Actual source code: epsopts.c

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

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

 24:    Input Parameters:
 25: +  eps      - the linear 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: [](ch:eps), `EPSMonitorSet()`, `EPSSetTrackAll()`
 34: @*/
 35: PetscErrorCode EPSMonitorSetFromOptions(EPS eps,const char opt[],const char name[],PetscCtx ctx,PetscBool trackall)
 36: {
 37:   PetscErrorCode       (*mfunc)(EPS,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(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)eps),((PetscObject)eps)->options,((PetscObject)eps)->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(EPSMonitorList,key,&mfunc));
 54:   PetscCheck(mfunc,PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Specified viewer and format not supported");
 55:   PetscCall(PetscFunctionListFind(EPSMonitorCreateList,key,&cfunc));
 56:   PetscCall(PetscFunctionListFind(EPSMonitorDestroyList,key,&dfunc));
 57:   if (!cfunc) cfunc = PetscViewerAndFormatCreate_Internal;
 58:   if (!dfunc) dfunc = PetscViewerAndFormatDestroy;

 60:   PetscCall((*cfunc)(viewer,format,ctx,&vf));
 61:   PetscCall(PetscViewerDestroy(&viewer));
 62:   PetscCall(EPSMonitorSet(eps,mfunc,vf,(PetscCtxDestroyFn*)dfunc));
 63:   if (trackall) PetscCall(EPSSetTrackAll(eps,PETSC_TRUE));
 64:   PetscFunctionReturn(PETSC_SUCCESS);
 65: }

 67: /*@
 68:    EPSSetFromOptions - Sets `EPS` options from the options database.
 69:    This routine must be called before `EPSSetUp()` if the user is to be
 70:    allowed to configure the solver.

 72:    Collective

 74:    Input Parameter:
 75: .  eps - the linear eigensolver context

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

 80:    Level: beginner

 82: .seealso: [](ch:eps), `EPSSetOptionsPrefix()`
 83: @*/
 84: PetscErrorCode EPSSetFromOptions(EPS eps)
 85: {
 86:   char           type[256];
 87:   PetscBool      set,flg,flg1,flg2,flg3,bval;
 88:   PetscReal      r,array[2]={0,0};
 89:   PetscScalar    s;
 90:   PetscInt       i,j,k;
 91:   EPSBalance     bal;

 93:   PetscFunctionBegin;
 95:   PetscCall(EPSRegisterAll());
 96:   PetscObjectOptionsBegin((PetscObject)eps);
 97:     PetscCall(PetscOptionsFList("-eps_type","Eigensolver method","EPSSetType",EPSList,(char*)(((PetscObject)eps)->type_name?((PetscObject)eps)->type_name:EPSKRYLOVSCHUR),type,sizeof(type),&flg));
 98:     if (flg) PetscCall(EPSSetType(eps,type));
 99:     else if (!((PetscObject)eps)->type_name) PetscCall(EPSSetType(eps,EPSKRYLOVSCHUR));

101:     PetscCall(PetscOptionsBoolGroupBegin("-eps_hermitian","Hermitian eigenvalue problem","EPSSetProblemType",&flg));
102:     if (flg) PetscCall(EPSSetProblemType(eps,EPS_HEP));
103:     PetscCall(PetscOptionsBoolGroup("-eps_gen_hermitian","Generalized Hermitian eigenvalue problem","EPSSetProblemType",&flg));
104:     if (flg) PetscCall(EPSSetProblemType(eps,EPS_GHEP));
105:     PetscCall(PetscOptionsBoolGroup("-eps_non_hermitian","Non-Hermitian eigenvalue problem","EPSSetProblemType",&flg));
106:     if (flg) PetscCall(EPSSetProblemType(eps,EPS_NHEP));
107:     PetscCall(PetscOptionsBoolGroup("-eps_gen_non_hermitian","Generalized non-Hermitian eigenvalue problem","EPSSetProblemType",&flg));
108:     if (flg) PetscCall(EPSSetProblemType(eps,EPS_GNHEP));
109:     PetscCall(PetscOptionsBoolGroup("-eps_pos_gen_non_hermitian","Generalized non-Hermitian eigenvalue problem with positive semi-definite B","EPSSetProblemType",&flg));
110:     if (flg) PetscCall(EPSSetProblemType(eps,EPS_PGNHEP));
111:     PetscCall(PetscOptionsBoolGroup("-eps_gen_indefinite","Generalized Hermitian-indefinite eigenvalue problem","EPSSetProblemType",&flg));
112:     if (flg) PetscCall(EPSSetProblemType(eps,EPS_GHIEP));
113:     PetscCall(PetscOptionsBoolGroup("-eps_bse","Structured Bethe-Salpeter eigenvalue problem","EPSSetProblemType",&flg));
114:     if (flg) PetscCall(EPSSetProblemType(eps,EPS_BSE));
115:     PetscCall(PetscOptionsBoolGroup("-eps_hamiltonian","Structured Hamiltonian eigenvalue problem","EPSSetProblemType",&flg));
116:     if (flg) PetscCall(EPSSetProblemType(eps,EPS_HAMILT));
117:     PetscCall(PetscOptionsBoolGroupEnd("-eps_lrep","Structured Linear Response eigenvalue problem","EPSSetProblemType",&flg));
118:     if (flg) PetscCall(EPSSetProblemType(eps,EPS_LREP));

120:     PetscCall(PetscOptionsBoolGroupBegin("-eps_ritz","Rayleigh-Ritz extraction","EPSSetExtraction",&flg));
121:     if (flg) PetscCall(EPSSetExtraction(eps,EPS_RITZ));
122:     PetscCall(PetscOptionsBoolGroup("-eps_harmonic","Harmonic Ritz extraction","EPSSetExtraction",&flg));
123:     if (flg) PetscCall(EPSSetExtraction(eps,EPS_HARMONIC));
124:     PetscCall(PetscOptionsBoolGroup("-eps_harmonic_relative","Relative harmonic Ritz extraction","EPSSetExtraction",&flg));
125:     if (flg) PetscCall(EPSSetExtraction(eps,EPS_HARMONIC_RELATIVE));
126:     PetscCall(PetscOptionsBoolGroup("-eps_harmonic_right","Right harmonic Ritz extraction","EPSSetExtraction",&flg));
127:     if (flg) PetscCall(EPSSetExtraction(eps,EPS_HARMONIC_RIGHT));
128:     PetscCall(PetscOptionsBoolGroup("-eps_harmonic_largest","Largest harmonic Ritz extraction","EPSSetExtraction",&flg));
129:     if (flg) PetscCall(EPSSetExtraction(eps,EPS_HARMONIC_LARGEST));
130:     PetscCall(PetscOptionsBoolGroup("-eps_refined","Refined Ritz extraction","EPSSetExtraction",&flg));
131:     if (flg) PetscCall(EPSSetExtraction(eps,EPS_REFINED));
132:     PetscCall(PetscOptionsBoolGroupEnd("-eps_refined_harmonic","Refined harmonic Ritz extraction","EPSSetExtraction",&flg));
133:     if (flg) PetscCall(EPSSetExtraction(eps,EPS_REFINED_HARMONIC));

135:     bal = eps->balance;
136:     PetscCall(PetscOptionsEnum("-eps_balance","Balancing method","EPSSetBalance",EPSBalanceTypes,(PetscEnum)bal,(PetscEnum*)&bal,&flg1));
137:     j = eps->balance_its;
138:     PetscCall(PetscOptionsInt("-eps_balance_its","Number of iterations in balancing","EPSSetBalance",eps->balance_its,&j,&flg2));
139:     r = eps->balance_cutoff;
140:     PetscCall(PetscOptionsReal("-eps_balance_cutoff","Cutoff value in balancing","EPSSetBalance",eps->balance_cutoff,&r,&flg3));
141:     if (flg1 || flg2 || flg3) PetscCall(EPSSetBalance(eps,bal,j,r));

143:     i = eps->max_it;
144:     PetscCall(PetscOptionsInt("-eps_max_it","Maximum number of iterations","EPSSetTolerances",eps->max_it,&i,&flg1));
145:     r = eps->tol;
146:     PetscCall(PetscOptionsReal("-eps_tol","Tolerance","EPSSetTolerances",SlepcDefaultTol(eps->tol),&r,&flg2));
147:     if (flg1 || flg2) PetscCall(EPSSetTolerances(eps,r,i));

149:     r = eps->thres;
150:     PetscCall(PetscOptionsReal("-eps_threshold_absolute","Absolute threshold","EPSSetThreshold",r,&r,&flg));
151:     if (flg) PetscCall(EPSSetThreshold(eps,r,PETSC_FALSE));
152:     PetscCall(PetscOptionsReal("-eps_threshold_relative","Relative threshold","EPSSetThreshold",r,&r,&flg));
153:     if (flg) PetscCall(EPSSetThreshold(eps,r,PETSC_TRUE));

155:     PetscCall(PetscOptionsBoolGroupBegin("-eps_conv_rel","Relative error convergence test","EPSSetConvergenceTest",&flg));
156:     if (flg) PetscCall(EPSSetConvergenceTest(eps,EPS_CONV_REL));
157:     PetscCall(PetscOptionsBoolGroup("-eps_conv_norm","Convergence test relative to the eigenvalue and the matrix norms","EPSSetConvergenceTest",&flg));
158:     if (flg) PetscCall(EPSSetConvergenceTest(eps,EPS_CONV_NORM));
159:     PetscCall(PetscOptionsBoolGroup("-eps_conv_abs","Absolute error convergence test","EPSSetConvergenceTest",&flg));
160:     if (flg) PetscCall(EPSSetConvergenceTest(eps,EPS_CONV_ABS));
161:     PetscCall(PetscOptionsBoolGroupEnd("-eps_conv_user","User-defined convergence test","EPSSetConvergenceTest",&flg));
162:     if (flg) PetscCall(EPSSetConvergenceTest(eps,EPS_CONV_USER));

164:     PetscCall(PetscOptionsBoolGroupBegin("-eps_stop_basic","Stop iteration if all eigenvalues converged or max_it reached","EPSSetStoppingTest",&flg));
165:     if (flg) PetscCall(EPSSetStoppingTest(eps,EPS_STOP_BASIC));
166:     PetscCall(PetscOptionsBoolGroup("-eps_stop_threshold","Stop iteration if a converged eigenvalue is below/above the threshold","EPSSetStoppingTest",&flg));
167:     if (flg) PetscCall(EPSSetStoppingTest(eps,EPS_STOP_THRESHOLD));
168:     PetscCall(PetscOptionsBoolGroupEnd("-eps_stop_user","User-defined stopping test","EPSSetStoppingTest",&flg));
169:     if (flg) PetscCall(EPSSetStoppingTest(eps,EPS_STOP_USER));

171:     i = eps->nev;
172:     PetscCall(PetscOptionsInt("-eps_nev","Number of eigenvalues to compute","EPSSetDimensions",eps->nev,&i,&flg1));
173:     if (!flg1) i = PETSC_CURRENT;
174:     j = eps->ncv;
175:     PetscCall(PetscOptionsInt("-eps_ncv","Number of basis vectors","EPSSetDimensions",eps->ncv,&j,&flg2));
176:     k = eps->mpd;
177:     PetscCall(PetscOptionsInt("-eps_mpd","Maximum dimension of projected problem","EPSSetDimensions",eps->mpd,&k,&flg3));
178:     if (flg1 || flg2 || flg3) PetscCall(EPSSetDimensions(eps,i,j,k));

180:     PetscCall(PetscOptionsBoolGroupBegin("-eps_largest_magnitude","Compute largest eigenvalues in magnitude","EPSSetWhichEigenpairs",&flg));
181:     if (flg) PetscCall(EPSSetWhichEigenpairs(eps,EPS_LARGEST_MAGNITUDE));
182:     PetscCall(PetscOptionsBoolGroup("-eps_smallest_magnitude","Compute smallest eigenvalues in magnitude","EPSSetWhichEigenpairs",&flg));
183:     if (flg) PetscCall(EPSSetWhichEigenpairs(eps,EPS_SMALLEST_MAGNITUDE));
184:     PetscCall(PetscOptionsBoolGroup("-eps_largest_real","Compute eigenvalues with largest real parts","EPSSetWhichEigenpairs",&flg));
185:     if (flg) PetscCall(EPSSetWhichEigenpairs(eps,EPS_LARGEST_REAL));
186:     PetscCall(PetscOptionsBoolGroup("-eps_smallest_real","Compute eigenvalues with smallest real parts","EPSSetWhichEigenpairs",&flg));
187:     if (flg) PetscCall(EPSSetWhichEigenpairs(eps,EPS_SMALLEST_REAL));
188:     PetscCall(PetscOptionsBoolGroup("-eps_largest_imaginary","Compute eigenvalues with largest imaginary parts","EPSSetWhichEigenpairs",&flg));
189:     if (flg) PetscCall(EPSSetWhichEigenpairs(eps,EPS_LARGEST_IMAGINARY));
190:     PetscCall(PetscOptionsBoolGroup("-eps_smallest_imaginary","Compute eigenvalues with smallest imaginary parts","EPSSetWhichEigenpairs",&flg));
191:     if (flg) PetscCall(EPSSetWhichEigenpairs(eps,EPS_SMALLEST_IMAGINARY));
192:     PetscCall(PetscOptionsBoolGroup("-eps_target_magnitude","Compute eigenvalues closest to target","EPSSetWhichEigenpairs",&flg));
193:     if (flg) PetscCall(EPSSetWhichEigenpairs(eps,EPS_TARGET_MAGNITUDE));
194:     PetscCall(PetscOptionsBoolGroup("-eps_target_real","Compute eigenvalues with real parts closest to target","EPSSetWhichEigenpairs",&flg));
195:     if (flg) PetscCall(EPSSetWhichEigenpairs(eps,EPS_TARGET_REAL));
196:     PetscCall(PetscOptionsBoolGroup("-eps_target_imaginary","Compute eigenvalues with imaginary parts closest to target","EPSSetWhichEigenpairs",&flg));
197:     if (flg) PetscCall(EPSSetWhichEigenpairs(eps,EPS_TARGET_IMAGINARY));
198:     PetscCall(PetscOptionsBoolGroup("-eps_all","Compute all eigenvalues in an interval or a region","EPSSetWhichEigenpairs",&flg));
199:     if (flg) PetscCall(EPSSetWhichEigenpairs(eps,EPS_ALL));
200:     PetscCall(PetscOptionsBoolGroupEnd("-eps_which_user","Select the user-defined selection criterion","EPSSetWhichEigenpairs",&flg));
201:     if (flg) PetscCall(EPSSetWhichEigenpairs(eps,EPS_WHICH_USER));

203:     PetscCall(PetscOptionsScalar("-eps_target","Value of the target","EPSSetTarget",eps->target,&s,&flg));
204:     if (flg) {
205:       if (eps->which!=EPS_TARGET_REAL && eps->which!=EPS_TARGET_IMAGINARY) PetscCall(EPSSetWhichEigenpairs(eps,EPS_TARGET_MAGNITUDE));
206:       PetscCall(EPSSetTarget(eps,s));
207:     }

209:     k = 2;
210:     PetscCall(PetscOptionsRealArray("-eps_interval","Computational interval (two real values separated with a comma without spaces)","EPSSetInterval",array,&k,&flg));
211:     if (flg) {
212:       PetscCheck(k>1,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_SIZ,"Must pass two values in -eps_interval (comma-separated without spaces)");
213:       PetscCall(EPSSetWhichEigenpairs(eps,EPS_ALL));
214:       PetscCall(EPSSetInterval(eps,array[0],array[1]));
215:     }

217:     PetscCall(PetscOptionsBool("-eps_true_residual","Compute true residuals explicitly","EPSSetTrueResidual",eps->trueres,&eps->trueres,NULL));
218:     PetscCall(PetscOptionsBool("-eps_purify","Postprocess eigenvectors for purification","EPSSetPurify",eps->purify,&bval,&flg));
219:     if (flg) PetscCall(EPSSetPurify(eps,bval));
220:     PetscCall(PetscOptionsBool("-eps_two_sided","Use two-sided variant (to compute left eigenvectors)","EPSSetTwoSided",eps->twosided,&bval,&flg));
221:     if (flg) PetscCall(EPSSetTwoSided(eps,bval));

223:     /* -----------------------------------------------------------------------*/
224:     /*
225:       Cancels all monitors hardwired into code before call to EPSSetFromOptions()
226:     */
227:     PetscCall(PetscOptionsBool("-eps_monitor_cancel","Remove any hardwired monitor routines","EPSMonitorCancel",PETSC_FALSE,&flg,&set));
228:     if (set && flg) PetscCall(EPSMonitorCancel(eps));
229:     PetscCall(EPSMonitorSetFromOptions(eps,"-eps_monitor","first_approximation",NULL,PETSC_FALSE));
230:     PetscCall(EPSMonitorSetFromOptions(eps,"-eps_monitor_all","all_approximations",NULL,PETSC_TRUE));
231:     PetscCall(EPSMonitorSetFromOptions(eps,"-eps_monitor_conv","convergence_history",NULL,PETSC_FALSE));

233:     /* -----------------------------------------------------------------------*/
234:     PetscCall(PetscOptionsName("-eps_view","Print detailed information on solver used","EPSView",&set));
235:     PetscCall(PetscOptionsName("-eps_view_vectors","View computed eigenvectors","EPSVectorsView",&set));
236:     PetscCall(PetscOptionsName("-eps_view_values","View computed eigenvalues","EPSValuesView",&set));
237:     PetscCall(PetscOptionsName("-eps_converged_reason","Print reason for convergence, and number of iterations","EPSConvergedReasonView",&set));
238:     PetscCall(PetscOptionsName("-eps_error_absolute","Print absolute errors of each eigenpair","EPSErrorView",&set));
239:     PetscCall(PetscOptionsName("-eps_error_relative","Print relative errors of each eigenpair","EPSErrorView",&set));
240:     PetscCall(PetscOptionsName("-eps_error_backward","Print backward errors of each eigenpair","EPSErrorView",&set));

242:     PetscTryTypeMethod(eps,setfromoptions,PetscOptionsObject);
243:     PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)eps,PetscOptionsObject));
244:   PetscOptionsEnd();

246:   if (!eps->V) PetscCall(EPSGetBV(eps,&eps->V));
247:   PetscCall(BVSetFromOptions(eps->V));
248:   if (!eps->rg) PetscCall(EPSGetRG(eps,&eps->rg));
249:   PetscCall(RGSetFromOptions(eps->rg));
250:   if (eps->useds) {
251:     if (!eps->ds) PetscCall(EPSGetDS(eps,&eps->ds));
252:     PetscCall(EPSSetDSType(eps));
253:     PetscCall(DSSetFromOptions(eps->ds));
254:   }
255:   if (!eps->st) PetscCall(EPSGetST(eps,&eps->st));
256:   PetscCall(EPSSetDefaultST(eps));
257:   PetscCall(STSetFromOptions(eps->st));
258:   PetscFunctionReturn(PETSC_SUCCESS);
259: }

261: /*@
262:    EPSGetTolerances - Gets the tolerance and maximum iteration count used
263:    by the `EPS` convergence tests.

265:    Not Collective

267:    Input Parameter:
268: .  eps - the linear eigensolver context

270:    Output Parameters:
271: +  tol - the convergence tolerance
272: -  maxits - maximum number of iterations

274:    Notes:
275:    The user can specify `NULL` for any parameter that is not needed.

277:    Level: intermediate

279: .seealso: [](ch:eps), `EPSSetTolerances()`
280: @*/
281: PetscErrorCode EPSGetTolerances(EPS eps,PetscReal *tol,PetscInt *maxits)
282: {
283:   PetscFunctionBegin;
285:   if (tol)    *tol    = eps->tol;
286:   if (maxits) *maxits = eps->max_it;
287:   PetscFunctionReturn(PETSC_SUCCESS);
288: }

290: /*@
291:    EPSSetTolerances - Sets the tolerance and maximum iteration count used
292:    by the `EPS` convergence tests.

294:    Logically Collective

296:    Input Parameters:
297: +  eps    - the linear eigensolver context
298: .  tol    - the convergence tolerance
299: -  maxits - maximum number of iterations to use

301:    Options Database Keys:
302: +  -eps_tol tol       - sets the convergence tolerance
303: -  -eps_max_it maxits - sets the maximum number of iterations allowed

305:    Note:
306:    Use `PETSC_CURRENT` to retain the current value of any of the parameters.
307:    Use `PETSC_DETERMINE` for either argument to assign a default value computed
308:    internally (may be different in each solver).
309:    For `maxits` use `PETSC_UNLIMITED` to indicate there is no upper bound on this value.

311:    Level: intermediate

313: .seealso: [](ch:eps), `EPSGetTolerances()`
314: @*/
315: PetscErrorCode EPSSetTolerances(EPS eps,PetscReal tol,PetscInt maxits)
316: {
317:   PetscFunctionBegin;
321:   if (tol == (PetscReal)PETSC_DETERMINE) {
322:     eps->tol   = PETSC_DETERMINE;
323:     eps->state = EPS_STATE_INITIAL;
324:   } else if (tol != (PetscReal)PETSC_CURRENT) {
325:     PetscCheck(tol>0.0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
326:     eps->tol = tol;
327:   }
328:   if (maxits == PETSC_DETERMINE) {
329:     eps->max_it = PETSC_DETERMINE;
330:     eps->state  = EPS_STATE_INITIAL;
331:   } else if (maxits == PETSC_UNLIMITED) {
332:     eps->max_it = PETSC_INT_MAX;
333:   } else if (maxits != PETSC_CURRENT) {
334:     PetscCheck(maxits>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
335:     eps->max_it = maxits;
336:   }
337:   PetscFunctionReturn(PETSC_SUCCESS);
338: }

340: /*@
341:    EPSGetDimensions - Gets the number of eigenvalues to compute
342:    and the dimension of the subspace.

344:    Not Collective

346:    Input Parameter:
347: .  eps - the linear eigensolver context

349:    Output Parameters:
350: +  nev - number of eigenvalues to compute
351: .  ncv - the maximum dimension of the subspace to be used by the solver
352: -  mpd - the maximum dimension allowed for the projected problem

354:    Level: intermediate

356: .seealso: [](ch:eps), `EPSSetDimensions()`
357: @*/
358: PetscErrorCode EPSGetDimensions(EPS eps,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
359: {
360:   PetscFunctionBegin;
362:   if (nev) *nev = eps->nev? eps->nev: 1;
363:   if (ncv) *ncv = eps->ncv;
364:   if (mpd) *mpd = eps->mpd;
365:   PetscFunctionReturn(PETSC_SUCCESS);
366: }

368: /*@
369:    EPSSetDimensions - Sets the number of eigenvalues to compute
370:    and the dimension of the subspace.

372:    Logically Collective

374:    Input Parameters:
375: +  eps - the linear eigensolver context
376: .  nev - number of eigenvalues to compute
377: .  ncv - the maximum dimension of the subspace to be used by the solver
378: -  mpd - the maximum dimension allowed for the projected problem

380:    Options Database Keys:
381: +  -eps_nev nev - sets the number of eigenvalues
382: .  -eps_ncv ncv - sets the dimension of the subspace
383: -  -eps_mpd mpd - sets the maximum projected dimension

385:    Notes:
386:    Use `PETSC_DETERMINE` for `ncv` and `mpd` to assign a reasonably good value, which is
387:    dependent on the solution method. For any of the arguments, use `PETSC_CURRENT`
388:    to preserve the current value.

390:    The parameters `ncv` and `mpd` are intimately related, so that the user is advised
391:    to set one of them at most. Normal usage is\:

393:     1. In cases where `nev` is small, the user sets `ncv` (a reasonable default is `2*nev`).
394:     2. In cases where `nev` is large, the user sets `mpd`.

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

400:    When computing all eigenvalues in an interval, see `EPSSetInterval()`, these
401:    parameters lose relevance, and tuning must be done with
402:    `EPSKrylovSchurSetDimensions()`.

404:    Level: intermediate

406: .seealso: [](ch:eps), `EPSGetDimensions()`, `EPSSetInterval()`, `EPSKrylovSchurSetDimensions()`
407: @*/
408: PetscErrorCode EPSSetDimensions(EPS eps,PetscInt nev,PetscInt ncv,PetscInt mpd)
409: {
410:   PetscFunctionBegin;
415:   if (nev != PETSC_CURRENT) {
416:     PetscCheck(nev>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
417:     eps->nev = nev;
418:   }
419:   if (ncv == PETSC_DETERMINE) {
420:     eps->ncv = PETSC_DETERMINE;
421:   } else if (ncv != PETSC_CURRENT) {
422:     PetscCheck(ncv>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
423:     eps->ncv = ncv;
424:   }
425:   if (mpd == PETSC_DETERMINE) {
426:     eps->mpd = PETSC_DETERMINE;
427:   } else if (mpd != PETSC_CURRENT) {
428:     PetscCheck(mpd>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
429:     eps->mpd = mpd;
430:   }
431:   eps->state = EPS_STATE_INITIAL;
432:   PetscFunctionReturn(PETSC_SUCCESS);
433: }

435: /*@
436:    EPSSetWhichEigenpairs - Specifies which portion of the spectrum is
437:    to be sought.

439:    Logically Collective

441:    Input Parameters:
442: +  eps   - the linear eigensolver context
443: -  which - the portion of the spectrum to be sought, see `EPSWhich` for possible values

445:    Options Database Keys:
446: +  -eps_largest_magnitude  - sets largest eigenvalues in magnitude
447: .  -eps_smallest_magnitude - sets smallest eigenvalues in magnitude
448: .  -eps_largest_real       - sets largest real parts
449: .  -eps_smallest_real      - sets smallest real parts
450: .  -eps_largest_imaginary  - sets largest imaginary parts
451: .  -eps_smallest_imaginary - sets smallest imaginary parts
452: .  -eps_target_magnitude   - sets eigenvalues closest to target
453: .  -eps_target_real        - sets real parts closest to target
454: .  -eps_target_imaginary   - sets imaginary parts closest to target
455: .  -eps_all                - sets all eigenvalues in an interval or region
456: -  -eps_which_user         - select the user-defined selection criterion

458:    Notes:
459:    Not all eigensolvers implemented in `EPS` account for all the possible values
460:    of `which`. Also, some values make sense only for certain types of
461:    problems. If SLEPc is compiled for real numbers `EPS_LARGEST_IMAGINARY`
462:    and `EPS_SMALLEST_IMAGINARY` use the absolute value of the imaginary part
463:    for eigenvalue selection.

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

467:    The criterion `EPS_TARGET_IMAGINARY` is available only in case PETSc and
468:    SLEPc have been built with complex scalars.

470:    `EPS_ALL` is intended for use in combination with an interval (see
471:    `EPSSetInterval()`), when all eigenvalues within the interval are requested,
472:    or in the context of the `EPSCISS` solver for computing all eigenvalues in a region.

474:    Level: intermediate

476: .seealso: [](ch:eps), `EPSGetWhichEigenpairs()`, `EPSSetTarget()`, `EPSSetInterval()`, `EPSSetDimensions()`, `EPSSetEigenvalueComparison()`, `EPSWhich`
477: @*/
478: PetscErrorCode EPSSetWhichEigenpairs(EPS eps,EPSWhich which)
479: {
480:   PetscFunctionBegin;
483:   switch (which) {
484:     case EPS_LARGEST_MAGNITUDE:
485:     case EPS_SMALLEST_MAGNITUDE:
486:     case EPS_LARGEST_REAL:
487:     case EPS_SMALLEST_REAL:
488:     case EPS_LARGEST_IMAGINARY:
489:     case EPS_SMALLEST_IMAGINARY:
490:     case EPS_TARGET_MAGNITUDE:
491:     case EPS_TARGET_REAL:
492: #if defined(PETSC_USE_COMPLEX)
493:     case EPS_TARGET_IMAGINARY:
494: #endif
495:     case EPS_ALL:
496:     case EPS_WHICH_USER:
497:       if (eps->which != which) {
498:         eps->state = EPS_STATE_INITIAL;
499:         eps->which = which;
500:       }
501:       break;
502: #if !defined(PETSC_USE_COMPLEX)
503:     case EPS_TARGET_IMAGINARY:
504:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"EPS_TARGET_IMAGINARY can be used only with complex scalars");
505: #endif
506:     default:
507:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'which' value");
508:   }
509:   PetscFunctionReturn(PETSC_SUCCESS);
510: }

512: /*@
513:    EPSGetWhichEigenpairs - Returns which portion of the spectrum is to be
514:    sought.

516:    Not Collective

518:    Input Parameter:
519: .  eps - the linear eigensolver context

521:    Output Parameter:
522: .  which - the portion of the spectrum to be sought, see `EPSWhich` for possible values

524:    Level: intermediate

526: .seealso: [](ch:eps), `EPSSetWhichEigenpairs()`, `EPSWhich`
527: @*/
528: PetscErrorCode EPSGetWhichEigenpairs(EPS eps,EPSWhich *which)
529: {
530:   PetscFunctionBegin;
532:   PetscAssertPointer(which,2);
533:   *which = eps->which;
534:   PetscFunctionReturn(PETSC_SUCCESS);
535: }

537: /*@
538:    EPSSetThreshold - Sets the threshold used in the threshold stopping test.

540:    Logically Collective

542:    Input Parameters:
543: +  eps   - the linear eigensolver context
544: .  thres - the threshold value
545: -  rel   - whether the threshold is relative or not

547:    Options Database Keys:
548: +  -eps_threshold_absolute thres - sets an absolute threshold
549: -  -eps_threshold_relative thres - sets a relative threshold

551:    Notes:
552:    This function internally calls `EPSSetStoppingTest()` to set a special stopping
553:    test based on the threshold, where eigenvalues are computed in sequence until
554:    one of the computed eigenvalues is below the threshold `thres` (in magnitude).
555:    This is the interpretation in case of searching for largest eigenvalues in magnitude,
556:    see `EPSSetWhichEigenpairs()`.

558:    If the solver is configured to compute smallest magnitude eigenvalues, then the
559:    threshold must be interpreted in the opposite direction, i.e., the computation
560:    will stop when one of the computed values is above the threshold (in magnitude).

562:    The threshold can also be used when computing largest/smallest real eigenvalues
563:    (i.e, rightmost or leftmost), in which case the threshold is allowed to be
564:    negative. The solver will stop when one of the computed eigenvalues is above
565:    or below the threshold (considering the real part of the eigenvalue). This mode
566:    is allowed only in problem types whose eigenvalues are always real (e.g., `EPS_HEP`).

568:    In the case of largest magnitude eigenvalues, the threshold can be made relative
569:    with respect to the dominant eigenvalue. Otherwise, the argument `rel` should be
570:    `PETSC_FALSE`.

572:    An additional use case is with target magnitude selection of eigenvalues (e.g.,
573:    with shift-and-invert), but this must be used with caution to avoid unexpected
574:    behavior. With an absolute threshold, the solver will assume that leftmost
575:    eigenvalues are being computed (e.g., with `target`=0 for a problem with real
576:    positive eigenvalues). In case of a relative threshold, a value of `thres`<1
577:    implies that the wanted eigenvalues are the largest ones, and otherwise the
578:    solver assumes that smallest eigenvalues are being computed.

580:    The test against the threshold is done for converged eigenvalues, which
581:    implies that the final number of converged eigenvalues will be at least
582:    one more than the actual number of values below/above the threshold.

584:    Since the number of computed eigenvalues is not known a priori, the solver
585:    will need to reallocate the basis of vectors internally, to have enough room
586:    to accommodate all the eigenvectors. Hence, this option must be used with
587:    caution to avoid out-of-memory problems. The recommendation is to set the value
588:    of `ncv` to be larger than the estimated number of eigenvalues, to minimize the
589:    number of reallocations.

591:    If a number of wanted eigenvalues has been set with `EPSSetDimensions()`
592:    it is also taken into account and the solver will stop when one of the two
593:    conditions (threshold or number of converged values) is met.

595:    Use `EPSSetStoppingTest()` to return to the usual computation of a fixed number
596:    of eigenvalues.

598:    Level: advanced

600: .seealso: [](ch:eps), `EPSGetThreshold()`, `EPSSetStoppingTest()`, `EPSSetDimensions()`, `EPSSetWhichEigenpairs()`, `EPSSetProblemType()`
601: @*/
602: PetscErrorCode EPSSetThreshold(EPS eps,PetscReal thres,PetscBool rel)
603: {
604:   PetscFunctionBegin;
608:   if (eps->thres != thres || eps->threlative != rel) {
609:     eps->thres = thres;
610:     eps->threlative = rel;
611:     eps->state = EPS_STATE_INITIAL;
612:     PetscCall(EPSSetStoppingTest(eps,EPS_STOP_THRESHOLD));
613:   }
614:   PetscFunctionReturn(PETSC_SUCCESS);
615: }

617: /*@
618:    EPSGetThreshold - Gets the threshold used by the threshold stopping test.

620:    Not Collective

622:    Input Parameter:
623: .  eps - the linear eigensolver context

625:    Output Parameters:
626: +  thres - the threshold
627: -  rel   - whether the threshold is relative or not

629:    Level: advanced

631: .seealso: [](ch:eps), `EPSSetThreshold()`
632: @*/
633: PetscErrorCode EPSGetThreshold(EPS eps,PetscReal *thres,PetscBool *rel)
634: {
635:   PetscFunctionBegin;
637:   if (thres) *thres = eps->thres;
638:   if (rel)   *rel   = eps->threlative;
639:   PetscFunctionReturn(PETSC_SUCCESS);
640: }

642: /*@C
643:    EPSSetEigenvalueComparison - Specifies the eigenvalue comparison function
644:    when `EPSSetWhichEigenpairs()` is set to `EPS_WHICH_USER`.

646:    Logically Collective

648:    Input Parameters:
649: +  eps  - the linear eigensolver context
650: .  func - the comparison function, see `SlepcEigenvalueComparisonFn` for the calling sequence
651: -  ctx  - a context pointer (the last parameter to the comparison function)

653:    Level: advanced

655: .seealso: [](ch:eps), `EPSSetWhichEigenpairs()`, `EPSWhich`
656: @*/
657: PetscErrorCode EPSSetEigenvalueComparison(EPS eps,SlepcEigenvalueComparisonFn *func,PetscCtx ctx)
658: {
659:   PetscFunctionBegin;
661:   eps->sc->comparison    = func;
662:   eps->sc->comparisonctx = ctx;
663:   eps->which             = EPS_WHICH_USER;
664:   PetscFunctionReturn(PETSC_SUCCESS);
665: }

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

672:    Logically Collective

674:    Input Parameters:
675: +  eps  - the linear eigensolver context
676: .  func - the arbitrary selection function, see `SlepcArbitrarySelectionFn` for a calling sequence
677: -  ctx  - a context pointer (the last parameter to the arbitrary selection function)

679:    Notes:
680:    This provides a mechanism to select eigenpairs by evaluating a user-defined
681:    function. When a function has been provided, the default selection based on
682:    sorting the eigenvalues is replaced by the sorting of the results of this
683:    function (with the same sorting criterion given in `EPSSetWhichEigenpairs()`).

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

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

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

699:    Level: advanced

701: .seealso: [](ch:eps), `EPSSetWhichEigenpairs()`, `EPSSetArbitrarySelectionContextDestroy()`
702: @*/
703: PetscErrorCode EPSSetArbitrarySelection(EPS eps,SlepcArbitrarySelectionFn *func,PetscCtx ctx)
704: {
705:   PetscFunctionBegin;
707:   if (eps->arbitrarydestroy) PetscCall((*eps->arbitrarydestroy)(&eps->arbitraryctx));
708:   eps->arbitrary    = func;
709:   eps->arbitraryctx = ctx;
710:   eps->state        = EPS_STATE_INITIAL;
711:   PetscFunctionReturn(PETSC_SUCCESS);
712: }

714: /*@C
715:    EPSSetArbitrarySelectionContextDestroy - Set a context destroy function for the
716:    context used in the arbitrary selection.

718:    Logically Collective

720:    Input Parameters:
721: +  eps     - the linear eigensolver context
722: -  destroy - context destroy function, see `PetscCtxDestroyFn` for its calling sequence

724:    Level: advanced

726: .seealso: [](ch:eps), `EPSSetArbitrarySelection()`
727: @*/
728: PetscErrorCode EPSSetArbitrarySelectionContextDestroy(EPS eps,PetscCtxDestroyFn *destroy)
729: {
730:   PetscFunctionBegin;
732:   eps->arbitrarydestroy = destroy;
733:   PetscFunctionReturn(PETSC_SUCCESS);
734: }

736: /*@C
737:    EPSSetConvergenceTestFunction - Sets a function to compute the error estimate
738:    used in the convergence test.

740:    Logically Collective

742:    Input Parameters:
743: +  eps     - the linear eigensolver context
744: .  func    - convergence test function, see `EPSConvergenceTestFn` for the calling sequence
745: .  ctx     - context for private data for the convergence routine (may be `NULL`)
746: -  destroy - a routine for destroying the context (may be `NULL`), see `PetscCtxDestroyFn`
747:              for the calling sequence

749:    Notes:
750:    When this is called with a user-defined function, then the convergence
751:    criterion is set to `EPS_CONV_USER`, see `EPSSetConvergenceTest()`.

753:    If the error estimate returned by the convergence test function is less than
754:    the tolerance, then the eigenvalue is accepted as converged.

756:    Level: advanced

758: .seealso: [](ch:eps), `EPSSetConvergenceTest()`, `EPSSetTolerances()`
759: @*/
760: PetscErrorCode EPSSetConvergenceTestFunction(EPS eps,EPSConvergenceTestFn *func,PetscCtx ctx,PetscCtxDestroyFn *destroy)
761: {
762:   PetscFunctionBegin;
764:   if (eps->convergeddestroy) PetscCall((*eps->convergeddestroy)(&eps->convergedctx));
765:   eps->convergeduser    = func;
766:   eps->convergeddestroy = destroy;
767:   eps->convergedctx     = ctx;
768:   if (func == EPSConvergedRelative) eps->conv = EPS_CONV_REL;
769:   else if (func == EPSConvergedNorm) eps->conv = EPS_CONV_NORM;
770:   else if (func == EPSConvergedAbsolute) eps->conv = EPS_CONV_ABS;
771:   else {
772:     eps->conv      = EPS_CONV_USER;
773:     eps->converged = eps->convergeduser;
774:   }
775:   PetscFunctionReturn(PETSC_SUCCESS);
776: }

778: /*@
779:    EPSSetConvergenceTest - Specifies how to compute the error estimate
780:    used in the convergence test.

782:    Logically Collective

784:    Input Parameters:
785: +  eps  - the linear eigensolver context
786: -  conv - the type of convergence test, see `EPSConv` for possible values

788:    Options Database Keys:
789: +  -eps_conv_abs  - sets the absolute convergence test
790: .  -eps_conv_rel  - sets the convergence test relative to the eigenvalue
791: .  -eps_conv_norm - sets the convergence test relative to the matrix norms
792: -  -eps_conv_user - selects the user-defined convergence test

794:    Level: intermediate

796: .seealso: [](ch:eps), `EPSGetConvergenceTest()`, `EPSSetConvergenceTestFunction()`, `EPSSetStoppingTest()`, `EPSConv`
797: @*/
798: PetscErrorCode EPSSetConvergenceTest(EPS eps,EPSConv conv)
799: {
800:   PetscFunctionBegin;
803:   switch (conv) {
804:     case EPS_CONV_ABS:  eps->converged = EPSConvergedAbsolute; break;
805:     case EPS_CONV_REL:  eps->converged = EPSConvergedRelative; break;
806:     case EPS_CONV_NORM: eps->converged = EPSConvergedNorm; break;
807:     case EPS_CONV_USER:
808:       PetscCheck(eps->convergeduser,PetscObjectComm((PetscObject)eps),PETSC_ERR_ORDER,"Must call EPSSetConvergenceTestFunction() first");
809:       eps->converged = eps->convergeduser;
810:       break;
811:     default:
812:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'conv' value");
813:   }
814:   eps->conv = conv;
815:   PetscFunctionReturn(PETSC_SUCCESS);
816: }

818: /*@
819:    EPSGetConvergenceTest - Gets the method used to compute the error estimate
820:    used in the convergence test.

822:    Not Collective

824:    Input Parameter:
825: .  eps   - the linear eigensolver context

827:    Output Parameter:
828: .  conv  - the type of convergence test

830:    Level: intermediate

832: .seealso: [](ch:eps), `EPSSetConvergenceTest()`, `EPSConv`
833: @*/
834: PetscErrorCode EPSGetConvergenceTest(EPS eps,EPSConv *conv)
835: {
836:   PetscFunctionBegin;
838:   PetscAssertPointer(conv,2);
839:   *conv = eps->conv;
840:   PetscFunctionReturn(PETSC_SUCCESS);
841: }

843: /*@C
844:    EPSSetStoppingTestFunction - Sets a function to decide when to stop the outer
845:    iteration of the eigensolver.

847:    Logically Collective

849:    Input Parameters:
850: +  eps     - the linear eigensolver context
851: .  func    - stopping test function, see `EPSStoppingTestFn` for the calling sequence
852: .  ctx     - context for private data for the stopping routine (may be `NULL`)
853: -  destroy - a routine for destroying the context (may be `NULL`), see `PetscCtxDestroyFn`
854:              for the calling sequence

856:    Note:
857:    When implementing a function for this, normal usage is to first call the
858:    default routine `EPSStoppingBasic()` and then set `reason` to `EPS_CONVERGED_USER`
859:    if some user-defined conditions have been met. To let the eigensolver continue
860:    iterating, the result must be left as `EPS_CONVERGED_ITERATING`.

862:    Level: advanced

864: .seealso: [](ch:eps), `EPSSetStoppingTest()`, `EPSStoppingBasic()`
865: @*/
866: PetscErrorCode EPSSetStoppingTestFunction(EPS eps,EPSStoppingTestFn *func,PetscCtx ctx,PetscCtxDestroyFn *destroy)
867: {
868:   PetscFunctionBegin;
870:   if (eps->stoppingdestroy) PetscCall((*eps->stoppingdestroy)(&eps->stoppingctx));
871:   eps->stoppinguser    = func;
872:   eps->stoppingdestroy = destroy;
873:   eps->stoppingctx     = ctx;
874:   if (func == EPSStoppingBasic) PetscCall(EPSSetStoppingTest(eps,EPS_STOP_BASIC));
875:   else if (func == EPSStoppingThreshold) PetscCall(EPSSetStoppingTest(eps,EPS_STOP_THRESHOLD));
876:   else {
877:     eps->stop     = EPS_STOP_USER;
878:     eps->stopping = eps->stoppinguser;
879:   }
880:   PetscFunctionReturn(PETSC_SUCCESS);
881: }

883: /*@
884:    EPSSetStoppingTest - Specifies how to decide the termination of the outer
885:    loop of the eigensolver.

887:    Logically Collective

889:    Input Parameters:
890: +  eps  - the linear eigensolver context
891: -  stop - the type of stopping test, see `EPSStop`

893:    Options Database Keys:
894: +  -eps_stop_basic     - sets the default stopping test
895: .  -eps_stop_threshold - sets the threshold stopping test
896: -  -eps_stop_user      - selects the user-defined stopping test

898:    Level: advanced

900: .seealso: [](ch:eps), `EPSGetStoppingTest()`, `EPSSetStoppingTestFunction()`, `EPSSetConvergenceTest()`, `EPSStop`
901: @*/
902: PetscErrorCode EPSSetStoppingTest(EPS eps,EPSStop stop)
903: {
904:   PetscFunctionBegin;
907:   switch (stop) {
908:     case EPS_STOP_BASIC: eps->stopping = EPSStoppingBasic; break;
909:     case EPS_STOP_THRESHOLD: eps->stopping = EPSStoppingThreshold; break;
910:     case EPS_STOP_USER:
911:       PetscCheck(eps->stoppinguser,PetscObjectComm((PetscObject)eps),PETSC_ERR_ORDER,"Must call EPSSetStoppingTestFunction() first");
912:       eps->stopping = eps->stoppinguser;
913:       break;
914:     default:
915:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'stop' value");
916:   }
917:   eps->stop = stop;
918:   PetscFunctionReturn(PETSC_SUCCESS);
919: }

921: /*@
922:    EPSGetStoppingTest - Gets the method used to decide the termination of the outer
923:    loop of the eigensolver.

925:    Not Collective

927:    Input Parameter:
928: .  eps   - the linear eigensolver context

930:    Output Parameter:
931: .  stop  - the type of stopping test

933:    Level: advanced

935: .seealso: [](ch:eps), `EPSSetStoppingTest()`, `EPSStop`
936: @*/
937: PetscErrorCode EPSGetStoppingTest(EPS eps,EPSStop *stop)
938: {
939:   PetscFunctionBegin;
941:   PetscAssertPointer(stop,2);
942:   *stop = eps->stop;
943:   PetscFunctionReturn(PETSC_SUCCESS);
944: }

946: /*@
947:    EPSSetProblemType - Specifies the type of the eigenvalue problem.

949:    Logically Collective

951:    Input Parameters:
952: +  eps  - the linear eigensolver context
953: -  type - a known type of eigenvalue problem

955:    Options Database Keys:
956: +  -eps_hermitian             - Hermitian eigenvalue problem
957: .  -eps_gen_hermitian         - generalized Hermitian eigenvalue problem
958: .  -eps_non_hermitian         - non-Hermitian eigenvalue problem
959: .  -eps_gen_non_hermitian     - generalized non-Hermitian eigenvalue problem
960: .  -eps_pos_gen_non_hermitian - generalized non-Hermitian eigenvalue problem
961:                                 with positive semi-definite $B$
962: .  -eps_gen_indefinite        - generalized Hermitian-indefinite eigenvalue problem
963: .  -eps_bse                   - structured Bethe-Salpeter eigenvalue problem
964: .  -eps_hamiltonian           - structured Hamiltonian eigenvalue problem
965: -  -eps_lrep                  - structured Linear Response eigenvalue problem

967:    Notes:
968:    This function must be used to instruct SLEPc to exploit symmetry or other
969:    kind of structure. If no
970:    problem type is specified, by default a non-Hermitian problem is assumed
971:    (either standard or generalized). If the user knows that the problem is
972:    Hermitian (i.e., $A=A^*$) or generalized Hermitian (i.e., $A=A^*$, $B=B^*$,
973:    and $B$ positive definite) then it is recommended to set the problem type so
974:    that the eigensolver can exploit these properties.

976:    If the user does not call this function, the solver will use a reasonable
977:    guess.

979:    For structured problem types such as `EPS_BSE`, the matrices passed in via
980:    `EPSSetOperators()` must have been created with the corresponding helper
981:    function, i.e., `MatCreateBSE()`.

983:    Level: intermediate

985: .seealso: [](ch:eps), `EPSSetOperators()`, `EPSSetType()`, `EPSGetProblemType()`, `EPSProblemType`
986: @*/
987: PetscErrorCode EPSSetProblemType(EPS eps,EPSProblemType type)
988: {
989:   PetscFunctionBegin;
992:   if (type == eps->problem_type) PetscFunctionReturn(PETSC_SUCCESS);
993:   switch (type) {
994:     case EPS_HEP:
995:       eps->isgeneralized = PETSC_FALSE;
996:       eps->ishermitian = PETSC_TRUE;
997:       eps->ispositive = PETSC_FALSE;
998:       eps->isstructured = PETSC_FALSE;
999:       break;
1000:     case EPS_NHEP:
1001:       eps->isgeneralized = PETSC_FALSE;
1002:       eps->ishermitian = PETSC_FALSE;
1003:       eps->ispositive = PETSC_FALSE;
1004:       eps->isstructured = PETSC_FALSE;
1005:       break;
1006:     case EPS_GHEP:
1007:       eps->isgeneralized = PETSC_TRUE;
1008:       eps->ishermitian = PETSC_TRUE;
1009:       eps->ispositive = PETSC_TRUE;
1010:       eps->isstructured = PETSC_FALSE;
1011:       break;
1012:     case EPS_GNHEP:
1013:       eps->isgeneralized = PETSC_TRUE;
1014:       eps->ishermitian = PETSC_FALSE;
1015:       eps->ispositive = PETSC_FALSE;
1016:       eps->isstructured = PETSC_FALSE;
1017:       break;
1018:     case EPS_PGNHEP:
1019:       eps->isgeneralized = PETSC_TRUE;
1020:       eps->ishermitian = PETSC_FALSE;
1021:       eps->ispositive = PETSC_TRUE;
1022:       eps->isstructured = PETSC_FALSE;
1023:       break;
1024:     case EPS_GHIEP:
1025:       eps->isgeneralized = PETSC_TRUE;
1026:       eps->ishermitian = PETSC_TRUE;
1027:       eps->ispositive = PETSC_FALSE;
1028:       eps->isstructured = PETSC_FALSE;
1029:       break;
1030:     case EPS_BSE:
1031:       eps->isgeneralized = PETSC_FALSE;
1032:       eps->ishermitian = PETSC_FALSE;
1033:       eps->ispositive = PETSC_FALSE;
1034:       eps->isstructured = PETSC_TRUE;
1035:       break;
1036:     case EPS_HAMILT:
1037:       eps->isgeneralized = PETSC_FALSE;
1038:       eps->ishermitian = PETSC_FALSE;
1039:       eps->ispositive = PETSC_FALSE;
1040:       eps->isstructured = PETSC_TRUE;
1041:       break;
1042:     case EPS_LREP:
1043:       eps->isgeneralized = PETSC_FALSE;
1044:       eps->ishermitian = PETSC_FALSE;
1045:       eps->ispositive = PETSC_FALSE;
1046:       eps->isstructured = PETSC_TRUE;
1047:       break;
1048:     default:
1049:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"Unknown eigenvalue problem type");
1050:   }
1051:   eps->problem_type = type;
1052:   eps->state = EPS_STATE_INITIAL;
1053:   PetscFunctionReturn(PETSC_SUCCESS);
1054: }

1056: /*@
1057:    EPSGetProblemType - Gets the problem type from the `EPS` object.

1059:    Not Collective

1061:    Input Parameter:
1062: .  eps - the linear eigensolver context

1064:    Output Parameter:
1065: .  type - the problem type

1067:    Level: intermediate

1069: .seealso: [](ch:eps), `EPSSetProblemType()`, `EPSProblemType`
1070: @*/
1071: PetscErrorCode EPSGetProblemType(EPS eps,EPSProblemType *type)
1072: {
1073:   PetscFunctionBegin;
1075:   PetscAssertPointer(type,2);
1076:   *type = eps->problem_type;
1077:   PetscFunctionReturn(PETSC_SUCCESS);
1078: }

1080: /*@
1081:    EPSSetExtraction - Specifies the type of extraction technique to be employed
1082:    by the eigensolver.

1084:    Logically Collective

1086:    Input Parameters:
1087: +  eps  - the linear eigensolver context
1088: -  extr - a known type of extraction

1090:    Options Database Keys:
1091: +  -eps_ritz              - Rayleigh-Ritz extraction
1092: .  -eps_harmonic          - harmonic Ritz extraction
1093: .  -eps_harmonic_relative - harmonic Ritz extraction relative to the eigenvalue
1094: .  -eps_harmonic_right    - harmonic Ritz extraction for rightmost eigenvalues
1095: .  -eps_harmonic_largest  - harmonic Ritz extraction for largest magnitude (without target)
1096: .  -eps_refined           - refined Ritz extraction
1097: -  -eps_refined_harmonic  - refined harmonic Ritz extraction

1099:    Notes:
1100:    Not all eigensolvers support all types of extraction.

1102:    By default, a standard Rayleigh-Ritz extraction is used. Other extractions
1103:    may be useful when computing interior eigenvalues.

1105:    Harmonic-type extractions are used in combination with a target, see `EPSSetTarget()`.

1107:    Level: advanced

1109: .seealso: [](ch:eps), [](#sec:harmonic), `EPSSetTarget()`, `EPSGetExtraction()`, `EPSExtraction`
1110: @*/
1111: PetscErrorCode EPSSetExtraction(EPS eps,EPSExtraction extr)
1112: {
1113:   PetscFunctionBegin;
1116:   if (eps->extraction != extr) {
1117:     eps->state      = EPS_STATE_INITIAL;
1118:     eps->extraction = extr;
1119:   }
1120:   PetscFunctionReturn(PETSC_SUCCESS);
1121: }

1123: /*@
1124:    EPSGetExtraction - Gets the extraction type used by the `EPS` object.

1126:    Not Collective

1128:    Input Parameter:
1129: .  eps - the linear eigensolver context

1131:    Output Parameter:
1132: .  extr - name of extraction type

1134:    Level: advanced

1136: .seealso: [](ch:eps), `EPSSetExtraction()`, `EPSExtraction`
1137: @*/
1138: PetscErrorCode EPSGetExtraction(EPS eps,EPSExtraction *extr)
1139: {
1140:   PetscFunctionBegin;
1142:   PetscAssertPointer(extr,2);
1143:   *extr = eps->extraction;
1144:   PetscFunctionReturn(PETSC_SUCCESS);
1145: }

1147: /*@
1148:    EPSSetBalance - Specifies the balancing technique to be employed by the
1149:    eigensolver, and some parameters associated to it.

1151:    Logically Collective

1153:    Input Parameters:
1154: +  eps    - the linear eigensolver context
1155: .  bal    - the balancing method, see `EPSBalance` for possible values
1156: .  its    - number of iterations of the balancing algorithm
1157: -  cutoff - cutoff value

1159:    Options Database Keys:
1160: +  -eps_balance (none|oneside|twoside|user) - the balancing method
1161: .  -eps_balance_its its                     - number of iterations
1162: -  -eps_balance_cutoff cutoff               - cutoff value

1164:    Notes:
1165:    When balancing is enabled, the solver works implicitly with matrix $DAD^{-1}$,
1166:    where $D$ is an appropriate diagonal matrix. This improves the accuracy of
1167:    the computed results in some cases, see [](sec:balancing).

1169:    Balancing makes sense only for non-Hermitian problems when the required
1170:    precision is high (i.e., a small tolerance such as `1e-14`).

1172:    By default, balancing is disabled. The two-sided method is much more
1173:    effective than the one-sided counterpart, but it requires the system
1174:    matrices to have the `MatMultTranspose()` operation defined. The methods
1175:    are described in {cite:p}`Che00`.

1177:    The parameter `its` is the number of iterations performed by the method. The
1178:    `cutoff` value is used only in the two-side variant. Use `PETSC_DETERMINE` to assign
1179:    a reasonably good value, or `PETSC_CURRENT` to leave the value unchanged.

1181:    User-defined balancing is allowed provided that the corresponding matrix
1182:    is set via `STSetBalanceMatrix()`.

1184:    Level: intermediate

1186: .seealso: [](ch:eps), [](sec:balancing), `EPSGetBalance()`, `EPSBalance`, `STSetBalanceMatrix()`
1187: @*/
1188: PetscErrorCode EPSSetBalance(EPS eps,EPSBalance bal,PetscInt its,PetscReal cutoff)
1189: {
1190:   PetscFunctionBegin;
1195:   switch (bal) {
1196:     case EPS_BALANCE_NONE:
1197:     case EPS_BALANCE_ONESIDE:
1198:     case EPS_BALANCE_TWOSIDE:
1199:     case EPS_BALANCE_USER:
1200:       if (eps->balance != bal) {
1201:         eps->state = EPS_STATE_INITIAL;
1202:         eps->balance = bal;
1203:       }
1204:       break;
1205:     default:
1206:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid value of argument 'bal'");
1207:   }
1208:   if (its==PETSC_DETERMINE) eps->balance_its = 5;
1209:   else if (its!=PETSC_CURRENT) {
1210:     PetscCheck(its>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be > 0");
1211:     eps->balance_its = its;
1212:   }
1213:   if (cutoff==(PetscReal)PETSC_DETERMINE) eps->balance_cutoff = 1e-8;
1214:   else if (cutoff!=(PetscReal)PETSC_CURRENT) {
1215:     PetscCheck(cutoff>0.0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of cutoff. Must be > 0");
1216:     eps->balance_cutoff = cutoff;
1217:   }
1218:   PetscFunctionReturn(PETSC_SUCCESS);
1219: }

1221: /*@
1222:    EPSGetBalance - Gets the balancing type used by the `EPS` object, and the
1223:    associated parameters.

1225:    Not Collective

1227:    Input Parameter:
1228: .  eps - the linear eigensolver context

1230:    Output Parameters:
1231: +  bal    - the balancing method
1232: .  its    - number of iterations of the balancing algorithm
1233: -  cutoff - cutoff value

1235:    Level: intermediate

1237:    Note:
1238:    The user can specify `NULL` for any parameter that is not needed.

1240: .seealso: [](ch:eps), `EPSSetBalance()`, `EPSBalance`
1241: @*/
1242: PetscErrorCode EPSGetBalance(EPS eps,EPSBalance *bal,PetscInt *its,PetscReal *cutoff)
1243: {
1244:   PetscFunctionBegin;
1246:   if (bal)    *bal = eps->balance;
1247:   if (its)    *its = eps->balance_its;
1248:   if (cutoff) *cutoff = eps->balance_cutoff;
1249:   PetscFunctionReturn(PETSC_SUCCESS);
1250: }

1252: /*@
1253:    EPSSetTwoSided - Sets the solver to use a two-sided variant so that left
1254:    eigenvectors are also computed.

1256:    Logically Collective

1258:    Input Parameters:
1259: +  eps      - the linear eigensolver context
1260: -  twosided - whether the two-sided variant is to be used or not

1262:    Options Database Key:
1263: .  -eps_two_sided (true|false) - toggles the twosided flag

1265:    Notes:
1266:    If the user sets `twosided`=`PETSC_TRUE` then the solver uses a variant of
1267:    the algorithm that computes both right and left eigenvectors. This is
1268:    usually much more costly. This option is not available in all solvers,
1269:    see table [](#tab:support).

1271:    When using two-sided solvers, the problem matrices must have both the
1272:    `MATOP_MULT` and `MATOP_MULT_TRANSPOSE` operations defined.

1274:    Level: advanced

1276: .seealso: [](ch:eps), `EPSGetTwoSided()`, `EPSGetLeftEigenvector()`
1277: @*/
1278: PetscErrorCode EPSSetTwoSided(EPS eps,PetscBool twosided)
1279: {
1280:   PetscFunctionBegin;
1283:   if (twosided!=eps->twosided) {
1284:     eps->twosided = twosided;
1285:     eps->state    = EPS_STATE_INITIAL;
1286:   }
1287:   PetscFunctionReturn(PETSC_SUCCESS);
1288: }

1290: /*@
1291:    EPSGetTwoSided - Returns the flag indicating whether a two-sided variant
1292:    of the algorithm is being used or not.

1294:    Not Collective

1296:    Input Parameter:
1297: .  eps - the linear eigensolver context

1299:    Output Parameter:
1300: .  twosided - the returned flag

1302:    Level: advanced

1304: .seealso: [](ch:eps), `EPSSetTwoSided()`
1305: @*/
1306: PetscErrorCode EPSGetTwoSided(EPS eps,PetscBool *twosided)
1307: {
1308:   PetscFunctionBegin;
1310:   PetscAssertPointer(twosided,2);
1311:   *twosided = eps->twosided;
1312:   PetscFunctionReturn(PETSC_SUCCESS);
1313: }

1315: /*@
1316:    EPSSetTrueResidual - Specifies if the solver must compute the true residual
1317:    explicitly or not.

1319:    Logically Collective

1321:    Input Parameters:
1322: +  eps     - the linear eigensolver context
1323: -  trueres - whether true residuals are required or not

1325:    Options Database Key:
1326: .  -eps_true_residual (true|false) - toggles the true residual

1328:    Notes:
1329:    If the user sets `trueres`=`PETSC_TRUE` then the solver explicitly computes
1330:    the true residual for each eigenpair approximation, and uses it for
1331:    convergence testing. Computing the residual is usually an expensive
1332:    operation. Some solvers (e.g., Krylov solvers) can avoid this computation
1333:    by using a cheap estimate of the residual norm, but this may sometimes
1334:    give inaccurate results (especially if a spectral transform is being
1335:    used). On the contrary, preconditioned eigensolvers (e.g., Davidson solvers)
1336:    do rely on computing the true residual, so this option is irrelevant for them.

1338:    Level: advanced

1340: .seealso: [](ch:eps), `EPSGetTrueResidual()`
1341: @*/
1342: PetscErrorCode EPSSetTrueResidual(EPS eps,PetscBool trueres)
1343: {
1344:   PetscFunctionBegin;
1347:   eps->trueres = trueres;
1348:   PetscFunctionReturn(PETSC_SUCCESS);
1349: }

1351: /*@
1352:    EPSGetTrueResidual - Returns the flag indicating whether true
1353:    residuals must be computed explicitly or not.

1355:    Not Collective

1357:    Input Parameter:
1358: .  eps - the linear eigensolver context

1360:    Output Parameter:
1361: .  trueres - the returned flag

1363:    Level: advanced

1365: .seealso: [](ch:eps), `EPSSetTrueResidual()`
1366: @*/
1367: PetscErrorCode EPSGetTrueResidual(EPS eps,PetscBool *trueres)
1368: {
1369:   PetscFunctionBegin;
1371:   PetscAssertPointer(trueres,2);
1372:   *trueres = eps->trueres;
1373:   PetscFunctionReturn(PETSC_SUCCESS);
1374: }

1376: /*@
1377:    EPSSetTrackAll - Specifies if the solver must compute the residual norm of all
1378:    approximate eigenpairs or not.

1380:    Logically Collective

1382:    Input Parameters:
1383: +  eps      - the linear eigensolver context
1384: -  trackall - whether to compute all residuals or not

1386:    Notes:
1387:    If the user sets `trackall`=`PETSC_TRUE` then the solver computes (or estimates)
1388:    the residual norm for each eigenpair approximation. Computing the residual is
1389:    usually an expensive operation and solvers commonly compute only the residual
1390:    associated to the first unconverged eigenpair.

1392:    The option `-eps_monitor_all` automatically activates this option.

1394:    Level: developer

1396: .seealso: [](ch:eps), `EPSGetTrackAll()`
1397: @*/
1398: PetscErrorCode EPSSetTrackAll(EPS eps,PetscBool trackall)
1399: {
1400:   PetscFunctionBegin;
1403:   eps->trackall = trackall;
1404:   PetscFunctionReturn(PETSC_SUCCESS);
1405: }

1407: /*@
1408:    EPSGetTrackAll - Returns the flag indicating whether all residual norms must
1409:    be computed or not.

1411:    Not Collective

1413:    Input Parameter:
1414: .  eps - the linear eigensolver context

1416:    Output Parameter:
1417: .  trackall - the returned flag

1419:    Level: developer

1421: .seealso: [](ch:eps), `EPSSetTrackAll()`
1422: @*/
1423: PetscErrorCode EPSGetTrackAll(EPS eps,PetscBool *trackall)
1424: {
1425:   PetscFunctionBegin;
1427:   PetscAssertPointer(trackall,2);
1428:   *trackall = eps->trackall;
1429:   PetscFunctionReturn(PETSC_SUCCESS);
1430: }

1432: /*@
1433:    EPSSetPurify - Disable eigenvector purification (which is enabled by default).

1435:    Logically Collective

1437:    Input Parameters:
1438: +  eps    - the linear eigensolver context
1439: -  purify - whether purification is done or not, use `PETSC_FALSE` to disable it

1441:    Options Database Key:
1442: .  -eps_purify (true|false) - toggles the purification flag

1444:    Notes:
1445:    By default, eigenvectors of generalized symmetric eigenproblems are purified
1446:    in order to purge directions in the nullspace of matrix $B$. If the user knows
1447:    that $B$ is non-singular, then purification can be safely deactivated and some
1448:    computational cost is avoided (this is particularly important in interval computations).

1450:    More details are given in section [](#sec:purif).

1452:    Level: intermediate

1454: .seealso: [](ch:eps), [](#sec:purif), `EPSGetPurify()`, `EPSSetInterval()`
1455: @*/
1456: PetscErrorCode EPSSetPurify(EPS eps,PetscBool purify)
1457: {
1458:   PetscFunctionBegin;
1461:   if (purify!=eps->purify) {
1462:     eps->purify = purify;
1463:     eps->state  = EPS_STATE_INITIAL;
1464:   }
1465:   PetscFunctionReturn(PETSC_SUCCESS);
1466: }

1468: /*@
1469:    EPSGetPurify - Returns the flag indicating whether purification is activated
1470:    or not.

1472:    Not Collective

1474:    Input Parameter:
1475: .  eps - the linear eigensolver context

1477:    Output Parameter:
1478: .  purify - the returned flag

1480:    Level: intermediate

1482: .seealso: [](ch:eps), `EPSSetPurify()`
1483: @*/
1484: PetscErrorCode EPSGetPurify(EPS eps,PetscBool *purify)
1485: {
1486:   PetscFunctionBegin;
1488:   PetscAssertPointer(purify,2);
1489:   *purify = eps->purify;
1490:   PetscFunctionReturn(PETSC_SUCCESS);
1491: }

1493: /*@
1494:    EPSSetOptionsPrefix - Sets the prefix used for searching for all
1495:    `EPS` options in the database.

1497:    Logically Collective

1499:    Input Parameters:
1500: +  eps    - the linear eigensolver context
1501: -  prefix - the prefix string to prepend to all `EPS` option requests

1503:    Notes:
1504:    A hyphen (-) must NOT be given at the beginning of the prefix name.
1505:    The first character of all runtime options is AUTOMATICALLY the
1506:    hyphen.

1508:    For example, to distinguish between the runtime options for two
1509:    different `EPS` contexts, one could call
1510: .vb
1511:    EPSSetOptionsPrefix(eps1,"eig1_")
1512:    EPSSetOptionsPrefix(eps2,"eig2_")
1513: .ve

1515:    Level: advanced

1517: .seealso: [](ch:eps), `EPSAppendOptionsPrefix()`, `EPSGetOptionsPrefix()`
1518: @*/
1519: PetscErrorCode EPSSetOptionsPrefix(EPS eps,const char prefix[])
1520: {
1521:   PetscFunctionBegin;
1523:   if (!eps->st) PetscCall(EPSGetST(eps,&eps->st));
1524:   PetscCall(STSetOptionsPrefix(eps->st,prefix));
1525:   if (!eps->V) PetscCall(EPSGetBV(eps,&eps->V));
1526:   PetscCall(BVSetOptionsPrefix(eps->V,prefix));
1527:   if (!eps->ds) PetscCall(EPSGetDS(eps,&eps->ds));
1528:   PetscCall(DSSetOptionsPrefix(eps->ds,prefix));
1529:   if (!eps->rg) PetscCall(EPSGetRG(eps,&eps->rg));
1530:   PetscCall(RGSetOptionsPrefix(eps->rg,prefix));
1531:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)eps,prefix));
1532:   PetscFunctionReturn(PETSC_SUCCESS);
1533: }

1535: /*@
1536:    EPSAppendOptionsPrefix - Appends to the prefix used for searching for all
1537:    `EPS` options in the database.

1539:    Logically Collective

1541:    Input Parameters:
1542: +  eps    - the linear eigensolver context
1543: -  prefix - the prefix string to prepend to all `EPS` option requests

1545:    Notes:
1546:    A hyphen (-) must NOT be given at the beginning of the prefix name.
1547:    The first character of all runtime options is AUTOMATICALLY the hyphen.

1549:    Level: advanced

1551: .seealso: [](ch:eps), `EPSSetOptionsPrefix()`, `EPSGetOptionsPrefix()`
1552: @*/
1553: PetscErrorCode EPSAppendOptionsPrefix(EPS eps,const char prefix[])
1554: {
1555:   PetscFunctionBegin;
1557:   if (!eps->st) PetscCall(EPSGetST(eps,&eps->st));
1558:   PetscCall(STAppendOptionsPrefix(eps->st,prefix));
1559:   if (!eps->V) PetscCall(EPSGetBV(eps,&eps->V));
1560:   PetscCall(BVAppendOptionsPrefix(eps->V,prefix));
1561:   if (!eps->ds) PetscCall(EPSGetDS(eps,&eps->ds));
1562:   PetscCall(DSAppendOptionsPrefix(eps->ds,prefix));
1563:   if (!eps->rg) PetscCall(EPSGetRG(eps,&eps->rg));
1564:   PetscCall(RGAppendOptionsPrefix(eps->rg,prefix));
1565:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)eps,prefix));
1566:   PetscFunctionReturn(PETSC_SUCCESS);
1567: }

1569: /*@
1570:    EPSGetOptionsPrefix - Gets the prefix used for searching for all
1571:    `EPS` options in the database.

1573:    Not Collective

1575:    Input Parameter:
1576: .  eps - the linear eigensolver context

1578:    Output Parameter:
1579: .  prefix - pointer to the prefix string used is returned

1581:    Level: advanced

1583: .seealso: [](ch:eps), `EPSSetOptionsPrefix()`, `EPSAppendOptionsPrefix()`
1584: @*/
1585: PetscErrorCode EPSGetOptionsPrefix(EPS eps,const char *prefix[])
1586: {
1587:   PetscFunctionBegin;
1589:   PetscAssertPointer(prefix,2);
1590:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)eps,prefix));
1591:   PetscFunctionReturn(PETSC_SUCCESS);
1592: }