pep)->options));
631: PetscCall(KSPSetOptionsPrefix(*ksp,((PetscObject)pep)->prefix));
632: PetscCall(KSPAppendOptionsPrefix(*ksp,"pep_refine_"));
633: PetscCall(KSPSetTolerances(pep->refineksp,SlepcDefaultTol(pep->rtol),PETSC_CURRENT,PETSC_CURRENT,PETSC_CURRENT));
634: }
635: *ksp = pep->refineksp;
636: PetscFunctionReturn(PETSC_SUCCESS);
637: }
639: /*@
640: PEPSetTarget - Sets the value of the target.
642: Logically Collective
644: Input Parameters:
645: + pep - the polynomial eigensolver context
646: - target - the value of the target
648: Options Database Key:
649: . -pep_target \<target\> - the value of the target
651: Notes:
652: The target is a scalar value used to determine the portion of the spectrum
653: of interest. It is used in combination with `PEPSetWhichEigenpairs()`.
655: When PETSc is built with real scalars, it is not possible to specify a
656: complex target.
658: In the case of complex scalars, a complex value can be provided in the
659: command line with `[+/-][realnumber][+/-]realnumberi` with no spaces, e.g.
660: `-pep_target 1.0+2.0i`.
662: Level: intermediate
664: .seealso: [](ch:pep), `PEPGetTarget()`, `PEPSetWhichEigenpairs()`
665: @*/
666: PetscErrorCode PEPSetTarget(PEP pep,PetscScalar target)
667: {
668: PetscFunctionBegin;
671: pep->target = target;
672: if (!pep->st) PetscCall(PEPGetST(pep,&pep->st));
673: PetscCall(STSetDefaultShift(pep->st,target));
674: PetscFunctionReturn(PETSC_SUCCESS);
675: }
677: /*@
678: PEPGetTarget - Gets the value of the target.
680: Not Collective
682: Input Parameter:
683: . pep - the polynomial eigensolver context
685: Output Parameter:
686: . target - the value of the target
688: Note:
689: If the target was not set by the user, then zero is returned.
691: Level: intermediate
693: .seealso: [](ch:pep), `PEPSetTarget()`
694: @*/
695: PetscErrorCode PEPGetTarget(PEP pep,PetscScalar* target)
696: {
697: PetscFunctionBegin;
699: PetscAssertPointer(target,2);
700: *target = pep->target;
701: PetscFunctionReturn(PETSC_SUCCESS);
702: }
704: /*@
705: PEPSetInterval - Defines the computational interval for spectrum slicing.
707: Logically Collective
709: Input Parameters:
710: + pep - the polynomial eigensolver context
711: . inta - left end of the interval
712: - intb - right end of the interval
714: Options Database Key:
715: . -pep_interval <a,b> - set $[a,b]$ as the interval of interest
717: Notes:
718: Spectrum slicing is a technique employed for computing all eigenvalues of
719: symmetric eigenproblems in a given interval, see section [](#sec:qslice).
720: This function provides the interval to be considered. It must be used in
721: combination with `PEP_ALL`, see `PEPSetWhichEigenpairs()`. Note that in
722: polynomial eigenproblems spectrum slicing is implemented in `PEPSTOAR` only.
724: In the command-line option, two values must be provided. For an open interval,
725: one can give an infinite, e.g., `-pep_interval 1.0,inf` or `-pep_interval -inf,1.0`.
726: An open interval in the programmatic interface can be specified with
727: `PETSC_MAX_REAL` and -`PETSC_MAX_REAL`.
729: Level: intermediate
731: .seealso: [](ch:pep), [](#sec:qslice), `PEPGetInterval()`, `PEPSetWhichEigenpairs()`, `PEPSTOAR`
732: @*/
733: PetscErrorCode PEPSetInterval(PEP pep,PetscReal inta,PetscReal intb)
734: {
735: PetscFunctionBegin;
739: PetscCheck(inta<intb,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_WRONG,"Badly defined interval, must be inta<intb");
740: if (pep->inta != inta || pep->intb != intb) {
741: pep->inta = inta;
742: pep->intb = intb;
743: pep->state = PEP_STATE_INITIAL;
744: }
745: PetscFunctionReturn(PETSC_SUCCESS);
746: }
748: /*@
749: PEPGetInterval - Gets the computational interval for spectrum slicing.
751: Not Collective
753: Input Parameter:
754: . pep - the polynomial eigensolver context
756: Output Parameters:
757: + inta - left end of the interval
758: - intb - right end of the interval
760: Level: intermediate
762: Note:
763: If the interval was not set by the user, then zeros are returned.
765: .seealso: [](ch:pep), `PEPSetInterval()`
766: @*/
767: PetscErrorCode PEPGetInterval(PEP pep,PetscReal* inta,PetscReal* intb)
768: {
769: PetscFunctionBegin;
771: if (inta) *inta = pep->inta;
772: if (intb) *intb = pep->intb;
773: PetscFunctionReturn(PETSC_SUCCESS);
774: }