Actual source code: nepopts.c

slepc-3.20.1 2023-11-27
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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:    NEP routines related to options that can be set via the command-line
 12:    or procedurally
 13: */

 15: #include <slepc/private/nepimpl.h>
 16: #include <petscdraw.h>

 18: /*@C
 19:    NEPMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type
 20:    indicated by the user.

 22:    Collective

 24:    Input Parameters:
 25: +  nep      - the nonlinear eigensolver context
 26: .  opt      - the command line option for this monitor
 27: .  name     - the monitor type one is seeking
 28: .  ctx      - an optional user context for the monitor, or NULL
 29: -  trackall - whether this monitor tracks all eigenvalues or not

 31:    Level: developer

 33: .seealso: NEPMonitorSet(), NEPSetTrackAll()
 34: @*/
 35: PetscErrorCode NEPMonitorSetFromOptions(NEP nep,const char opt[],const char name[],void *ctx,PetscBool trackall)
 36: {
 37:   PetscErrorCode       (*mfunc)(NEP,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,void*);
 38:   PetscErrorCode       (*cfunc)(PetscViewer,PetscViewerFormat,void*,PetscViewerAndFormat**);
 39:   PetscErrorCode       (*dfunc)(PetscViewerAndFormat**);
 40:   PetscViewerAndFormat *vf;
 41:   PetscViewer          viewer;
 42:   PetscViewerFormat    format;
 43:   PetscViewerType      vtype;
 44:   char                 key[PETSC_MAX_PATH_LEN];
 45:   PetscBool            flg;

 47:   PetscFunctionBegin;
 48:   PetscCall(PetscOptionsGetViewer(PetscObjectComm((PetscObject)nep),((PetscObject)nep)->options,((PetscObject)nep)->prefix,opt,&viewer,&format,&flg));
 49:   if (!flg) PetscFunctionReturn(PETSC_SUCCESS);

 51:   PetscCall(PetscViewerGetType(viewer,&vtype));
 52:   PetscCall(SlepcMonitorMakeKey_Internal(name,vtype,format,key));
 53:   PetscCall(PetscFunctionListFind(NEPMonitorList,key,&mfunc));
 54:   PetscCheck(mfunc,PetscObjectComm((PetscObject)nep),PETSC_ERR_SUP,"Specified viewer and format not supported");
 55:   PetscCall(PetscFunctionListFind(NEPMonitorCreateList,key,&cfunc));
 56:   PetscCall(PetscFunctionListFind(NEPMonitorDestroyList,key,&dfunc));
 57:   if (!cfunc) cfunc = PetscViewerAndFormatCreate_Internal;
 58:   if (!dfunc) dfunc = PetscViewerAndFormatDestroy;

 60:   PetscCall((*cfunc)(viewer,format,ctx,&vf));
 61:   PetscCall(PetscObjectDereference((PetscObject)viewer));
 62:   PetscCall(NEPMonitorSet(nep,mfunc,vf,(PetscErrorCode(*)(void **))dfunc));
 63:   if (trackall) PetscCall(NEPSetTrackAll(nep,PETSC_TRUE));
 64:   PetscFunctionReturn(PETSC_SUCCESS);
 65: }

 67: /*@
 68:    NEPSetFromOptions - Sets NEP options from the options database.
 69:    This routine must be called before NEPSetUp() if the user is to be
 70:    allowed to set the solver type.

 72:    Collective

 74:    Input Parameters:
 75: .  nep - the nonlinear eigensolver context

 77:    Notes:
 78:    To see all options, run your program with the -help option.

 80:    Level: beginner

 82: .seealso: NEPSetOptionsPrefix()
 83: @*/
 84: PetscErrorCode NEPSetFromOptions(NEP nep)
 85: {
 86:   char            type[256];
 87:   PetscBool       set,flg,flg1,flg2,flg3,flg4,flg5,bval;
 88:   PetscReal       r;
 89:   PetscScalar     s;
 90:   PetscInt        i,j,k;
 91:   NEPRefine       refine;
 92:   NEPRefineScheme scheme;

 94:   PetscFunctionBegin;
 96:   PetscCall(NEPRegisterAll());
 97:   PetscObjectOptionsBegin((PetscObject)nep);
 98:     PetscCall(PetscOptionsFList("-nep_type","Nonlinear eigensolver method","NEPSetType",NEPList,(char*)(((PetscObject)nep)->type_name?((PetscObject)nep)->type_name:NEPRII),type,sizeof(type),&flg));
 99:     if (flg) PetscCall(NEPSetType(nep,type));
100:     else if (!((PetscObject)nep)->type_name) PetscCall(NEPSetType(nep,NEPRII));

102:     PetscCall(PetscOptionsBoolGroupBegin("-nep_general","General nonlinear eigenvalue problem","NEPSetProblemType",&flg));
103:     if (flg) PetscCall(NEPSetProblemType(nep,NEP_GENERAL));
104:     PetscCall(PetscOptionsBoolGroupEnd("-nep_rational","Rational eigenvalue problem","NEPSetProblemType",&flg));
105:     if (flg) PetscCall(NEPSetProblemType(nep,NEP_RATIONAL));

107:     refine = nep->refine;
108:     PetscCall(PetscOptionsEnum("-nep_refine","Iterative refinement method","NEPSetRefine",NEPRefineTypes,(PetscEnum)refine,(PetscEnum*)&refine,&flg1));
109:     i = nep->npart;
110:     PetscCall(PetscOptionsInt("-nep_refine_partitions","Number of partitions of the communicator for iterative refinement","NEPSetRefine",nep->npart,&i,&flg2));
111:     r = nep->rtol;
112:     PetscCall(PetscOptionsReal("-nep_refine_tol","Tolerance for iterative refinement","NEPSetRefine",nep->rtol==(PetscReal)PETSC_DEFAULT?SLEPC_DEFAULT_TOL/1000:nep->rtol,&r,&flg3));
113:     j = nep->rits;
114:     PetscCall(PetscOptionsInt("-nep_refine_its","Maximum number of iterations for iterative refinement","NEPSetRefine",nep->rits,&j,&flg4));
115:     scheme = nep->scheme;
116:     PetscCall(PetscOptionsEnum("-nep_refine_scheme","Scheme used for linear systems within iterative refinement","NEPSetRefine",NEPRefineSchemes,(PetscEnum)scheme,(PetscEnum*)&scheme,&flg5));
117:     if (flg1 || flg2 || flg3 || flg4 || flg5) PetscCall(NEPSetRefine(nep,refine,i,r,j,scheme));

119:     i = nep->max_it;
120:     PetscCall(PetscOptionsInt("-nep_max_it","Maximum number of iterations","NEPSetTolerances",nep->max_it,&i,&flg1));
121:     r = nep->tol;
122:     PetscCall(PetscOptionsReal("-nep_tol","Tolerance","NEPSetTolerances",SlepcDefaultTol(nep->tol),&r,&flg2));
123:     if (flg1 || flg2) PetscCall(NEPSetTolerances(nep,r,i));

125:     PetscCall(PetscOptionsBoolGroupBegin("-nep_conv_rel","Relative error convergence test","NEPSetConvergenceTest",&flg));
126:     if (flg) PetscCall(NEPSetConvergenceTest(nep,NEP_CONV_REL));
127:     PetscCall(PetscOptionsBoolGroup("-nep_conv_norm","Convergence test relative to the matrix norms","NEPSetConvergenceTest",&flg));
128:     if (flg) PetscCall(NEPSetConvergenceTest(nep,NEP_CONV_NORM));
129:     PetscCall(PetscOptionsBoolGroup("-nep_conv_abs","Absolute error convergence test","NEPSetConvergenceTest",&flg));
130:     if (flg) PetscCall(NEPSetConvergenceTest(nep,NEP_CONV_ABS));
131:     PetscCall(PetscOptionsBoolGroupEnd("-nep_conv_user","User-defined convergence test","NEPSetConvergenceTest",&flg));
132:     if (flg) PetscCall(NEPSetConvergenceTest(nep,NEP_CONV_USER));

134:     PetscCall(PetscOptionsBoolGroupBegin("-nep_stop_basic","Stop iteration if all eigenvalues converged or max_it reached","NEPSetStoppingTest",&flg));
135:     if (flg) PetscCall(NEPSetStoppingTest(nep,NEP_STOP_BASIC));
136:     PetscCall(PetscOptionsBoolGroupEnd("-nep_stop_user","User-defined stopping test","NEPSetStoppingTest",&flg));
137:     if (flg) PetscCall(NEPSetStoppingTest(nep,NEP_STOP_USER));

139:     i = nep->nev;
140:     PetscCall(PetscOptionsInt("-nep_nev","Number of eigenvalues to compute","NEPSetDimensions",nep->nev,&i,&flg1));
141:     j = nep->ncv;
142:     PetscCall(PetscOptionsInt("-nep_ncv","Number of basis vectors","NEPSetDimensions",nep->ncv,&j,&flg2));
143:     k = nep->mpd;
144:     PetscCall(PetscOptionsInt("-nep_mpd","Maximum dimension of projected problem","NEPSetDimensions",nep->mpd,&k,&flg3));
145:     if (flg1 || flg2 || flg3) PetscCall(NEPSetDimensions(nep,i,j,k));

147:     PetscCall(PetscOptionsBoolGroupBegin("-nep_largest_magnitude","Compute largest eigenvalues in magnitude","NEPSetWhichEigenpairs",&flg));
148:     if (flg) PetscCall(NEPSetWhichEigenpairs(nep,NEP_LARGEST_MAGNITUDE));
149:     PetscCall(PetscOptionsBoolGroup("-nep_smallest_magnitude","Compute smallest eigenvalues in magnitude","NEPSetWhichEigenpairs",&flg));
150:     if (flg) PetscCall(NEPSetWhichEigenpairs(nep,NEP_SMALLEST_MAGNITUDE));
151:     PetscCall(PetscOptionsBoolGroup("-nep_largest_real","Compute eigenvalues with largest real parts","NEPSetWhichEigenpairs",&flg));
152:     if (flg) PetscCall(NEPSetWhichEigenpairs(nep,NEP_LARGEST_REAL));
153:     PetscCall(PetscOptionsBoolGroup("-nep_smallest_real","Compute eigenvalues with smallest real parts","NEPSetWhichEigenpairs",&flg));
154:     if (flg) PetscCall(NEPSetWhichEigenpairs(nep,NEP_SMALLEST_REAL));
155:     PetscCall(PetscOptionsBoolGroup("-nep_largest_imaginary","Compute eigenvalues with largest imaginary parts","NEPSetWhichEigenpairs",&flg));
156:     if (flg) PetscCall(NEPSetWhichEigenpairs(nep,NEP_LARGEST_IMAGINARY));
157:     PetscCall(PetscOptionsBoolGroup("-nep_smallest_imaginary","Compute eigenvalues with smallest imaginary parts","NEPSetWhichEigenpairs",&flg));
158:     if (flg) PetscCall(NEPSetWhichEigenpairs(nep,NEP_SMALLEST_IMAGINARY));
159:     PetscCall(PetscOptionsBoolGroup("-nep_target_magnitude","Compute eigenvalues closest to target","NEPSetWhichEigenpairs",&flg));
160:     if (flg) PetscCall(NEPSetWhichEigenpairs(nep,NEP_TARGET_MAGNITUDE));
161:     PetscCall(PetscOptionsBoolGroup("-nep_target_real","Compute eigenvalues with real parts closest to target","NEPSetWhichEigenpairs",&flg));
162:     if (flg) PetscCall(NEPSetWhichEigenpairs(nep,NEP_TARGET_REAL));
163:     PetscCall(PetscOptionsBoolGroup("-nep_target_imaginary","Compute eigenvalues with imaginary parts closest to target","NEPSetWhichEigenpairs",&flg));
164:     if (flg) PetscCall(NEPSetWhichEigenpairs(nep,NEP_TARGET_IMAGINARY));
165:     PetscCall(PetscOptionsBoolGroupEnd("-nep_all","Compute all eigenvalues in a region","NEPSetWhichEigenpairs",&flg));
166:     if (flg) PetscCall(NEPSetWhichEigenpairs(nep,NEP_ALL));

168:     PetscCall(PetscOptionsScalar("-nep_target","Value of the target","NEPSetTarget",nep->target,&s,&flg));
169:     if (flg) {
170:       if (nep->which!=NEP_TARGET_REAL && nep->which!=NEP_TARGET_IMAGINARY) PetscCall(NEPSetWhichEigenpairs(nep,NEP_TARGET_MAGNITUDE));
171:       PetscCall(NEPSetTarget(nep,s));
172:     }

174:     PetscCall(PetscOptionsBool("-nep_two_sided","Use two-sided variant (to compute left eigenvectors)","NEPSetTwoSided",nep->twosided,&bval,&flg));
175:     if (flg) PetscCall(NEPSetTwoSided(nep,bval));

177:     /* -----------------------------------------------------------------------*/
178:     /*
179:       Cancels all monitors hardwired into code before call to NEPSetFromOptions()
180:     */
181:     PetscCall(PetscOptionsBool("-nep_monitor_cancel","Remove any hardwired monitor routines","NEPMonitorCancel",PETSC_FALSE,&flg,&set));
182:     if (set && flg) PetscCall(NEPMonitorCancel(nep));
183:     PetscCall(NEPMonitorSetFromOptions(nep,"-nep_monitor","first_approximation",NULL,PETSC_FALSE));
184:     PetscCall(NEPMonitorSetFromOptions(nep,"-nep_monitor_all","all_approximations",NULL,PETSC_TRUE));
185:     PetscCall(NEPMonitorSetFromOptions(nep,"-nep_monitor_conv","convergence_history",NULL,PETSC_FALSE));

187:     /* -----------------------------------------------------------------------*/
188:     PetscCall(PetscOptionsName("-nep_view","Print detailed information on solver used","NEPView",&set));
189:     PetscCall(PetscOptionsName("-nep_view_vectors","View computed eigenvectors","NEPVectorsView",&set));
190:     PetscCall(PetscOptionsName("-nep_view_values","View computed eigenvalues","NEPValuesView",&set));
191:     PetscCall(PetscOptionsName("-nep_converged_reason","Print reason for convergence, and number of iterations","NEPConvergedReasonView",&set));
192:     PetscCall(PetscOptionsName("-nep_error_absolute","Print absolute errors of each eigenpair","NEPErrorView",&set));
193:     PetscCall(PetscOptionsName("-nep_error_relative","Print relative errors of each eigenpair","NEPErrorView",&set));

195:     PetscTryTypeMethod(nep,setfromoptions,PetscOptionsObject);
196:     PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)nep,PetscOptionsObject));
197:   PetscOptionsEnd();

199:   if (!nep->V) PetscCall(NEPGetBV(nep,&nep->V));
200:   PetscCall(BVSetFromOptions(nep->V));
201:   if (!nep->rg) PetscCall(NEPGetRG(nep,&nep->rg));
202:   PetscCall(RGSetFromOptions(nep->rg));
203:   if (nep->useds) {
204:     if (!nep->ds) PetscCall(NEPGetDS(nep,&nep->ds));
205:     PetscCall(NEPSetDSType(nep));
206:     PetscCall(DSSetFromOptions(nep->ds));
207:   }
208:   if (!nep->refineksp) PetscCall(NEPRefineGetKSP(nep,&nep->refineksp));
209:   PetscCall(KSPSetFromOptions(nep->refineksp));
210:   if (nep->fui==NEP_USER_INTERFACE_SPLIT) for (i=0;i<nep->nt;i++) PetscCall(FNSetFromOptions(nep->f[i]));
211:   PetscFunctionReturn(PETSC_SUCCESS);
212: }

214: /*@C
215:    NEPGetTolerances - Gets the tolerance and maximum iteration count used
216:    by the NEP convergence tests.

218:    Not Collective

220:    Input Parameter:
221: .  nep - the nonlinear eigensolver context

223:    Output Parameters:
224: +  tol - the convergence tolerance
225: -  maxits - maximum number of iterations

227:    Notes:
228:    The user can specify NULL for any parameter that is not needed.

230:    Level: intermediate

232: .seealso: NEPSetTolerances()
233: @*/
234: PetscErrorCode NEPGetTolerances(NEP nep,PetscReal *tol,PetscInt *maxits)
235: {
236:   PetscFunctionBegin;
238:   if (tol)    *tol    = nep->tol;
239:   if (maxits) *maxits = nep->max_it;
240:   PetscFunctionReturn(PETSC_SUCCESS);
241: }

243: /*@
244:    NEPSetTolerances - Sets the tolerance and maximum iteration count used
245:    by the NEP convergence tests.

247:    Logically Collective

249:    Input Parameters:
250: +  nep    - the nonlinear eigensolver context
251: .  tol    - the convergence tolerance
252: -  maxits - maximum number of iterations to use

254:    Options Database Keys:
255: +  -nep_tol <tol> - Sets the convergence tolerance
256: -  -nep_max_it <maxits> - Sets the maximum number of iterations allowed

258:    Notes:
259:    Use PETSC_DEFAULT for either argument to assign a reasonably good value.

261:    Level: intermediate

263: .seealso: NEPGetTolerances()
264: @*/
265: PetscErrorCode NEPSetTolerances(NEP nep,PetscReal tol,PetscInt maxits)
266: {
267:   PetscFunctionBegin;
271:   if (tol == (PetscReal)PETSC_DEFAULT) {
272:     nep->tol   = PETSC_DEFAULT;
273:     nep->state = NEP_STATE_INITIAL;
274:   } else {
275:     PetscCheck(tol>0.0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
276:     nep->tol = tol;
277:   }
278:   if (maxits == PETSC_DEFAULT || maxits == PETSC_DECIDE) {
279:     nep->max_it = PETSC_DEFAULT;
280:     nep->state  = NEP_STATE_INITIAL;
281:   } else {
282:     PetscCheck(maxits>0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
283:     nep->max_it = maxits;
284:   }
285:   PetscFunctionReturn(PETSC_SUCCESS);
286: }

288: /*@C
289:    NEPGetDimensions - Gets the number of eigenvalues to compute
290:    and the dimension of the subspace.

292:    Not Collective

294:    Input Parameter:
295: .  nep - the nonlinear eigensolver context

297:    Output Parameters:
298: +  nev - number of eigenvalues to compute
299: .  ncv - the maximum dimension of the subspace to be used by the solver
300: -  mpd - the maximum dimension allowed for the projected problem

302:    Notes:
303:    The user can specify NULL for any parameter that is not needed.

305:    Level: intermediate

307: .seealso: NEPSetDimensions()
308: @*/
309: PetscErrorCode NEPGetDimensions(NEP nep,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
310: {
311:   PetscFunctionBegin;
313:   if (nev) *nev = nep->nev;
314:   if (ncv) *ncv = nep->ncv;
315:   if (mpd) *mpd = nep->mpd;
316:   PetscFunctionReturn(PETSC_SUCCESS);
317: }

319: /*@
320:    NEPSetDimensions - Sets the number of eigenvalues to compute
321:    and the dimension of the subspace.

323:    Logically Collective

325:    Input Parameters:
326: +  nep - the nonlinear eigensolver context
327: .  nev - number of eigenvalues to compute
328: .  ncv - the maximum dimension of the subspace to be used by the solver
329: -  mpd - the maximum dimension allowed for the projected problem

331:    Options Database Keys:
332: +  -nep_nev <nev> - Sets the number of eigenvalues
333: .  -nep_ncv <ncv> - Sets the dimension of the subspace
334: -  -nep_mpd <mpd> - Sets the maximum projected dimension

336:    Notes:
337:    Use PETSC_DEFAULT for ncv and mpd to assign a reasonably good value, which is
338:    dependent on the solution method.

340:    The parameters ncv and mpd are intimately related, so that the user is advised
341:    to set one of them at most. Normal usage is that
342:    (a) in cases where nev is small, the user sets ncv (a reasonable default is 2*nev); and
343:    (b) in cases where nev is large, the user sets mpd.

345:    The value of ncv should always be between nev and (nev+mpd), typically
346:    ncv=nev+mpd. If nev is not too large, mpd=nev is a reasonable choice, otherwise
347:    a smaller value should be used.

349:    Level: intermediate

351: .seealso: NEPGetDimensions()
352: @*/
353: PetscErrorCode NEPSetDimensions(NEP nep,PetscInt nev,PetscInt ncv,PetscInt mpd)
354: {
355:   PetscFunctionBegin;
360:   PetscCheck(nev>0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
361:   nep->nev = nev;
362:   if (ncv == PETSC_DECIDE || ncv == PETSC_DEFAULT) {
363:     nep->ncv = PETSC_DEFAULT;
364:   } else {
365:     PetscCheck(ncv>0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
366:     nep->ncv = ncv;
367:   }
368:   if (mpd == PETSC_DECIDE || mpd == PETSC_DEFAULT) {
369:     nep->mpd = PETSC_DEFAULT;
370:   } else {
371:     PetscCheck(mpd>0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
372:     nep->mpd = mpd;
373:   }
374:   nep->state = NEP_STATE_INITIAL;
375:   PetscFunctionReturn(PETSC_SUCCESS);
376: }

378: /*@
379:     NEPSetWhichEigenpairs - Specifies which portion of the spectrum is
380:     to be sought.

382:     Logically Collective

384:     Input Parameters:
385: +   nep   - eigensolver context obtained from NEPCreate()
386: -   which - the portion of the spectrum to be sought

388:     Options Database Keys:
389: +   -nep_largest_magnitude - Sets largest eigenvalues in magnitude
390: .   -nep_smallest_magnitude - Sets smallest eigenvalues in magnitude
391: .   -nep_largest_real - Sets largest real parts
392: .   -nep_smallest_real - Sets smallest real parts
393: .   -nep_largest_imaginary - Sets largest imaginary parts
394: .   -nep_smallest_imaginary - Sets smallest imaginary parts
395: .   -nep_target_magnitude - Sets eigenvalues closest to target
396: .   -nep_target_real - Sets real parts closest to target
397: .   -nep_target_imaginary - Sets imaginary parts closest to target
398: -   -nep_all - Sets all eigenvalues in a region

400:     Notes:
401:     The parameter 'which' can have one of these values

403: +     NEP_LARGEST_MAGNITUDE - largest eigenvalues in magnitude (default)
404: .     NEP_SMALLEST_MAGNITUDE - smallest eigenvalues in magnitude
405: .     NEP_LARGEST_REAL - largest real parts
406: .     NEP_SMALLEST_REAL - smallest real parts
407: .     NEP_LARGEST_IMAGINARY - largest imaginary parts
408: .     NEP_SMALLEST_IMAGINARY - smallest imaginary parts
409: .     NEP_TARGET_MAGNITUDE - eigenvalues closest to the target (in magnitude)
410: .     NEP_TARGET_REAL - eigenvalues with real part closest to target
411: .     NEP_TARGET_IMAGINARY - eigenvalues with imaginary part closest to target
412: .     NEP_ALL - all eigenvalues contained in a given region
413: -     NEP_WHICH_USER - user defined ordering set with NEPSetEigenvalueComparison()

415:     Not all eigensolvers implemented in NEP account for all the possible values
416:     stated above. If SLEPc is compiled for real numbers NEP_LARGEST_IMAGINARY
417:     and NEP_SMALLEST_IMAGINARY use the absolute value of the imaginary part
418:     for eigenvalue selection.

420:     The target is a scalar value provided with NEPSetTarget().

422:     NEP_ALL is intended for use in the context of the CISS solver for
423:     computing all eigenvalues in a region.

425:     Level: intermediate

427: .seealso: NEPGetWhichEigenpairs(), NEPSetTarget(), NEPSetEigenvalueComparison(), NEPWhich
428: @*/
429: PetscErrorCode NEPSetWhichEigenpairs(NEP nep,NEPWhich which)
430: {
431:   PetscFunctionBegin;
434:   switch (which) {
435:     case NEP_LARGEST_MAGNITUDE:
436:     case NEP_SMALLEST_MAGNITUDE:
437:     case NEP_LARGEST_REAL:
438:     case NEP_SMALLEST_REAL:
439:     case NEP_LARGEST_IMAGINARY:
440:     case NEP_SMALLEST_IMAGINARY:
441:     case NEP_TARGET_MAGNITUDE:
442:     case NEP_TARGET_REAL:
443: #if defined(PETSC_USE_COMPLEX)
444:     case NEP_TARGET_IMAGINARY:
445: #endif
446:     case NEP_ALL:
447:     case NEP_WHICH_USER:
448:       if (nep->which != which) {
449:         nep->state = NEP_STATE_INITIAL;
450:         nep->which = which;
451:       }
452:       break;
453: #if !defined(PETSC_USE_COMPLEX)
454:     case NEP_TARGET_IMAGINARY:
455:       SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_SUP,"NEP_TARGET_IMAGINARY can be used only with complex scalars");
456: #endif
457:     default:
458:       SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'which' value");
459:   }
460:   PetscFunctionReturn(PETSC_SUCCESS);
461: }

463: /*@
464:     NEPGetWhichEigenpairs - Returns which portion of the spectrum is to be
465:     sought.

467:     Not Collective

469:     Input Parameter:
470: .   nep - eigensolver context obtained from NEPCreate()

472:     Output Parameter:
473: .   which - the portion of the spectrum to be sought

475:     Notes:
476:     See NEPSetWhichEigenpairs() for possible values of 'which'.

478:     Level: intermediate

480: .seealso: NEPSetWhichEigenpairs(), NEPWhich
481: @*/
482: PetscErrorCode NEPGetWhichEigenpairs(NEP nep,NEPWhich *which)
483: {
484:   PetscFunctionBegin;
486:   PetscAssertPointer(which,2);
487:   *which = nep->which;
488:   PetscFunctionReturn(PETSC_SUCCESS);
489: }

491: /*@C
492:    NEPSetEigenvalueComparison - Specifies the eigenvalue comparison function
493:    when NEPSetWhichEigenpairs() is set to NEP_WHICH_USER.

495:    Logically Collective

497:    Input Parameters:
498: +  nep  - eigensolver context obtained from NEPCreate()
499: .  comp - a pointer to the comparison function
500: -  ctx  - a context pointer (the last parameter to the comparison function)

502:    Calling sequence of comp:
503: $  PetscErrorCode comp(PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *res,void *ctx)
504: +   ar     - real part of the 1st eigenvalue
505: .   ai     - imaginary part of the 1st eigenvalue
506: .   br     - real part of the 2nd eigenvalue
507: .   bi     - imaginary part of the 2nd eigenvalue
508: .   res    - result of comparison
509: -   ctx    - optional context, as set by NEPSetEigenvalueComparison()

511:    Note:
512:    The returning parameter 'res' can be
513: +  negative - if the 1st eigenvalue is preferred to the 2st one
514: .  zero     - if both eigenvalues are equally preferred
515: -  positive - if the 2st eigenvalue is preferred to the 1st one

517:    Level: advanced

519: .seealso: NEPSetWhichEigenpairs(), NEPWhich
520: @*/
521: PetscErrorCode NEPSetEigenvalueComparison(NEP nep,PetscErrorCode (*comp)(PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *res,void *ctx),void* ctx)
522: {
523:   PetscFunctionBegin;
525:   nep->sc->comparison    = comp;
526:   nep->sc->comparisonctx = ctx;
527:   nep->which             = NEP_WHICH_USER;
528:   PetscFunctionReturn(PETSC_SUCCESS);
529: }

531: /*@
532:    NEPSetProblemType - Specifies the type of the nonlinear eigenvalue problem.

534:    Logically Collective

536:    Input Parameters:
537: +  nep  - the nonlinear eigensolver context
538: -  type - a known type of nonlinear eigenvalue problem

540:    Options Database Keys:
541: +  -nep_general - general problem with no particular structure
542: -  -nep_rational - a rational eigenvalue problem defined in split form with all f_i rational

544:    Notes:
545:    Allowed values for the problem type are general (NEP_GENERAL), and rational
546:    (NEP_RATIONAL).

548:    This function is used to provide a hint to the NEP solver to exploit certain
549:    properties of the nonlinear eigenproblem. This hint may be used or not,
550:    depending on the solver. By default, no particular structure is assumed.

552:    Level: intermediate

554: .seealso: NEPSetType(), NEPGetProblemType(), NEPProblemType
555: @*/
556: PetscErrorCode NEPSetProblemType(NEP nep,NEPProblemType type)
557: {
558:   PetscFunctionBegin;
561:   PetscCheck(type==NEP_GENERAL || type==NEP_RATIONAL,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_WRONG,"Unknown eigenvalue problem type");
562:   if (type != nep->problem_type) {
563:     nep->problem_type = type;
564:     nep->state = NEP_STATE_INITIAL;
565:   }
566:   PetscFunctionReturn(PETSC_SUCCESS);
567: }

569: /*@
570:    NEPGetProblemType - Gets the problem type from the NEP object.

572:    Not Collective

574:    Input Parameter:
575: .  nep - the nonlinear eigensolver context

577:    Output Parameter:
578: .  type - the problem type

580:    Level: intermediate

582: .seealso: NEPSetProblemType(), NEPProblemType
583: @*/
584: PetscErrorCode NEPGetProblemType(NEP nep,NEPProblemType *type)
585: {
586:   PetscFunctionBegin;
588:   PetscAssertPointer(type,2);
589:   *type = nep->problem_type;
590:   PetscFunctionReturn(PETSC_SUCCESS);
591: }

593: /*@
594:    NEPSetTwoSided - Sets the solver to use a two-sided variant so that left
595:    eigenvectors are also computed.

597:    Logically Collective

599:    Input Parameters:
600: +  nep      - the eigensolver context
601: -  twosided - whether the two-sided variant is to be used or not

603:    Options Database Keys:
604: .  -nep_two_sided <boolean> - Sets/resets the twosided flag

606:    Notes:
607:    If the user sets twosided=PETSC_TRUE then the solver uses a variant of
608:    the algorithm that computes both right and left eigenvectors. This is
609:    usually much more costly. This option is not available in all solvers.

611:    When using two-sided solvers, the problem matrices must have both the
612:    MatMult and MatMultTranspose operations defined.

614:    Level: advanced

616: .seealso: NEPGetTwoSided(), NEPGetLeftEigenvector()
617: @*/
618: PetscErrorCode NEPSetTwoSided(NEP nep,PetscBool twosided)
619: {
620:   PetscFunctionBegin;
623:   if (twosided!=nep->twosided) {
624:     nep->twosided = twosided;
625:     nep->state    = NEP_STATE_INITIAL;
626:   }
627:   PetscFunctionReturn(PETSC_SUCCESS);
628: }

630: /*@
631:    NEPGetTwoSided - Returns the flag indicating whether a two-sided variant
632:    of the algorithm is being used or not.

634:    Not Collective

636:    Input Parameter:
637: .  nep - the eigensolver context

639:    Output Parameter:
640: .  twosided - the returned flag

642:    Level: advanced

644: .seealso: NEPSetTwoSided()
645: @*/
646: PetscErrorCode NEPGetTwoSided(NEP nep,PetscBool *twosided)
647: {
648:   PetscFunctionBegin;
650:   PetscAssertPointer(twosided,2);
651:   *twosided = nep->twosided;
652:   PetscFunctionReturn(PETSC_SUCCESS);
653: }

655: /*@C
656:    NEPSetConvergenceTestFunction - Sets a function to compute the error estimate
657:    used in the convergence test.

659:    Logically Collective

661:    Input Parameters:
662: +  nep     - nonlinear eigensolver context obtained from NEPCreate()
663: .  conv    - a pointer to the convergence test function
664: .  ctx     - context for private data for the convergence routine (may be null)
665: -  destroy - a routine for destroying the context (may be null)

667:    Calling sequence of conv:
668: $  PetscErrorCode conv(NEP nep,PetscScalar eigr,PetscScalar eigi,PetscReal res,PetscReal *errest,void *ctx)
669: +   nep    - nonlinear eigensolver context obtained from NEPCreate()
670: .   eigr   - real part of the eigenvalue
671: .   eigi   - imaginary part of the eigenvalue
672: .   res    - residual norm associated to the eigenpair
673: .   errest - (output) computed error estimate
674: -   ctx    - optional context, as set by NEPSetConvergenceTestFunction()

676:    Note:
677:    If the error estimate returned by the convergence test function is less than
678:    the tolerance, then the eigenvalue is accepted as converged.

680:    Level: advanced

682: .seealso: NEPSetConvergenceTest(), NEPSetTolerances()
683: @*/
684: PetscErrorCode NEPSetConvergenceTestFunction(NEP nep,PetscErrorCode (*conv)(NEP nep,PetscScalar eigr,PetscScalar eigi,PetscReal res,PetscReal *errest,void *ctx),void* ctx,PetscErrorCode (*destroy)(void*))
685: {
686:   PetscFunctionBegin;
688:   if (nep->convergeddestroy) PetscCall((*nep->convergeddestroy)(nep->convergedctx));
689:   nep->convergeduser    = conv;
690:   nep->convergeddestroy = destroy;
691:   nep->convergedctx     = ctx;
692:   if (conv == NEPConvergedRelative) nep->conv = NEP_CONV_REL;
693:   else if (conv == NEPConvergedNorm) nep->conv = NEP_CONV_NORM;
694:   else if (conv == NEPConvergedAbsolute) nep->conv = NEP_CONV_ABS;
695:   else {
696:     nep->conv      = NEP_CONV_USER;
697:     nep->converged = nep->convergeduser;
698:   }
699:   PetscFunctionReturn(PETSC_SUCCESS);
700: }

702: /*@
703:    NEPSetConvergenceTest - Specifies how to compute the error estimate
704:    used in the convergence test.

706:    Logically Collective

708:    Input Parameters:
709: +  nep  - nonlinear eigensolver context obtained from NEPCreate()
710: -  conv - the type of convergence test

712:    Options Database Keys:
713: +  -nep_conv_abs  - Sets the absolute convergence test
714: .  -nep_conv_rel  - Sets the convergence test relative to the eigenvalue
715: -  -nep_conv_user - Selects the user-defined convergence test

717:    Note:
718:    The parameter 'conv' can have one of these values
719: +     NEP_CONV_ABS  - absolute error ||r||
720: .     NEP_CONV_REL  - error relative to the eigenvalue l, ||r||/|l|
721: .     NEP_CONV_NORM - error relative matrix norms, ||r||/sum_i(|f_i(l)|*||A_i||)
722: -     NEP_CONV_USER - function set by NEPSetConvergenceTestFunction()

724:    Level: intermediate

726: .seealso: NEPGetConvergenceTest(), NEPSetConvergenceTestFunction(), NEPSetStoppingTest(), NEPConv
727: @*/
728: PetscErrorCode NEPSetConvergenceTest(NEP nep,NEPConv conv)
729: {
730:   PetscFunctionBegin;
733:   switch (conv) {
734:     case NEP_CONV_ABS:  nep->converged = NEPConvergedAbsolute; break;
735:     case NEP_CONV_REL:  nep->converged = NEPConvergedRelative; break;
736:     case NEP_CONV_NORM: nep->converged = NEPConvergedNorm; break;
737:     case NEP_CONV_USER:
738:       PetscCheck(nep->convergeduser,PetscObjectComm((PetscObject)nep),PETSC_ERR_ORDER,"Must call NEPSetConvergenceTestFunction() first");
739:       nep->converged = nep->convergeduser;
740:       break;
741:     default:
742:       SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'conv' value");
743:   }
744:   nep->conv = conv;
745:   PetscFunctionReturn(PETSC_SUCCESS);
746: }

748: /*@
749:    NEPGetConvergenceTest - Gets the method used to compute the error estimate
750:    used in the convergence test.

752:    Not Collective

754:    Input Parameters:
755: .  nep   - nonlinear eigensolver context obtained from NEPCreate()

757:    Output Parameters:
758: .  conv  - the type of convergence test

760:    Level: intermediate

762: .seealso: NEPSetConvergenceTest(), NEPConv
763: @*/
764: PetscErrorCode NEPGetConvergenceTest(NEP nep,NEPConv *conv)
765: {
766:   PetscFunctionBegin;
768:   PetscAssertPointer(conv,2);
769:   *conv = nep->conv;
770:   PetscFunctionReturn(PETSC_SUCCESS);
771: }

773: /*@C
774:    NEPSetStoppingTestFunction - Sets a function to decide when to stop the outer
775:    iteration of the eigensolver.

777:    Logically Collective

779:    Input Parameters:
780: +  nep     - nonlinear eigensolver context obtained from NEPCreate()
781: .  stop    - pointer to the stopping test function
782: .  ctx     - context for private data for the stopping routine (may be null)
783: -  destroy - a routine for destroying the context (may be null)

785:    Calling sequence of stop:
786: $  PetscErrorCode stop(NEP nep,PetscInt its,PetscInt max_its,PetscInt nconv,PetscInt nev,NEPConvergedReason *reason,void *ctx)
787: +   nep    - nonlinear eigensolver context obtained from NEPCreate()
788: .   its    - current number of iterations
789: .   max_its - maximum number of iterations
790: .   nconv  - number of currently converged eigenpairs
791: .   nev    - number of requested eigenpairs
792: .   reason - (output) result of the stopping test
793: -   ctx    - optional context, as set by NEPSetStoppingTestFunction()

795:    Note:
796:    Normal usage is to first call the default routine NEPStoppingBasic() and then
797:    set reason to NEP_CONVERGED_USER if some user-defined conditions have been
798:    met. To let the eigensolver continue iterating, the result must be left as
799:    NEP_CONVERGED_ITERATING.

801:    Level: advanced

803: .seealso: NEPSetStoppingTest(), NEPStoppingBasic()
804: @*/
805: PetscErrorCode NEPSetStoppingTestFunction(NEP nep,PetscErrorCode (*stop)(NEP nep,PetscInt its,PetscInt max_its,PetscInt nconv,PetscInt nev,NEPConvergedReason *reason,void *ctx),void* ctx,PetscErrorCode (*destroy)(void*))
806: {
807:   PetscFunctionBegin;
809:   if (nep->stoppingdestroy) PetscCall((*nep->stoppingdestroy)(nep->stoppingctx));
810:   nep->stoppinguser    = stop;
811:   nep->stoppingdestroy = destroy;
812:   nep->stoppingctx     = ctx;
813:   if (stop == NEPStoppingBasic) nep->stop = NEP_STOP_BASIC;
814:   else {
815:     nep->stop     = NEP_STOP_USER;
816:     nep->stopping = nep->stoppinguser;
817:   }
818:   PetscFunctionReturn(PETSC_SUCCESS);
819: }

821: /*@
822:    NEPSetStoppingTest - Specifies how to decide the termination of the outer
823:    loop of the eigensolver.

825:    Logically Collective

827:    Input Parameters:
828: +  nep  - nonlinear eigensolver context obtained from NEPCreate()
829: -  stop - the type of stopping test

831:    Options Database Keys:
832: +  -nep_stop_basic - Sets the default stopping test
833: -  -nep_stop_user  - Selects the user-defined stopping test

835:    Note:
836:    The parameter 'stop' can have one of these values
837: +     NEP_STOP_BASIC - default stopping test
838: -     NEP_STOP_USER  - function set by NEPSetStoppingTestFunction()

840:    Level: advanced

842: .seealso: NEPGetStoppingTest(), NEPSetStoppingTestFunction(), NEPSetConvergenceTest(), NEPStop
843: @*/
844: PetscErrorCode NEPSetStoppingTest(NEP nep,NEPStop stop)
845: {
846:   PetscFunctionBegin;
849:   switch (stop) {
850:     case NEP_STOP_BASIC: nep->stopping = NEPStoppingBasic; break;
851:     case NEP_STOP_USER:
852:       PetscCheck(nep->stoppinguser,PetscObjectComm((PetscObject)nep),PETSC_ERR_ORDER,"Must call NEPSetStoppingTestFunction() first");
853:       nep->stopping = nep->stoppinguser;
854:       break;
855:     default:
856:       SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'stop' value");
857:   }
858:   nep->stop = stop;
859:   PetscFunctionReturn(PETSC_SUCCESS);
860: }

862: /*@
863:    NEPGetStoppingTest - Gets the method used to decide the termination of the outer
864:    loop of the eigensolver.

866:    Not Collective

868:    Input Parameters:
869: .  nep   - nonlinear eigensolver context obtained from NEPCreate()

871:    Output Parameters:
872: .  stop  - the type of stopping test

874:    Level: advanced

876: .seealso: NEPSetStoppingTest(), NEPStop
877: @*/
878: PetscErrorCode NEPGetStoppingTest(NEP nep,NEPStop *stop)
879: {
880:   PetscFunctionBegin;
882:   PetscAssertPointer(stop,2);
883:   *stop = nep->stop;
884:   PetscFunctionReturn(PETSC_SUCCESS);
885: }

887: /*@
888:    NEPSetTrackAll - Specifies if the solver must compute the residual of all
889:    approximate eigenpairs or not.

891:    Logically Collective

893:    Input Parameters:
894: +  nep      - the eigensolver context
895: -  trackall - whether compute all residuals or not

897:    Notes:
898:    If the user sets trackall=PETSC_TRUE then the solver explicitly computes
899:    the residual for each eigenpair approximation. Computing the residual is
900:    usually an expensive operation and solvers commonly compute the associated
901:    residual to the first unconverged eigenpair.

903:    The option '-nep_monitor_all' automatically activates this option.

905:    Level: developer

907: .seealso: NEPGetTrackAll()
908: @*/
909: PetscErrorCode NEPSetTrackAll(NEP nep,PetscBool trackall)
910: {
911:   PetscFunctionBegin;
914:   nep->trackall = trackall;
915:   PetscFunctionReturn(PETSC_SUCCESS);
916: }

918: /*@
919:    NEPGetTrackAll - Returns the flag indicating whether all residual norms must
920:    be computed or not.

922:    Not Collective

924:    Input Parameter:
925: .  nep - the eigensolver context

927:    Output Parameter:
928: .  trackall - the returned flag

930:    Level: developer

932: .seealso: NEPSetTrackAll()
933: @*/
934: PetscErrorCode NEPGetTrackAll(NEP nep,PetscBool *trackall)
935: {
936:   PetscFunctionBegin;
938:   PetscAssertPointer(trackall,2);
939:   *trackall = nep->trackall;
940:   PetscFunctionReturn(PETSC_SUCCESS);
941: }

943: /*@
944:    NEPSetRefine - Specifies the refinement type (and options) to be used
945:    after the solve.

947:    Logically Collective

949:    Input Parameters:
950: +  nep    - the nonlinear eigensolver context
951: .  refine - refinement type
952: .  npart  - number of partitions of the communicator
953: .  tol    - the convergence tolerance
954: .  its    - maximum number of refinement iterations
955: -  scheme - which scheme to be used for solving the involved linear systems

957:    Options Database Keys:
958: +  -nep_refine <type> - refinement type, one of <none,simple,multiple>
959: .  -nep_refine_partitions <n> - the number of partitions
960: .  -nep_refine_tol <tol> - the tolerance
961: .  -nep_refine_its <its> - number of iterations
962: -  -nep_refine_scheme - to set the scheme for the linear solves

964:    Notes:
965:    By default, iterative refinement is disabled, since it may be very
966:    costly. There are two possible refinement strategies, simple and multiple.
967:    The simple approach performs iterative refinement on each of the
968:    converged eigenpairs individually, whereas the multiple strategy works
969:    with the invariant pair as a whole, refining all eigenpairs simultaneously.
970:    The latter may be required for the case of multiple eigenvalues.

972:    In some cases, especially when using direct solvers within the
973:    iterative refinement method, it may be helpful for improved scalability
974:    to split the communicator in several partitions. The npart parameter
975:    indicates how many partitions to use (defaults to 1).

977:    The tol and its parameters specify the stopping criterion. In the simple
978:    method, refinement continues until the residual of each eigenpair is
979:    below the tolerance (tol defaults to the NEP tol, but may be set to a
980:    different value). In contrast, the multiple method simply performs its
981:    refinement iterations (just one by default).

983:    The scheme argument is used to change the way in which linear systems are
984:    solved. Possible choices are explicit, mixed block elimination (MBE),
985:    and Schur complement.

987:    Level: intermediate

989: .seealso: NEPGetRefine()
990: @*/
991: PetscErrorCode NEPSetRefine(NEP nep,NEPRefine refine,PetscInt npart,PetscReal tol,PetscInt its,NEPRefineScheme scheme)
992: {
993:   PetscMPIInt    size;

995:   PetscFunctionBegin;
1002:   nep->refine = refine;
1003:   if (refine) {  /* process parameters only if not REFINE_NONE */
1004:     if (npart!=nep->npart) {
1005:       PetscCall(PetscSubcommDestroy(&nep->refinesubc));
1006:       PetscCall(KSPDestroy(&nep->refineksp));
1007:     }
1008:     if (npart == PETSC_DEFAULT || npart == PETSC_DECIDE) {
1009:       nep->npart = 1;
1010:     } else {
1011:       PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)nep),&size));
1012:       PetscCheck(npart>0 && npart<=size,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of npart");
1013:       nep->npart = npart;
1014:     }
1015:     if (tol == (PetscReal)PETSC_DEFAULT || tol == (PetscReal)PETSC_DECIDE) {
1016:       nep->rtol = PETSC_DEFAULT;
1017:     } else {
1018:       PetscCheck(tol>0.0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
1019:       nep->rtol = tol;
1020:     }
1021:     if (its==PETSC_DECIDE || its==PETSC_DEFAULT) {
1022:       nep->rits = PETSC_DEFAULT;
1023:     } else {
1024:       PetscCheck(its>=0,PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be >= 0");
1025:       nep->rits = its;
1026:     }
1027:     nep->scheme = scheme;
1028:   }
1029:   nep->state = NEP_STATE_INITIAL;
1030:   PetscFunctionReturn(PETSC_SUCCESS);
1031: }

1033: /*@C
1034:    NEPGetRefine - Gets the refinement strategy used by the NEP object, and the
1035:    associated parameters.

1037:    Not Collective

1039:    Input Parameter:
1040: .  nep - the nonlinear eigensolver context

1042:    Output Parameters:
1043: +  refine - refinement type
1044: .  npart  - number of partitions of the communicator
1045: .  tol    - the convergence tolerance
1046: .  its    - maximum number of refinement iterations
1047: -  scheme - the scheme used for solving linear systems

1049:    Level: intermediate

1051:    Note:
1052:    The user can specify NULL for any parameter that is not needed.

1054: .seealso: NEPSetRefine()
1055: @*/
1056: PetscErrorCode NEPGetRefine(NEP nep,NEPRefine *refine,PetscInt *npart,PetscReal *tol,PetscInt *its,NEPRefineScheme *scheme)
1057: {
1058:   PetscFunctionBegin;
1060:   if (refine) *refine = nep->refine;
1061:   if (npart)  *npart  = nep->npart;
1062:   if (tol)    *tol    = nep->rtol;
1063:   if (its)    *its    = nep->rits;
1064:   if (scheme) *scheme = nep->scheme;
1065:   PetscFunctionReturn(PETSC_SUCCESS);
1066: }

1068: /*@C
1069:    NEPSetOptionsPrefix - Sets the prefix used for searching for all
1070:    NEP options in the database.

1072:    Logically Collective

1074:    Input Parameters:
1075: +  nep - the nonlinear eigensolver context
1076: -  prefix - the prefix string to prepend to all NEP option requests

1078:    Notes:
1079:    A hyphen (-) must NOT be given at the beginning of the prefix name.
1080:    The first character of all runtime options is AUTOMATICALLY the
1081:    hyphen.

1083:    For example, to distinguish between the runtime options for two
1084:    different NEP contexts, one could call
1085: .vb
1086:       NEPSetOptionsPrefix(nep1,"neig1_")
1087:       NEPSetOptionsPrefix(nep2,"neig2_")
1088: .ve

1090:    Level: advanced

1092: .seealso: NEPAppendOptionsPrefix(), NEPGetOptionsPrefix()
1093: @*/
1094: PetscErrorCode NEPSetOptionsPrefix(NEP nep,const char *prefix)
1095: {
1096:   PetscFunctionBegin;
1098:   if (!nep->V) PetscCall(NEPGetBV(nep,&nep->V));
1099:   PetscCall(BVSetOptionsPrefix(nep->V,prefix));
1100:   if (!nep->ds) PetscCall(NEPGetDS(nep,&nep->ds));
1101:   PetscCall(DSSetOptionsPrefix(nep->ds,prefix));
1102:   if (!nep->rg) PetscCall(NEPGetRG(nep,&nep->rg));
1103:   PetscCall(RGSetOptionsPrefix(nep->rg,prefix));
1104:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)nep,prefix));
1105:   PetscFunctionReturn(PETSC_SUCCESS);
1106: }

1108: /*@C
1109:    NEPAppendOptionsPrefix - Appends to the prefix used for searching for all
1110:    NEP options in the database.

1112:    Logically Collective

1114:    Input Parameters:
1115: +  nep - the nonlinear eigensolver context
1116: -  prefix - the prefix string to prepend to all NEP option requests

1118:    Notes:
1119:    A hyphen (-) must NOT be given at the beginning of the prefix name.
1120:    The first character of all runtime options is AUTOMATICALLY the hyphen.

1122:    Level: advanced

1124: .seealso: NEPSetOptionsPrefix(), NEPGetOptionsPrefix()
1125: @*/
1126: PetscErrorCode NEPAppendOptionsPrefix(NEP nep,const char *prefix)
1127: {
1128:   PetscFunctionBegin;
1130:   if (!nep->V) PetscCall(NEPGetBV(nep,&nep->V));
1131:   PetscCall(BVAppendOptionsPrefix(nep->V,prefix));
1132:   if (!nep->ds) PetscCall(NEPGetDS(nep,&nep->ds));
1133:   PetscCall(DSAppendOptionsPrefix(nep->ds,prefix));
1134:   if (!nep->rg) PetscCall(NEPGetRG(nep,&nep->rg));
1135:   PetscCall(RGAppendOptionsPrefix(nep->rg,prefix));
1136:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)nep,prefix));
1137:   PetscFunctionReturn(PETSC_SUCCESS);
1138: }

1140: /*@C
1141:    NEPGetOptionsPrefix - Gets the prefix used for searching for all
1142:    NEP options in the database.

1144:    Not Collective

1146:    Input Parameters:
1147: .  nep - the nonlinear eigensolver context

1149:    Output Parameters:
1150: .  prefix - pointer to the prefix string used is returned

1152:    Note:
1153:    On the Fortran side, the user should pass in a string 'prefix' of
1154:    sufficient length to hold the prefix.

1156:    Level: advanced

1158: .seealso: NEPSetOptionsPrefix(), NEPAppendOptionsPrefix()
1159: @*/
1160: PetscErrorCode NEPGetOptionsPrefix(NEP nep,const char *prefix[])
1161: {
1162:   PetscFunctionBegin;
1164:   PetscAssertPointer(prefix,2);
1165:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)nep,prefix));
1166:   PetscFunctionReturn(PETSC_SUCCESS);
1167: }