Actual source code: epsopts.c

slepc-3.14.2 2021-02-01
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2020, 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:    EPS routines related to options that can be set via the command-line
 12:    or procedurally.
 13: */

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

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

 22:    Collective on eps

 24:    Input Parameters:
 25: +  eps      - the eigensolver context
 26: .  name     - the monitor option name
 27: .  help     - message indicating what monitoring is done
 28: .  manual   - manual page for the monitor
 29: .  monitor  - the monitor function, whose context is a PetscViewerAndFormat
 30: -  trackall - whether this monitor tracks all eigenvalues or not

 32:    Level: developer

 34: .seealso: EPSMonitorSet(), EPSSetTrackAll(), EPSConvMonitorSetFromOptions()
 35: @*/
 36: PetscErrorCode EPSMonitorSetFromOptions(EPS eps,const char name[],const char help[],const char manual[],PetscErrorCode (*monitor)(EPS,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,PetscViewerAndFormat*),PetscBool trackall)
 37: {
 38:   PetscErrorCode       ierr;
 39:   PetscBool            flg;
 40:   PetscViewer          viewer;
 41:   PetscViewerFormat    format;
 42:   PetscViewerAndFormat *vf;

 45:   PetscOptionsGetViewer(PetscObjectComm((PetscObject)eps),((PetscObject)eps)->options,((PetscObject)eps)->prefix,name,&viewer,&format,&flg);
 46:   if (flg) {
 47:     PetscViewerAndFormatCreate(viewer,format,&vf);
 48:     PetscObjectDereference((PetscObject)viewer);
 49:     EPSMonitorSet(eps,(PetscErrorCode (*)(EPS,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,void*))monitor,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
 50:     if (trackall) {
 51:       EPSSetTrackAll(eps,PETSC_TRUE);
 52:     }
 53:   }
 54:   return(0);
 55: }

 57: /*@C
 58:    EPSConvMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type
 59:    indicated by the user (for monitors that only show iteration numbers of convergence).

 61:    Collective on eps

 63:    Input Parameters:
 64: +  eps      - the eigensolver context
 65: .  name     - the monitor option name
 66: .  help     - message indicating what monitoring is done
 67: .  manual   - manual page for the monitor
 68: -  monitor  - the monitor function, whose context is a SlepcConvMonitor

 70:    Level: developer

 72: .seealso: EPSMonitorSet(), EPSMonitorSetFromOptions()
 73: @*/
 74: PetscErrorCode EPSConvMonitorSetFromOptions(EPS eps,const char name[],const char help[],const char manual[],PetscErrorCode (*monitor)(EPS,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,SlepcConvMonitor))
 75: {
 76:   PetscErrorCode    ierr;
 77:   PetscBool         flg;
 78:   PetscViewer       viewer;
 79:   PetscViewerFormat format;
 80:   SlepcConvMonitor  ctx;

 83:   PetscOptionsGetViewer(PetscObjectComm((PetscObject)eps),((PetscObject)eps)->options,((PetscObject)eps)->prefix,name,&viewer,&format,&flg);
 84:   if (flg) {
 85:     SlepcConvMonitorCreate(viewer,format,&ctx);
 86:     PetscObjectDereference((PetscObject)viewer);
 87:     EPSMonitorSet(eps,(PetscErrorCode (*)(EPS,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,void*))monitor,ctx,(PetscErrorCode (*)(void**))SlepcConvMonitorDestroy);
 88:   }
 89:   return(0);
 90: }

 92: /*@
 93:    EPSSetFromOptions - Sets EPS options from the options database.
 94:    This routine must be called before EPSSetUp() if the user is to be
 95:    allowed to set the solver type.

 97:    Collective on eps

 99:    Input Parameters:
100: .  eps - the eigensolver context

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

105:    Level: beginner
106: @*/
107: PetscErrorCode EPSSetFromOptions(EPS eps)
108: {
110:   char           type[256];
111:   PetscBool      set,flg,flg1,flg2,flg3,bval;
112:   PetscReal      r,array[2]={0,0};
113:   PetscScalar    s;
114:   PetscInt       i,j,k;
115:   PetscDrawLG    lg;
116:   EPSBalance     bal;

120:   EPSRegisterAll();
121:   PetscObjectOptionsBegin((PetscObject)eps);
122:     PetscOptionsFList("-eps_type","Eigensolver method","EPSSetType",EPSList,(char*)(((PetscObject)eps)->type_name?((PetscObject)eps)->type_name:EPSKRYLOVSCHUR),type,sizeof(type),&flg);
123:     if (flg) {
124:       EPSSetType(eps,type);
125:     } else if (!((PetscObject)eps)->type_name) {
126:       EPSSetType(eps,EPSKRYLOVSCHUR);
127:     }

129:     PetscOptionsBoolGroupBegin("-eps_hermitian","Hermitian eigenvalue problem","EPSSetProblemType",&flg);
130:     if (flg) { EPSSetProblemType(eps,EPS_HEP); }
131:     PetscOptionsBoolGroup("-eps_gen_hermitian","Generalized Hermitian eigenvalue problem","EPSSetProblemType",&flg);
132:     if (flg) { EPSSetProblemType(eps,EPS_GHEP); }
133:     PetscOptionsBoolGroup("-eps_non_hermitian","Non-Hermitian eigenvalue problem","EPSSetProblemType",&flg);
134:     if (flg) { EPSSetProblemType(eps,EPS_NHEP); }
135:     PetscOptionsBoolGroup("-eps_gen_non_hermitian","Generalized non-Hermitian eigenvalue problem","EPSSetProblemType",&flg);
136:     if (flg) { EPSSetProblemType(eps,EPS_GNHEP); }
137:     PetscOptionsBoolGroup("-eps_pos_gen_non_hermitian","Generalized non-Hermitian eigenvalue problem with positive semi-definite B","EPSSetProblemType",&flg);
138:     if (flg) { EPSSetProblemType(eps,EPS_PGNHEP); }
139:     PetscOptionsBoolGroupEnd("-eps_gen_indefinite","Generalized Hermitian-indefinite eigenvalue problem","EPSSetProblemType",&flg);
140:     if (flg) { EPSSetProblemType(eps,EPS_GHIEP); }

142:     PetscOptionsBoolGroupBegin("-eps_ritz","Rayleigh-Ritz extraction","EPSSetExtraction",&flg);
143:     if (flg) { EPSSetExtraction(eps,EPS_RITZ); }
144:     PetscOptionsBoolGroup("-eps_harmonic","Harmonic Ritz extraction","EPSSetExtraction",&flg);
145:     if (flg) { EPSSetExtraction(eps,EPS_HARMONIC); }
146:     PetscOptionsBoolGroup("-eps_harmonic_relative","Relative harmonic Ritz extraction","EPSSetExtraction",&flg);
147:     if (flg) { EPSSetExtraction(eps,EPS_HARMONIC_RELATIVE); }
148:     PetscOptionsBoolGroup("-eps_harmonic_right","Right harmonic Ritz extraction","EPSSetExtraction",&flg);
149:     if (flg) { EPSSetExtraction(eps,EPS_HARMONIC_RIGHT); }
150:     PetscOptionsBoolGroup("-eps_harmonic_largest","Largest harmonic Ritz extraction","EPSSetExtraction",&flg);
151:     if (flg) { EPSSetExtraction(eps,EPS_HARMONIC_LARGEST); }
152:     PetscOptionsBoolGroup("-eps_refined","Refined Ritz extraction","EPSSetExtraction",&flg);
153:     if (flg) { EPSSetExtraction(eps,EPS_REFINED); }
154:     PetscOptionsBoolGroupEnd("-eps_refined_harmonic","Refined harmonic Ritz extraction","EPSSetExtraction",&flg);
155:     if (flg) { EPSSetExtraction(eps,EPS_REFINED_HARMONIC); }

157:     bal = eps->balance;
158:     PetscOptionsEnum("-eps_balance","Balancing method","EPSSetBalance",EPSBalanceTypes,(PetscEnum)bal,(PetscEnum*)&bal,&flg1);
159:     j = eps->balance_its;
160:     PetscOptionsInt("-eps_balance_its","Number of iterations in balancing","EPSSetBalance",eps->balance_its,&j,&flg2);
161:     r = eps->balance_cutoff;
162:     PetscOptionsReal("-eps_balance_cutoff","Cutoff value in balancing","EPSSetBalance",eps->balance_cutoff,&r,&flg3);
163:     if (flg1 || flg2 || flg3) { EPSSetBalance(eps,bal,j,r); }

165:     i = eps->max_it;
166:     PetscOptionsInt("-eps_max_it","Maximum number of iterations","EPSSetTolerances",eps->max_it,&i,&flg1);
167:     r = eps->tol;
168:     PetscOptionsReal("-eps_tol","Tolerance","EPSSetTolerances",eps->tol==PETSC_DEFAULT?SLEPC_DEFAULT_TOL:eps->tol,&r,&flg2);
169:     if (flg1 || flg2) { EPSSetTolerances(eps,r,i); }

171:     PetscOptionsBoolGroupBegin("-eps_conv_rel","Relative error convergence test","EPSSetConvergenceTest",&flg);
172:     if (flg) { EPSSetConvergenceTest(eps,EPS_CONV_REL); }
173:     PetscOptionsBoolGroup("-eps_conv_norm","Convergence test relative to the eigenvalue and the matrix norms","EPSSetConvergenceTest",&flg);
174:     if (flg) { EPSSetConvergenceTest(eps,EPS_CONV_NORM); }
175:     PetscOptionsBoolGroup("-eps_conv_abs","Absolute error convergence test","EPSSetConvergenceTest",&flg);
176:     if (flg) { EPSSetConvergenceTest(eps,EPS_CONV_ABS); }
177:     PetscOptionsBoolGroupEnd("-eps_conv_user","User-defined convergence test","EPSSetConvergenceTest",&flg);
178:     if (flg) { EPSSetConvergenceTest(eps,EPS_CONV_USER); }

180:     PetscOptionsBoolGroupBegin("-eps_stop_basic","Stop iteration if all eigenvalues converged or max_it reached","EPSSetStoppingTest",&flg);
181:     if (flg) { EPSSetStoppingTest(eps,EPS_STOP_BASIC); }
182:     PetscOptionsBoolGroupEnd("-eps_stop_user","User-defined stopping test","EPSSetStoppingTest",&flg);
183:     if (flg) { EPSSetStoppingTest(eps,EPS_STOP_USER); }

185:     i = eps->nev;
186:     PetscOptionsInt("-eps_nev","Number of eigenvalues to compute","EPSSetDimensions",eps->nev,&i,&flg1);
187:     j = eps->ncv;
188:     PetscOptionsInt("-eps_ncv","Number of basis vectors","EPSSetDimensions",eps->ncv,&j,&flg2);
189:     k = eps->mpd;
190:     PetscOptionsInt("-eps_mpd","Maximum dimension of projected problem","EPSSetDimensions",eps->mpd,&k,&flg3);
191:     if (flg1 || flg2 || flg3) { EPSSetDimensions(eps,i,j,k); }

193:     PetscOptionsBoolGroupBegin("-eps_largest_magnitude","Compute largest eigenvalues in magnitude","EPSSetWhichEigenpairs",&flg);
194:     if (flg) { EPSSetWhichEigenpairs(eps,EPS_LARGEST_MAGNITUDE); }
195:     PetscOptionsBoolGroup("-eps_smallest_magnitude","Compute smallest eigenvalues in magnitude","EPSSetWhichEigenpairs",&flg);
196:     if (flg) { EPSSetWhichEigenpairs(eps,EPS_SMALLEST_MAGNITUDE); }
197:     PetscOptionsBoolGroup("-eps_largest_real","Compute eigenvalues with largest real parts","EPSSetWhichEigenpairs",&flg);
198:     if (flg) { EPSSetWhichEigenpairs(eps,EPS_LARGEST_REAL); }
199:     PetscOptionsBoolGroup("-eps_smallest_real","Compute eigenvalues with smallest real parts","EPSSetWhichEigenpairs",&flg);
200:     if (flg) { EPSSetWhichEigenpairs(eps,EPS_SMALLEST_REAL); }
201:     PetscOptionsBoolGroup("-eps_largest_imaginary","Compute eigenvalues with largest imaginary parts","EPSSetWhichEigenpairs",&flg);
202:     if (flg) { EPSSetWhichEigenpairs(eps,EPS_LARGEST_IMAGINARY); }
203:     PetscOptionsBoolGroup("-eps_smallest_imaginary","Compute eigenvalues with smallest imaginary parts","EPSSetWhichEigenpairs",&flg);
204:     if (flg) { EPSSetWhichEigenpairs(eps,EPS_SMALLEST_IMAGINARY); }
205:     PetscOptionsBoolGroup("-eps_target_magnitude","Compute eigenvalues closest to target","EPSSetWhichEigenpairs",&flg);
206:     if (flg) { EPSSetWhichEigenpairs(eps,EPS_TARGET_MAGNITUDE); }
207:     PetscOptionsBoolGroup("-eps_target_real","Compute eigenvalues with real parts closest to target","EPSSetWhichEigenpairs",&flg);
208:     if (flg) { EPSSetWhichEigenpairs(eps,EPS_TARGET_REAL); }
209:     PetscOptionsBoolGroup("-eps_target_imaginary","Compute eigenvalues with imaginary parts closest to target","EPSSetWhichEigenpairs",&flg);
210:     if (flg) { EPSSetWhichEigenpairs(eps,EPS_TARGET_IMAGINARY); }
211:     PetscOptionsBoolGroupEnd("-eps_all","Compute all eigenvalues in an interval or a region","EPSSetWhichEigenpairs",&flg);
212:     if (flg) { EPSSetWhichEigenpairs(eps,EPS_ALL); }

214:     PetscOptionsScalar("-eps_target","Value of the target","EPSSetTarget",eps->target,&s,&flg);
215:     if (flg) {
216:       if (eps->which!=EPS_TARGET_REAL && eps->which!=EPS_TARGET_IMAGINARY) {
217:         EPSSetWhichEigenpairs(eps,EPS_TARGET_MAGNITUDE);
218:       }
219:       EPSSetTarget(eps,s);
220:     }

222:     k = 2;
223:     PetscOptionsRealArray("-eps_interval","Computational interval (two real values separated with a comma without spaces)","EPSSetInterval",array,&k,&flg);
224:     if (flg) {
225:       if (k<2) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_SIZ,"Must pass two values in -eps_interval (comma-separated without spaces)");
226:       EPSSetWhichEigenpairs(eps,EPS_ALL);
227:       EPSSetInterval(eps,array[0],array[1]);
228:     }

230:     PetscOptionsBool("-eps_true_residual","Compute true residuals explicitly","EPSSetTrueResidual",eps->trueres,&eps->trueres,NULL);
231:     PetscOptionsBool("-eps_purify","Postprocess eigenvectors for purification","EPSSetPurify",eps->purify,&bval,&flg);
232:     if (flg) { EPSSetPurify(eps,bval); }
233:     PetscOptionsBool("-eps_two_sided","Use two-sided variant (to compute left eigenvectors)","EPSSetTwoSided",eps->twosided,&bval,&flg);
234:     if (flg) { EPSSetTwoSided(eps,bval); }

236:     /* -----------------------------------------------------------------------*/
237:     /*
238:       Cancels all monitors hardwired into code before call to EPSSetFromOptions()
239:     */
240:     PetscOptionsBool("-eps_monitor_cancel","Remove any hardwired monitor routines","EPSMonitorCancel",PETSC_FALSE,&flg,&set);
241:     if (set && flg) {
242:       EPSMonitorCancel(eps);
243:     }
244:     /*
245:       Text monitors
246:     */
247:     EPSMonitorSetFromOptions(eps,"-eps_monitor","Monitor first unconverged approximate eigenvalue and error estimate","EPSMonitorFirst",EPSMonitorFirst,PETSC_FALSE);
248:     EPSConvMonitorSetFromOptions(eps,"-eps_monitor_conv","Monitor approximate eigenvalues and error estimates as they converge","EPSMonitorConverged",EPSMonitorConverged);
249:     EPSMonitorSetFromOptions(eps,"-eps_monitor_all","Monitor approximate eigenvalues and error estimates","EPSMonitorAll",EPSMonitorAll,PETSC_TRUE);
250:     /*
251:       Line graph monitors
252:     */
253:     PetscOptionsBool("-eps_monitor_lg","Monitor first unconverged approximate eigenvalue and error estimate graphically","EPSMonitorSet",PETSC_FALSE,&flg,&set);
254:     if (set && flg) {
255:       EPSMonitorLGCreate(PetscObjectComm((PetscObject)eps),NULL,"Error estimates",PETSC_DECIDE,PETSC_DECIDE,300,300,&lg);
256:       EPSMonitorSet(eps,EPSMonitorLG,lg,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
257:     }
258:     PetscOptionsBool("-eps_monitor_lg_all","Monitor error estimates graphically","EPSMonitorSet",PETSC_FALSE,&flg,&set);
259:     if (set && flg) {
260:       EPSMonitorLGCreate(PetscObjectComm((PetscObject)eps),NULL,"Error estimates",PETSC_DECIDE,PETSC_DECIDE,300,300,&lg);
261:       EPSMonitorSet(eps,EPSMonitorLGAll,lg,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
262:       EPSSetTrackAll(eps,PETSC_TRUE);
263:     }

265:     /* -----------------------------------------------------------------------*/
266:     PetscOptionsName("-eps_view","Print detailed information on solver used","EPSView",NULL);
267:     PetscOptionsName("-eps_view_vectors","View computed eigenvectors","EPSVectorsView",NULL);
268:     PetscOptionsName("-eps_view_values","View computed eigenvalues","EPSValuesView",NULL);
269:     PetscOptionsName("-eps_converged_reason","Print reason for convergence, and number of iterations","EPSConvergedReasonView",NULL);
270:     PetscOptionsName("-eps_error_absolute","Print absolute errors of each eigenpair","EPSErrorView",NULL);
271:     PetscOptionsName("-eps_error_relative","Print relative errors of each eigenpair","EPSErrorView",NULL);
272:     PetscOptionsName("-eps_error_backward","Print backward errors of each eigenpair","EPSErrorView",NULL);

274:     if (eps->ops->setfromoptions) {
275:       (*eps->ops->setfromoptions)(PetscOptionsObject,eps);
276:     }
277:     PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)eps);
278:   PetscOptionsEnd();

280:   if (!eps->V) { EPSGetBV(eps,&eps->V); }
281:   BVSetFromOptions(eps->V);
282:   if (!eps->rg) { EPSGetRG(eps,&eps->rg); }
283:   RGSetFromOptions(eps->rg);
284:   if (eps->useds) {
285:     if (!eps->ds) { EPSGetDS(eps,&eps->ds); }
286:     DSSetFromOptions(eps->ds);
287:   }
288:   if (!eps->st) { EPSGetST(eps,&eps->st); }
289:   EPSSetDefaultST(eps);
290:   STSetFromOptions(eps->st);
291:   return(0);
292: }

294: /*@C
295:    EPSGetTolerances - Gets the tolerance and maximum iteration count used
296:    by the EPS convergence tests.

298:    Not Collective

300:    Input Parameter:
301: .  eps - the eigensolver context

303:    Output Parameters:
304: +  tol - the convergence tolerance
305: -  maxits - maximum number of iterations

307:    Notes:
308:    The user can specify NULL for any parameter that is not needed.

310:    Level: intermediate

312: .seealso: EPSSetTolerances()
313: @*/
314: PetscErrorCode EPSGetTolerances(EPS eps,PetscReal *tol,PetscInt *maxits)
315: {
318:   if (tol)    *tol    = eps->tol;
319:   if (maxits) *maxits = eps->max_it;
320:   return(0);
321: }

323: /*@
324:    EPSSetTolerances - Sets the tolerance and maximum iteration count used
325:    by the EPS convergence tests.

327:    Logically Collective on eps

329:    Input Parameters:
330: +  eps - the eigensolver context
331: .  tol - the convergence tolerance
332: -  maxits - maximum number of iterations to use

334:    Options Database Keys:
335: +  -eps_tol <tol> - Sets the convergence tolerance
336: -  -eps_max_it <maxits> - Sets the maximum number of iterations allowed

338:    Notes:
339:    Use PETSC_DEFAULT for either argument to assign a reasonably good value.

341:    Level: intermediate

343: .seealso: EPSGetTolerances()
344: @*/
345: PetscErrorCode EPSSetTolerances(EPS eps,PetscReal tol,PetscInt maxits)
346: {
351:   if (tol == PETSC_DEFAULT) {
352:     eps->tol   = PETSC_DEFAULT;
353:     eps->state = EPS_STATE_INITIAL;
354:   } else {
355:     if (tol <= 0.0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
356:     eps->tol = tol;
357:   }
358:   if (maxits == PETSC_DEFAULT || maxits == PETSC_DECIDE) {
359:     eps->max_it = PETSC_DEFAULT;
360:     eps->state  = EPS_STATE_INITIAL;
361:   } else {
362:     if (maxits <= 0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
363:     eps->max_it = maxits;
364:   }
365:   return(0);
366: }

368: /*@C
369:    EPSGetDimensions - Gets the number of eigenvalues to compute
370:    and the dimension of the subspace.

372:    Not Collective

374:    Input Parameter:
375: .  eps - the eigensolver context

377:    Output Parameters:
378: +  nev - number of eigenvalues to compute
379: .  ncv - the maximum dimension of the subspace to be used by the solver
380: -  mpd - the maximum dimension allowed for the projected problem

382:    Level: intermediate

384: .seealso: EPSSetDimensions()
385: @*/
386: PetscErrorCode EPSGetDimensions(EPS eps,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
387: {
390:   if (nev) *nev = eps->nev;
391:   if (ncv) *ncv = eps->ncv;
392:   if (mpd) *mpd = eps->mpd;
393:   return(0);
394: }

396: /*@
397:    EPSSetDimensions - Sets the number of eigenvalues to compute
398:    and the dimension of the subspace.

400:    Logically Collective on eps

402:    Input Parameters:
403: +  eps - the eigensolver context
404: .  nev - number of eigenvalues to compute
405: .  ncv - the maximum dimension of the subspace to be used by the solver
406: -  mpd - the maximum dimension allowed for the projected problem

408:    Options Database Keys:
409: +  -eps_nev <nev> - Sets the number of eigenvalues
410: .  -eps_ncv <ncv> - Sets the dimension of the subspace
411: -  -eps_mpd <mpd> - Sets the maximum projected dimension

413:    Notes:
414:    Use PETSC_DEFAULT for ncv and mpd to assign a reasonably good value, which is
415:    dependent on the solution method.

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

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

426:    When computing all eigenvalues in an interval, see EPSSetInterval(), these
427:    parameters lose relevance, and tuning must be done with
428:    EPSKrylovSchurSetDimensions().

430:    Level: intermediate

432: .seealso: EPSGetDimensions(), EPSSetInterval(), EPSKrylovSchurSetDimensions()
433: @*/
434: PetscErrorCode EPSSetDimensions(EPS eps,PetscInt nev,PetscInt ncv,PetscInt mpd)
435: {
441:   if (nev<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
442:   eps->nev = nev;
443:   if (ncv == PETSC_DECIDE || ncv == PETSC_DEFAULT) {
444:     eps->ncv = PETSC_DEFAULT;
445:   } else {
446:     if (ncv<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
447:     eps->ncv = ncv;
448:   }
449:   if (mpd == PETSC_DECIDE || mpd == PETSC_DEFAULT) {
450:     eps->mpd = PETSC_DEFAULT;
451:   } else {
452:     if (mpd<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
453:     eps->mpd = mpd;
454:   }
455:   eps->state = EPS_STATE_INITIAL;
456:   return(0);
457: }

459: /*@
460:    EPSSetWhichEigenpairs - Specifies which portion of the spectrum is
461:    to be sought.

463:    Logically Collective on eps

465:    Input Parameters:
466: +  eps   - eigensolver context obtained from EPSCreate()
467: -  which - the portion of the spectrum to be sought

469:    Possible values:
470:    The parameter 'which' can have one of these values

472: +     EPS_LARGEST_MAGNITUDE - largest eigenvalues in magnitude (default)
473: .     EPS_SMALLEST_MAGNITUDE - smallest eigenvalues in magnitude
474: .     EPS_LARGEST_REAL - largest real parts
475: .     EPS_SMALLEST_REAL - smallest real parts
476: .     EPS_LARGEST_IMAGINARY - largest imaginary parts
477: .     EPS_SMALLEST_IMAGINARY - smallest imaginary parts
478: .     EPS_TARGET_MAGNITUDE - eigenvalues closest to the target (in magnitude)
479: .     EPS_TARGET_REAL - eigenvalues with real part closest to target
480: .     EPS_TARGET_IMAGINARY - eigenvalues with imaginary part closest to target
481: .     EPS_ALL - all eigenvalues contained in a given interval or region
482: -     EPS_WHICH_USER - user defined ordering set with EPSSetEigenvalueComparison()

484:    Options Database Keys:
485: +   -eps_largest_magnitude - Sets largest eigenvalues in magnitude
486: .   -eps_smallest_magnitude - Sets smallest eigenvalues in magnitude
487: .   -eps_largest_real - Sets largest real parts
488: .   -eps_smallest_real - Sets smallest real parts
489: .   -eps_largest_imaginary - Sets largest imaginary parts
490: .   -eps_smallest_imaginary - Sets smallest imaginary parts
491: .   -eps_target_magnitude - Sets eigenvalues closest to target
492: .   -eps_target_real - Sets real parts closest to target
493: .   -eps_target_imaginary - Sets imaginary parts closest to target
494: -   -eps_all - Sets all eigenvalues in an interval or region

496:    Notes:
497:    Not all eigensolvers implemented in EPS account for all the possible values
498:    stated above. Also, some values make sense only for certain types of
499:    problems. If SLEPc is compiled for real numbers EPS_LARGEST_IMAGINARY
500:    and EPS_SMALLEST_IMAGINARY use the absolute value of the imaginary part
501:    for eigenvalue selection.

503:    The target is a scalar value provided with EPSSetTarget().

505:    The criterion EPS_TARGET_IMAGINARY is available only in case PETSc and
506:    SLEPc have been built with complex scalars.

508:    EPS_ALL is intended for use in combination with an interval (see
509:    EPSSetInterval()), when all eigenvalues within the interval are requested,
510:    or in the context of the CISS solver for computing all eigenvalues in a region.
511:    In those cases, the number of eigenvalues is unknown, so the nev parameter
512:    has a different sense, see EPSSetDimensions().

514:    Level: intermediate

516: .seealso: EPSGetWhichEigenpairs(), EPSSetTarget(), EPSSetInterval(),
517:           EPSSetDimensions(), EPSSetEigenvalueComparison(), EPSWhich
518: @*/
519: PetscErrorCode EPSSetWhichEigenpairs(EPS eps,EPSWhich which)
520: {
524:   switch (which) {
525:     case EPS_LARGEST_MAGNITUDE:
526:     case EPS_SMALLEST_MAGNITUDE:
527:     case EPS_LARGEST_REAL:
528:     case EPS_SMALLEST_REAL:
529:     case EPS_LARGEST_IMAGINARY:
530:     case EPS_SMALLEST_IMAGINARY:
531:     case EPS_TARGET_MAGNITUDE:
532:     case EPS_TARGET_REAL:
533: #if defined(PETSC_USE_COMPLEX)
534:     case EPS_TARGET_IMAGINARY:
535: #endif
536:     case EPS_ALL:
537:     case EPS_WHICH_USER:
538:       if (eps->which != which) {
539:         eps->state = EPS_STATE_INITIAL;
540:         eps->which = which;
541:       }
542:       break;
543: #if !defined(PETSC_USE_COMPLEX)
544:     case EPS_TARGET_IMAGINARY:
545:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"EPS_TARGET_IMAGINARY can be used only with complex scalars");
546: #endif
547:     default:
548:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'which' value");
549:   }
550:   return(0);
551: }

553: /*@
554:    EPSGetWhichEigenpairs - Returns which portion of the spectrum is to be
555:    sought.

557:    Not Collective

559:    Input Parameter:
560: .  eps - eigensolver context obtained from EPSCreate()

562:    Output Parameter:
563: .  which - the portion of the spectrum to be sought

565:    Notes:
566:    See EPSSetWhichEigenpairs() for possible values of 'which'.

568:    Level: intermediate

570: .seealso: EPSSetWhichEigenpairs(), EPSWhich
571: @*/
572: PetscErrorCode EPSGetWhichEigenpairs(EPS eps,EPSWhich *which)
573: {
577:   *which = eps->which;
578:   return(0);
579: }

581: /*@C
582:    EPSSetEigenvalueComparison - Specifies the eigenvalue comparison function
583:    when EPSSetWhichEigenpairs() is set to EPS_WHICH_USER.

585:    Logically Collective on eps

587:    Input Parameters:
588: +  eps  - eigensolver context obtained from EPSCreate()
589: .  func - a pointer to the comparison function
590: -  ctx  - a context pointer (the last parameter to the comparison function)

592:    Calling Sequence of func:
593: $   func(PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *res,void *ctx)

595: +   ar     - real part of the 1st eigenvalue
596: .   ai     - imaginary part of the 1st eigenvalue
597: .   br     - real part of the 2nd eigenvalue
598: .   bi     - imaginary part of the 2nd eigenvalue
599: .   res    - result of comparison
600: -   ctx    - optional context, as set by EPSSetEigenvalueComparison()

602:    Note:
603:    The returning parameter 'res' can be
604: +  negative - if the 1st eigenvalue is preferred to the 2st one
605: .  zero     - if both eigenvalues are equally preferred
606: -  positive - if the 2st eigenvalue is preferred to the 1st one

608:    Level: advanced

610: .seealso: EPSSetWhichEigenpairs(), EPSWhich
611: @*/
612: PetscErrorCode EPSSetEigenvalueComparison(EPS eps,PetscErrorCode (*func)(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*),void* ctx)
613: {
616:   eps->sc->comparison    = func;
617:   eps->sc->comparisonctx = ctx;
618:   eps->which             = EPS_WHICH_USER;
619:   return(0);
620: }

622: /*@C
623:    EPSSetArbitrarySelection - Specifies a function intended to look for
624:    eigenvalues according to an arbitrary selection criterion. This criterion
625:    can be based on a computation involving the current eigenvector approximation.

627:    Logically Collective on eps

629:    Input Parameters:
630: +  eps  - eigensolver context obtained from EPSCreate()
631: .  func - a pointer to the evaluation function
632: -  ctx  - a context pointer (the last parameter to the evaluation function)

634:    Calling Sequence of func:
635: $   func(PetscScalar er,PetscScalar ei,Vec xr,Vec xi,PetscScalar *rr,PetscScalar *ri,void *ctx)

637: +   er     - real part of the current eigenvalue approximation
638: .   ei     - imaginary part of the current eigenvalue approximation
639: .   xr     - real part of the current eigenvector approximation
640: .   xi     - imaginary part of the current eigenvector approximation
641: .   rr     - result of evaluation (real part)
642: .   ri     - result of evaluation (imaginary part)
643: -   ctx    - optional context, as set by EPSSetArbitrarySelection()

645:    Notes:
646:    This provides a mechanism to select eigenpairs by evaluating a user-defined
647:    function. When a function has been provided, the default selection based on
648:    sorting the eigenvalues is replaced by the sorting of the results of this
649:    function (with the same sorting criterion given in EPSSetWhichEigenpairs()).

651:    For instance, suppose you want to compute those eigenvectors that maximize
652:    a certain computable expression. Then implement the computation using
653:    the arguments xr and xi, and return the result in rr. Then set the standard
654:    sorting by magnitude so that the eigenpair with largest value of rr is
655:    selected.

657:    This evaluation function is collective, that is, all processes call it and
658:    it can use collective operations; furthermore, the computed result must
659:    be the same in all processes.

661:    The result of func is expressed as a complex number so that it is possible to
662:    use the standard eigenvalue sorting functions, but normally only rr is used.
663:    Set ri to zero unless it is meaningful in your application.

665:    Level: advanced

667: .seealso: EPSSetWhichEigenpairs()
668: @*/
669: PetscErrorCode EPSSetArbitrarySelection(EPS eps,PetscErrorCode (*func)(PetscScalar,PetscScalar,Vec,Vec,PetscScalar*,PetscScalar*,void*),void* ctx)
670: {
673:   eps->arbitrary    = func;
674:   eps->arbitraryctx = ctx;
675:   eps->state        = EPS_STATE_INITIAL;
676:   return(0);
677: }

679: /*@C
680:    EPSSetConvergenceTestFunction - Sets a function to compute the error estimate
681:    used in the convergence test.

683:    Logically Collective on eps

685:    Input Parameters:
686: +  eps     - eigensolver context obtained from EPSCreate()
687: .  func    - a pointer to the convergence test function
688: .  ctx     - context for private data for the convergence routine (may be null)
689: -  destroy - a routine for destroying the context (may be null)

691:    Calling Sequence of func:
692: $   func(EPS eps,PetscScalar eigr,PetscScalar eigi,PetscReal res,PetscReal *errest,void *ctx)

694: +   eps    - eigensolver context obtained from EPSCreate()
695: .   eigr   - real part of the eigenvalue
696: .   eigi   - imaginary part of the eigenvalue
697: .   res    - residual norm associated to the eigenpair
698: .   errest - (output) computed error estimate
699: -   ctx    - optional context, as set by EPSSetConvergenceTestFunction()

701:    Note:
702:    If the error estimate returned by the convergence test function is less than
703:    the tolerance, then the eigenvalue is accepted as converged.

705:    Level: advanced

707: .seealso: EPSSetConvergenceTest(), EPSSetTolerances()
708: @*/
709: PetscErrorCode EPSSetConvergenceTestFunction(EPS eps,PetscErrorCode (*func)(EPS,PetscScalar,PetscScalar,PetscReal,PetscReal*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
710: {

715:   if (eps->convergeddestroy) {
716:     (*eps->convergeddestroy)(eps->convergedctx);
717:   }
718:   eps->convergeduser    = func;
719:   eps->convergeddestroy = destroy;
720:   eps->convergedctx     = ctx;
721:   if (func == EPSConvergedRelative) eps->conv = EPS_CONV_REL;
722:   else if (func == EPSConvergedNorm) eps->conv = EPS_CONV_NORM;
723:   else if (func == EPSConvergedAbsolute) eps->conv = EPS_CONV_ABS;
724:   else {
725:     eps->conv      = EPS_CONV_USER;
726:     eps->converged = eps->convergeduser;
727:   }
728:   return(0);
729: }

731: /*@
732:    EPSSetConvergenceTest - Specifies how to compute the error estimate
733:    used in the convergence test.

735:    Logically Collective on eps

737:    Input Parameters:
738: +  eps  - eigensolver context obtained from EPSCreate()
739: -  conv - the type of convergence test

741:    Options Database Keys:
742: +  -eps_conv_abs  - Sets the absolute convergence test
743: .  -eps_conv_rel  - Sets the convergence test relative to the eigenvalue
744: .  -eps_conv_norm - Sets the convergence test relative to the matrix norms
745: -  -eps_conv_user - Selects the user-defined convergence test

747:    Note:
748:    The parameter 'conv' can have one of these values
749: +     EPS_CONV_ABS  - absolute error ||r||
750: .     EPS_CONV_REL  - error relative to the eigenvalue l, ||r||/|l|
751: .     EPS_CONV_NORM - error relative to the matrix norms, ||r||/(||A||+|l|*||B||)
752: -     EPS_CONV_USER - function set by EPSSetConvergenceTestFunction()

754:    Level: intermediate

756: .seealso: EPSGetConvergenceTest(), EPSSetConvergenceTestFunction(), EPSSetStoppingTest(), EPSConv
757: @*/
758: PetscErrorCode EPSSetConvergenceTest(EPS eps,EPSConv conv)
759: {
763:   switch (conv) {
764:     case EPS_CONV_ABS:  eps->converged = EPSConvergedAbsolute; break;
765:     case EPS_CONV_REL:  eps->converged = EPSConvergedRelative; break;
766:     case EPS_CONV_NORM: eps->converged = EPSConvergedNorm; break;
767:     case EPS_CONV_USER:
768:       if (!eps->convergeduser) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ORDER,"Must call EPSSetConvergenceTestFunction() first");
769:       eps->converged = eps->convergeduser;
770:       break;
771:     default:
772:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'conv' value");
773:   }
774:   eps->conv = conv;
775:   return(0);
776: }

778: /*@
779:    EPSGetConvergenceTest - Gets the method used to compute the error estimate
780:    used in the convergence test.

782:    Not Collective

784:    Input Parameters:
785: .  eps   - eigensolver context obtained from EPSCreate()

787:    Output Parameters:
788: .  conv  - the type of convergence test

790:    Level: intermediate

792: .seealso: EPSSetConvergenceTest(), EPSConv
793: @*/
794: PetscErrorCode EPSGetConvergenceTest(EPS eps,EPSConv *conv)
795: {
799:   *conv = eps->conv;
800:   return(0);
801: }

803: /*@C
804:    EPSSetStoppingTestFunction - Sets a function to decide when to stop the outer
805:    iteration of the eigensolver.

807:    Logically Collective on eps

809:    Input Parameters:
810: +  eps     - eigensolver context obtained from EPSCreate()
811: .  func    - pointer to the stopping test function
812: .  ctx     - context for private data for the stopping routine (may be null)
813: -  destroy - a routine for destroying the context (may be null)

815:    Calling Sequence of func:
816: $   func(EPS eps,PetscInt its,PetscInt max_it,PetscInt nconv,PetscInt nev,EPSConvergedReason *reason,void *ctx)

818: +   eps    - eigensolver context obtained from EPSCreate()
819: .   its    - current number of iterations
820: .   max_it - maximum number of iterations
821: .   nconv  - number of currently converged eigenpairs
822: .   nev    - number of requested eigenpairs
823: .   reason - (output) result of the stopping test
824: -   ctx    - optional context, as set by EPSSetStoppingTestFunction()

826:    Note:
827:    Normal usage is to first call the default routine EPSStoppingBasic() and then
828:    set reason to EPS_CONVERGED_USER if some user-defined conditions have been
829:    met. To let the eigensolver continue iterating, the result must be left as
830:    EPS_CONVERGED_ITERATING.

832:    Level: advanced

834: .seealso: EPSSetStoppingTest(), EPSStoppingBasic()
835: @*/
836: PetscErrorCode EPSSetStoppingTestFunction(EPS eps,PetscErrorCode (*func)(EPS,PetscInt,PetscInt,PetscInt,PetscInt,EPSConvergedReason*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
837: {

842:   if (eps->stoppingdestroy) {
843:     (*eps->stoppingdestroy)(eps->stoppingctx);
844:   }
845:   eps->stoppinguser    = func;
846:   eps->stoppingdestroy = destroy;
847:   eps->stoppingctx     = ctx;
848:   if (func == EPSStoppingBasic) eps->stop = EPS_STOP_BASIC;
849:   else {
850:     eps->stop     = EPS_STOP_USER;
851:     eps->stopping = eps->stoppinguser;
852:   }
853:   return(0);
854: }

856: /*@
857:    EPSSetStoppingTest - Specifies how to decide the termination of the outer
858:    loop of the eigensolver.

860:    Logically Collective on eps

862:    Input Parameters:
863: +  eps  - eigensolver context obtained from EPSCreate()
864: -  stop - the type of stopping test

866:    Options Database Keys:
867: +  -eps_stop_basic - Sets the default stopping test
868: -  -eps_stop_user  - Selects the user-defined stopping test

870:    Note:
871:    The parameter 'stop' can have one of these values
872: +     EPS_STOP_BASIC - default stopping test
873: -     EPS_STOP_USER  - function set by EPSSetStoppingTestFunction()

875:    Level: advanced

877: .seealso: EPSGetStoppingTest(), EPSSetStoppingTestFunction(), EPSSetConvergenceTest(), EPSStop
878: @*/
879: PetscErrorCode EPSSetStoppingTest(EPS eps,EPSStop stop)
880: {
884:   switch (stop) {
885:     case EPS_STOP_BASIC: eps->stopping = EPSStoppingBasic; break;
886:     case EPS_STOP_USER:
887:       if (!eps->stoppinguser) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ORDER,"Must call EPSSetStoppingTestFunction() first");
888:       eps->stopping = eps->stoppinguser;
889:       break;
890:     default:
891:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'stop' value");
892:   }
893:   eps->stop = stop;
894:   return(0);
895: }

897: /*@
898:    EPSGetStoppingTest - Gets the method used to decide the termination of the outer
899:    loop of the eigensolver.

901:    Not Collective

903:    Input Parameters:
904: .  eps   - eigensolver context obtained from EPSCreate()

906:    Output Parameters:
907: .  stop  - the type of stopping test

909:    Level: advanced

911: .seealso: EPSSetStoppingTest(), EPSStop
912: @*/
913: PetscErrorCode EPSGetStoppingTest(EPS eps,EPSStop *stop)
914: {
918:   *stop = eps->stop;
919:   return(0);
920: }

922: /*@
923:    EPSSetProblemType - Specifies the type of the eigenvalue problem.

925:    Logically Collective on eps

927:    Input Parameters:
928: +  eps      - the eigensolver context
929: -  type     - a known type of eigenvalue problem

931:    Options Database Keys:
932: +  -eps_hermitian - Hermitian eigenvalue problem
933: .  -eps_gen_hermitian - generalized Hermitian eigenvalue problem
934: .  -eps_non_hermitian - non-Hermitian eigenvalue problem
935: .  -eps_gen_non_hermitian - generalized non-Hermitian eigenvalue problem
936: -  -eps_pos_gen_non_hermitian - generalized non-Hermitian eigenvalue problem
937:    with positive semi-definite B

939:    Notes:
940:    Allowed values for the problem type are: Hermitian (EPS_HEP), non-Hermitian
941:    (EPS_NHEP), generalized Hermitian (EPS_GHEP), generalized non-Hermitian
942:    (EPS_GNHEP), generalized non-Hermitian with positive semi-definite B
943:    (EPS_PGNHEP), and generalized Hermitian-indefinite (EPS_GHIEP).

945:    This function must be used to instruct SLEPc to exploit symmetry. If no
946:    problem type is specified, by default a non-Hermitian problem is assumed
947:    (either standard or generalized). If the user knows that the problem is
948:    Hermitian (i.e. A=A^H) or generalized Hermitian (i.e. A=A^H, B=B^H, and
949:    B positive definite) then it is recommended to set the problem type so
950:    that eigensolver can exploit these properties.

952:    Level: intermediate

954: .seealso: EPSSetOperators(), EPSSetType(), EPSGetProblemType(), EPSProblemType
955: @*/
956: PetscErrorCode EPSSetProblemType(EPS eps,EPSProblemType type)
957: {
961:   if (type == eps->problem_type) return(0);
962:   switch (type) {
963:     case EPS_HEP:
964:       eps->isgeneralized = PETSC_FALSE;
965:       eps->ishermitian = PETSC_TRUE;
966:       eps->ispositive = PETSC_FALSE;
967:       break;
968:     case EPS_NHEP:
969:       eps->isgeneralized = PETSC_FALSE;
970:       eps->ishermitian = PETSC_FALSE;
971:       eps->ispositive = PETSC_FALSE;
972:       break;
973:     case EPS_GHEP:
974:       eps->isgeneralized = PETSC_TRUE;
975:       eps->ishermitian = PETSC_TRUE;
976:       eps->ispositive = PETSC_TRUE;
977:       break;
978:     case EPS_GNHEP:
979:       eps->isgeneralized = PETSC_TRUE;
980:       eps->ishermitian = PETSC_FALSE;
981:       eps->ispositive = PETSC_FALSE;
982:       break;
983:     case EPS_PGNHEP:
984:       eps->isgeneralized = PETSC_TRUE;
985:       eps->ishermitian = PETSC_FALSE;
986:       eps->ispositive = PETSC_TRUE;
987:       break;
988:     case EPS_GHIEP:
989:       eps->isgeneralized = PETSC_TRUE;
990:       eps->ishermitian = PETSC_TRUE;
991:       eps->ispositive = PETSC_FALSE;
992:       break;
993:     default:
994:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"Unknown eigenvalue problem type");
995:   }
996:   eps->problem_type = type;
997:   eps->state = EPS_STATE_INITIAL;
998:   return(0);
999: }

1001: /*@
1002:    EPSGetProblemType - Gets the problem type from the EPS object.

1004:    Not Collective

1006:    Input Parameter:
1007: .  eps - the eigensolver context

1009:    Output Parameter:
1010: .  type - the problem type

1012:    Level: intermediate

1014: .seealso: EPSSetProblemType(), EPSProblemType
1015: @*/
1016: PetscErrorCode EPSGetProblemType(EPS eps,EPSProblemType *type)
1017: {
1021:   *type = eps->problem_type;
1022:   return(0);
1023: }

1025: /*@
1026:    EPSSetExtraction - Specifies the type of extraction technique to be employed
1027:    by the eigensolver.

1029:    Logically Collective on eps

1031:    Input Parameters:
1032: +  eps  - the eigensolver context
1033: -  extr - a known type of extraction

1035:    Options Database Keys:
1036: +  -eps_ritz - Rayleigh-Ritz extraction
1037: .  -eps_harmonic - harmonic Ritz extraction
1038: .  -eps_harmonic_relative - harmonic Ritz extraction relative to the eigenvalue
1039: .  -eps_harmonic_right - harmonic Ritz extraction for rightmost eigenvalues
1040: .  -eps_harmonic_largest - harmonic Ritz extraction for largest magnitude
1041:    (without target)
1042: .  -eps_refined - refined Ritz extraction
1043: -  -eps_refined_harmonic - refined harmonic Ritz extraction

1045:    Notes:
1046:    Not all eigensolvers support all types of extraction. See the SLEPc
1047:    Users Manual for details.

1049:    By default, a standard Rayleigh-Ritz extraction is used. Other extractions
1050:    may be useful when computing interior eigenvalues.

1052:    Harmonic-type extractions are used in combination with a 'target'.

1054:    Level: advanced

1056: .seealso: EPSSetTarget(), EPSGetExtraction(), EPSExtraction
1057: @*/
1058: PetscErrorCode EPSSetExtraction(EPS eps,EPSExtraction extr)
1059: {
1063:   eps->extraction = extr;
1064:   return(0);
1065: }

1067: /*@
1068:    EPSGetExtraction - Gets the extraction type used by the EPS object.

1070:    Not Collective

1072:    Input Parameter:
1073: .  eps - the eigensolver context

1075:    Output Parameter:
1076: .  extr - name of extraction type

1078:    Level: advanced

1080: .seealso: EPSSetExtraction(), EPSExtraction
1081: @*/
1082: PetscErrorCode EPSGetExtraction(EPS eps,EPSExtraction *extr)
1083: {
1087:   *extr = eps->extraction;
1088:   return(0);
1089: }

1091: /*@
1092:    EPSSetBalance - Specifies the balancing technique to be employed by the
1093:    eigensolver, and some parameters associated to it.

1095:    Logically Collective on eps

1097:    Input Parameters:
1098: +  eps    - the eigensolver context
1099: .  bal    - the balancing method, one of EPS_BALANCE_NONE, EPS_BALANCE_ONESIDE,
1100:             EPS_BALANCE_TWOSIDE, or EPS_BALANCE_USER
1101: .  its    - number of iterations of the balancing algorithm
1102: -  cutoff - cutoff value

1104:    Options Database Keys:
1105: +  -eps_balance <method> - the balancing method, where <method> is one of
1106:                            'none', 'oneside', 'twoside', or 'user'
1107: .  -eps_balance_its <its> - number of iterations
1108: -  -eps_balance_cutoff <cutoff> - cutoff value

1110:    Notes:
1111:    When balancing is enabled, the solver works implicitly with matrix DAD^-1,
1112:    where D is an appropriate diagonal matrix. This improves the accuracy of
1113:    the computed results in some cases. See the SLEPc Users Manual for details.

1115:    Balancing makes sense only for non-Hermitian problems when the required
1116:    precision is high (i.e. a small tolerance such as 1e-15).

1118:    By default, balancing is disabled. The two-sided method is much more
1119:    effective than the one-sided counterpart, but it requires the system
1120:    matrices to have the MatMultTranspose operation defined.

1122:    The parameter 'its' is the number of iterations performed by the method. The
1123:    cutoff value is used only in the two-side variant. Use PETSC_DEFAULT to assign
1124:    a reasonably good value.

1126:    User-defined balancing is allowed provided that the corresponding matrix
1127:    is set via STSetBalanceMatrix.

1129:    Level: intermediate

1131: .seealso: EPSGetBalance(), EPSBalance, STSetBalanceMatrix()
1132: @*/
1133: PetscErrorCode EPSSetBalance(EPS eps,EPSBalance bal,PetscInt its,PetscReal cutoff)
1134: {
1140:   switch (bal) {
1141:     case EPS_BALANCE_NONE:
1142:     case EPS_BALANCE_ONESIDE:
1143:     case EPS_BALANCE_TWOSIDE:
1144:     case EPS_BALANCE_USER:
1145:       if (eps->balance != bal) {
1146:         eps->state = EPS_STATE_INITIAL;
1147:         eps->balance = bal;
1148:       }
1149:       break;
1150:     default:
1151:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid value of argument 'bal'");
1152:   }
1153:   if (its==PETSC_DECIDE || its==PETSC_DEFAULT) eps->balance_its = 5;
1154:   else {
1155:     if (its <= 0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be > 0");
1156:     eps->balance_its = its;
1157:   }
1158:   if (cutoff==PETSC_DECIDE || cutoff==PETSC_DEFAULT) eps->balance_cutoff = 1e-8;
1159:   else {
1160:     if (cutoff <= 0.0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of cutoff. Must be > 0");
1161:     eps->balance_cutoff = cutoff;
1162:   }
1163:   return(0);
1164: }

1166: /*@C
1167:    EPSGetBalance - Gets the balancing type used by the EPS object, and the
1168:    associated parameters.

1170:    Not Collective

1172:    Input Parameter:
1173: .  eps - the eigensolver context

1175:    Output Parameters:
1176: +  bal    - the balancing method
1177: .  its    - number of iterations of the balancing algorithm
1178: -  cutoff - cutoff value

1180:    Level: intermediate

1182:    Note:
1183:    The user can specify NULL for any parameter that is not needed.

1185: .seealso: EPSSetBalance(), EPSBalance
1186: @*/
1187: PetscErrorCode EPSGetBalance(EPS eps,EPSBalance *bal,PetscInt *its,PetscReal *cutoff)
1188: {
1191:   if (bal)    *bal = eps->balance;
1192:   if (its)    *its = eps->balance_its;
1193:   if (cutoff) *cutoff = eps->balance_cutoff;
1194:   return(0);
1195: }

1197: /*@
1198:    EPSSetTwoSided - Sets the solver to use a two-sided variant so that left
1199:    eigenvectors are also computed.

1201:    Logically Collective on eps

1203:    Input Parameters:
1204: +  eps      - the eigensolver context
1205: -  twosided - whether the two-sided variant is to be used or not

1207:    Options Database Keys:
1208: .  -eps_two_sided <boolean> - Sets/resets the twosided flag

1210:    Notes:
1211:    If the user sets twosided=PETSC_TRUE then the solver uses a variant of
1212:    the algorithm that computes both right and left eigenvectors. This is
1213:    usually much more costly. This option is not available in all solvers.

1215:    When using two-sided solvers, the problem matrices must have both the
1216:    MatMult and MatMultTranspose operations defined.

1218:    Level: advanced

1220: .seealso: EPSGetTwoSided(), EPSGetLeftEigenvector()
1221: @*/
1222: PetscErrorCode EPSSetTwoSided(EPS eps,PetscBool twosided)
1223: {
1227:   if (twosided!=eps->twosided) {
1228:     eps->twosided = twosided;
1229:     eps->state    = EPS_STATE_INITIAL;
1230:   }
1231:   return(0);
1232: }

1234: /*@
1235:    EPSGetTwoSided - Returns the flag indicating whether a two-sided variant
1236:    of the algorithm is being used or not.

1238:    Not Collective

1240:    Input Parameter:
1241: .  eps - the eigensolver context

1243:    Output Parameter:
1244: .  twosided - the returned flag

1246:    Level: advanced

1248: .seealso: EPSSetTwoSided()
1249: @*/
1250: PetscErrorCode EPSGetTwoSided(EPS eps,PetscBool *twosided)
1251: {
1255:   *twosided = eps->twosided;
1256:   return(0);
1257: }

1259: /*@
1260:    EPSSetTrueResidual - Specifies if the solver must compute the true residual
1261:    explicitly or not.

1263:    Logically Collective on eps

1265:    Input Parameters:
1266: +  eps     - the eigensolver context
1267: -  trueres - whether true residuals are required or not

1269:    Options Database Keys:
1270: .  -eps_true_residual <boolean> - Sets/resets the boolean flag 'trueres'

1272:    Notes:
1273:    If the user sets trueres=PETSC_TRUE then the solver explicitly computes
1274:    the true residual for each eigenpair approximation, and uses it for
1275:    convergence testing. Computing the residual is usually an expensive
1276:    operation. Some solvers (e.g., Krylov solvers) can avoid this computation
1277:    by using a cheap estimate of the residual norm, but this may sometimes
1278:    give inaccurate results (especially if a spectral transform is being
1279:    used). On the contrary, preconditioned eigensolvers (e.g., Davidson solvers)
1280:    do rely on computing the true residual, so this option is irrelevant for them.

1282:    Level: advanced

1284: .seealso: EPSGetTrueResidual()
1285: @*/
1286: PetscErrorCode EPSSetTrueResidual(EPS eps,PetscBool trueres)
1287: {
1291:   eps->trueres = trueres;
1292:   return(0);
1293: }

1295: /*@
1296:    EPSGetTrueResidual - Returns the flag indicating whether true
1297:    residuals must be computed explicitly or not.

1299:    Not Collective

1301:    Input Parameter:
1302: .  eps - the eigensolver context

1304:    Output Parameter:
1305: .  trueres - the returned flag

1307:    Level: advanced

1309: .seealso: EPSSetTrueResidual()
1310: @*/
1311: PetscErrorCode EPSGetTrueResidual(EPS eps,PetscBool *trueres)
1312: {
1316:   *trueres = eps->trueres;
1317:   return(0);
1318: }

1320: /*@
1321:    EPSSetTrackAll - Specifies if the solver must compute the residual norm of all
1322:    approximate eigenpairs or not.

1324:    Logically Collective on eps

1326:    Input Parameters:
1327: +  eps      - the eigensolver context
1328: -  trackall - whether to compute all residuals or not

1330:    Notes:
1331:    If the user sets trackall=PETSC_TRUE then the solver computes (or estimates)
1332:    the residual norm for each eigenpair approximation. Computing the residual is
1333:    usually an expensive operation and solvers commonly compute only the residual
1334:    associated to the first unconverged eigenpair.

1336:    The options '-eps_monitor_all' and '-eps_monitor_lg_all' automatically
1337:    activate this option.

1339:    Level: developer

1341: .seealso: EPSGetTrackAll()
1342: @*/
1343: PetscErrorCode EPSSetTrackAll(EPS eps,PetscBool trackall)
1344: {
1348:   eps->trackall = trackall;
1349:   return(0);
1350: }

1352: /*@
1353:    EPSGetTrackAll - Returns the flag indicating whether all residual norms must
1354:    be computed or not.

1356:    Not Collective

1358:    Input Parameter:
1359: .  eps - the eigensolver context

1361:    Output Parameter:
1362: .  trackall - the returned flag

1364:    Level: developer

1366: .seealso: EPSSetTrackAll()
1367: @*/
1368: PetscErrorCode EPSGetTrackAll(EPS eps,PetscBool *trackall)
1369: {
1373:   *trackall = eps->trackall;
1374:   return(0);
1375: }

1377: /*@
1378:    EPSSetPurify - Deactivate eigenvector purification (which is activated by default).

1380:    Logically Collective on eps

1382:    Input Parameters:
1383: +  eps    - the eigensolver context
1384: -  purify - whether purification is required or not

1386:    Options Database Keys:
1387: .  -eps_purify <boolean> - Sets/resets the boolean flag 'purify'

1389:    Notes:
1390:    By default, eigenvectors of generalized symmetric eigenproblems are purified
1391:    in order to purge directions in the nullspace of matrix B. If the user knows
1392:    that B is non-singular, then purification can be safely deactivated and some
1393:    computational cost is avoided (this is particularly important in interval computations).

1395:    Level: intermediate

1397: .seealso: EPSGetPurify(), EPSSetInterval()
1398: @*/
1399: PetscErrorCode EPSSetPurify(EPS eps,PetscBool purify)
1400: {
1404:   if (purify!=eps->purify) {
1405:     eps->purify = purify;
1406:     eps->state  = EPS_STATE_INITIAL;
1407:   }
1408:   return(0);
1409: }

1411: /*@
1412:    EPSGetPurify - Returns the flag indicating whether purification is activated
1413:    or not.

1415:    Not Collective

1417:    Input Parameter:
1418: .  eps - the eigensolver context

1420:    Output Parameter:
1421: .  purify - the returned flag

1423:    Level: intermediate

1425: .seealso: EPSSetPurify()
1426: @*/
1427: PetscErrorCode EPSGetPurify(EPS eps,PetscBool *purify)
1428: {
1432:   *purify = eps->purify;
1433:   return(0);
1434: }

1436: /*@C
1437:    EPSSetOptionsPrefix - Sets the prefix used for searching for all
1438:    EPS options in the database.

1440:    Logically Collective on eps

1442:    Input Parameters:
1443: +  eps - the eigensolver context
1444: -  prefix - the prefix string to prepend to all EPS option requests

1446:    Notes:
1447:    A hyphen (-) must NOT be given at the beginning of the prefix name.
1448:    The first character of all runtime options is AUTOMATICALLY the
1449:    hyphen.

1451:    For example, to distinguish between the runtime options for two
1452:    different EPS contexts, one could call
1453: .vb
1454:       EPSSetOptionsPrefix(eps1,"eig1_")
1455:       EPSSetOptionsPrefix(eps2,"eig2_")
1456: .ve

1458:    Level: advanced

1460: .seealso: EPSAppendOptionsPrefix(), EPSGetOptionsPrefix()
1461: @*/
1462: PetscErrorCode EPSSetOptionsPrefix(EPS eps,const char *prefix)
1463: {

1468:   if (!eps->st) { EPSGetST(eps,&eps->st); }
1469:   STSetOptionsPrefix(eps->st,prefix);
1470:   if (!eps->V) { EPSGetBV(eps,&eps->V); }
1471:   BVSetOptionsPrefix(eps->V,prefix);
1472:   if (!eps->ds) { EPSGetDS(eps,&eps->ds); }
1473:   DSSetOptionsPrefix(eps->ds,prefix);
1474:   if (!eps->rg) { EPSGetRG(eps,&eps->rg); }
1475:   RGSetOptionsPrefix(eps->rg,prefix);
1476:   PetscObjectSetOptionsPrefix((PetscObject)eps,prefix);
1477:   return(0);
1478: }

1480: /*@C
1481:    EPSAppendOptionsPrefix - Appends to the prefix used for searching for all
1482:    EPS options in the database.

1484:    Logically Collective on eps

1486:    Input Parameters:
1487: +  eps - the eigensolver context
1488: -  prefix - the prefix string to prepend to all EPS option requests

1490:    Notes:
1491:    A hyphen (-) must NOT be given at the beginning of the prefix name.
1492:    The first character of all runtime options is AUTOMATICALLY the hyphen.

1494:    Level: advanced

1496: .seealso: EPSSetOptionsPrefix(), EPSGetOptionsPrefix()
1497: @*/
1498: PetscErrorCode EPSAppendOptionsPrefix(EPS eps,const char *prefix)
1499: {

1504:   if (!eps->st) { EPSGetST(eps,&eps->st); }
1505:   STAppendOptionsPrefix(eps->st,prefix);
1506:   if (!eps->V) { EPSGetBV(eps,&eps->V); }
1507:   BVAppendOptionsPrefix(eps->V,prefix);
1508:   if (!eps->ds) { EPSGetDS(eps,&eps->ds); }
1509:   DSAppendOptionsPrefix(eps->ds,prefix);
1510:   if (!eps->rg) { EPSGetRG(eps,&eps->rg); }
1511:   RGAppendOptionsPrefix(eps->rg,prefix);
1512:   PetscObjectAppendOptionsPrefix((PetscObject)eps,prefix);
1513:   return(0);
1514: }

1516: /*@C
1517:    EPSGetOptionsPrefix - Gets the prefix used for searching for all
1518:    EPS options in the database.

1520:    Not Collective

1522:    Input Parameters:
1523: .  eps - the eigensolver context

1525:    Output Parameters:
1526: .  prefix - pointer to the prefix string used is returned

1528:    Note:
1529:    On the Fortran side, the user should pass in a string 'prefix' of
1530:    sufficient length to hold the prefix.

1532:    Level: advanced

1534: .seealso: EPSSetOptionsPrefix(), EPSAppendOptionsPrefix()
1535: @*/
1536: PetscErrorCode EPSGetOptionsPrefix(EPS eps,const char *prefix[])
1537: {

1543:   PetscObjectGetOptionsPrefix((PetscObject)eps,prefix);
1544:   return(0);
1545: }