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[],void *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(PetscOptionsBoolGroupEnd("-eps_hamiltonian","Structured Hamiltonian eigenvalue problem","EPSSetProblemType",&flg));
116:     if (flg) PetscCall(EPSSetProblemType(eps,EPS_HAMILT));

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

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

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

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

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

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

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

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

199:     PetscCall(PetscOptionsScalar("-eps_target","Value of the target","EPSSetTarget",eps->target,&s,&flg));
200:     if (flg) {
201:       if (eps->which!=EPS_TARGET_REAL && eps->which!=EPS_TARGET_IMAGINARY) PetscCall(EPSSetWhichEigenpairs(eps,EPS_TARGET_MAGNITUDE));
202:       PetscCall(EPSSetTarget(eps,s));
203:     }

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

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

219:     /* -----------------------------------------------------------------------*/
220:     /*
221:       Cancels all monitors hardwired into code before call to EPSSetFromOptions()
222:     */
223:     PetscCall(PetscOptionsBool("-eps_monitor_cancel","Remove any hardwired monitor routines","EPSMonitorCancel",PETSC_FALSE,&flg,&set));
224:     if (set && flg) PetscCall(EPSMonitorCancel(eps));
225:     PetscCall(EPSMonitorSetFromOptions(eps,"-eps_monitor","first_approximation",NULL,PETSC_FALSE));
226:     PetscCall(EPSMonitorSetFromOptions(eps,"-eps_monitor_all","all_approximations",NULL,PETSC_TRUE));
227:     PetscCall(EPSMonitorSetFromOptions(eps,"-eps_monitor_conv","convergence_history",NULL,PETSC_FALSE));

229:     /* -----------------------------------------------------------------------*/
230:     PetscCall(PetscOptionsName("-eps_view","Print detailed information on solver used","EPSView",&set));
231:     PetscCall(PetscOptionsName("-eps_view_vectors","View computed eigenvectors","EPSVectorsView",&set));
232:     PetscCall(PetscOptionsName("-eps_view_values","View computed eigenvalues","EPSValuesView",&set));
233:     PetscCall(PetscOptionsName("-eps_converged_reason","Print reason for convergence, and number of iterations","EPSConvergedReasonView",&set));
234:     PetscCall(PetscOptionsName("-eps_error_absolute","Print absolute errors of each eigenpair","EPSErrorView",&set));
235:     PetscCall(PetscOptionsName("-eps_error_relative","Print relative errors of each eigenpair","EPSErrorView",&set));
236:     PetscCall(PetscOptionsName("-eps_error_backward","Print backward errors of each eigenpair","EPSErrorView",&set));

238:     PetscTryTypeMethod(eps,setfromoptions,PetscOptionsObject);
239:     PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)eps,PetscOptionsObject));
240:   PetscOptionsEnd();

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

257: /*@
258:    EPSGetTolerances - Gets the tolerance and maximum iteration count used
259:    by the `EPS` convergence tests.

261:    Not Collective

263:    Input Parameter:
264: .  eps - the linear eigensolver context

266:    Output Parameters:
267: +  tol - the convergence tolerance
268: -  maxits - maximum number of iterations

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

273:    Level: intermediate

275: .seealso: [](ch:eps), `EPSSetTolerances()`
276: @*/
277: PetscErrorCode EPSGetTolerances(EPS eps,PetscReal *tol,PetscInt *maxits)
278: {
279:   PetscFunctionBegin;
281:   if (tol)    *tol    = eps->tol;
282:   if (maxits) *maxits = eps->max_it;
283:   PetscFunctionReturn(PETSC_SUCCESS);
284: }

286: /*@
287:    EPSSetTolerances - Sets the tolerance and maximum iteration count used
288:    by the `EPS` convergence tests.

290:    Logically Collective

292:    Input Parameters:
293: +  eps    - the linear eigensolver context
294: .  tol    - the convergence tolerance
295: -  maxits - maximum number of iterations to use

297:    Options Database Keys:
298: +  -eps_tol \<tol\>       - sets the convergence tolerance
299: -  -eps_max_it \<maxits\> - sets the maximum number of iterations allowed

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

307:    Level: intermediate

309: .seealso: [](ch:eps), `EPSGetTolerances()`
310: @*/
311: PetscErrorCode EPSSetTolerances(EPS eps,PetscReal tol,PetscInt maxits)
312: {
313:   PetscFunctionBegin;
317:   if (tol == (PetscReal)PETSC_DETERMINE) {
318:     eps->tol   = PETSC_DETERMINE;
319:     eps->state = EPS_STATE_INITIAL;
320:   } else if (tol != (PetscReal)PETSC_CURRENT) {
321:     PetscCheck(tol>0.0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
322:     eps->tol = tol;
323:   }
324:   if (maxits == PETSC_DETERMINE) {
325:     eps->max_it = PETSC_DETERMINE;
326:     eps->state  = EPS_STATE_INITIAL;
327:   } else if (maxits == PETSC_UNLIMITED) {
328:     eps->max_it = PETSC_INT_MAX;
329:   } else if (maxits != PETSC_CURRENT) {
330:     PetscCheck(maxits>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
331:     eps->max_it = maxits;
332:   }
333:   PetscFunctionReturn(PETSC_SUCCESS);
334: }

336: /*@
337:    EPSGetDimensions - Gets the number of eigenvalues to compute
338:    and the dimension of the subspace.

340:    Not Collective

342:    Input Parameter:
343: .  eps - the linear eigensolver context

345:    Output Parameters:
346: +  nev - number of eigenvalues to compute
347: .  ncv - the maximum dimension of the subspace to be used by the solver
348: -  mpd - the maximum dimension allowed for the projected problem

350:    Level: intermediate

352: .seealso: [](ch:eps), `EPSSetDimensions()`
353: @*/
354: PetscErrorCode EPSGetDimensions(EPS eps,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
355: {
356:   PetscFunctionBegin;
358:   if (nev) *nev = eps->nev? eps->nev: 1;
359:   if (ncv) *ncv = eps->ncv;
360:   if (mpd) *mpd = eps->mpd;
361:   PetscFunctionReturn(PETSC_SUCCESS);
362: }

364: /*@
365:    EPSSetDimensions - Sets the number of eigenvalues to compute
366:    and the dimension of the subspace.

368:    Logically Collective

370:    Input Parameters:
371: +  eps - the linear eigensolver context
372: .  nev - number of eigenvalues to compute
373: .  ncv - the maximum dimension of the subspace to be used by the solver
374: -  mpd - the maximum dimension allowed for the projected problem

376:    Options Database Keys:
377: +  -eps_nev \<nev\> - sets the number of eigenvalues
378: .  -eps_ncv \<ncv\> - sets the dimension of the subspace
379: -  -eps_mpd \<mpd\> - sets the maximum projected dimension

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

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

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

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

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

400:    Level: intermediate

402: .seealso: [](ch:eps), `EPSGetDimensions()`, `EPSSetInterval()`, `EPSKrylovSchurSetDimensions()`
403: @*/
404: PetscErrorCode EPSSetDimensions(EPS eps,PetscInt nev,PetscInt ncv,PetscInt mpd)
405: {
406:   PetscFunctionBegin;
411:   if (nev != PETSC_CURRENT) {
412:     PetscCheck(nev>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
413:     eps->nev = nev;
414:   }
415:   if (ncv == PETSC_DETERMINE) {
416:     eps->ncv = PETSC_DETERMINE;
417:   } else if (ncv != PETSC_CURRENT) {
418:     PetscCheck(ncv>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
419:     eps->ncv = ncv;
420:   }
421:   if (mpd == PETSC_DETERMINE) {
422:     eps->mpd = PETSC_DETERMINE;
423:   } else if (mpd != PETSC_CURRENT) {
424:     PetscCheck(mpd>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
425:     eps->mpd = mpd;
426:   }
427:   eps->state = EPS_STATE_INITIAL;
428:   PetscFunctionReturn(PETSC_SUCCESS);
429: }

431: /*@
432:    EPSSetWhichEigenpairs - Specifies which portion of the spectrum is
433:    to be sought.

435:    Logically Collective

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

441:    Options Database Keys:
442: +  -eps_largest_magnitude  - sets largest eigenvalues in magnitude
443: .  -eps_smallest_magnitude - sets smallest eigenvalues in magnitude
444: .  -eps_largest_real       - sets largest real parts
445: .  -eps_smallest_real      - sets smallest real parts
446: .  -eps_largest_imaginary  - sets largest imaginary parts
447: .  -eps_smallest_imaginary - sets smallest imaginary parts
448: .  -eps_target_magnitude   - sets eigenvalues closest to target
449: .  -eps_target_real        - sets real parts closest to target
450: .  -eps_target_imaginary   - sets imaginary parts closest to target
451: -  -eps_all                - sets all eigenvalues in an interval or region

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

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

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

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

469:    Level: intermediate

471: .seealso: [](ch:eps), `EPSGetWhichEigenpairs()`, `EPSSetTarget()`, `EPSSetInterval()`, `EPSSetDimensions()`, `EPSSetEigenvalueComparison()`, `EPSWhich`
472: @*/
473: PetscErrorCode EPSSetWhichEigenpairs(EPS eps,EPSWhich which)
474: {
475:   PetscFunctionBegin;
478:   switch (which) {
479:     case EPS_LARGEST_MAGNITUDE:
480:     case EPS_SMALLEST_MAGNITUDE:
481:     case EPS_LARGEST_REAL:
482:     case EPS_SMALLEST_REAL:
483:     case EPS_LARGEST_IMAGINARY:
484:     case EPS_SMALLEST_IMAGINARY:
485:     case EPS_TARGET_MAGNITUDE:
486:     case EPS_TARGET_REAL:
487: #if defined(PETSC_USE_COMPLEX)
488:     case EPS_TARGET_IMAGINARY:
489: #endif
490:     case EPS_ALL:
491:     case EPS_WHICH_USER:
492:       if (eps->which != which) {
493:         eps->state = EPS_STATE_INITIAL;
494:         eps->which = which;
495:       }
496:       break;
497: #if !defined(PETSC_USE_COMPLEX)
498:     case EPS_TARGET_IMAGINARY:
499:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"EPS_TARGET_IMAGINARY can be used only with complex scalars");
500: #endif
501:     default:
502:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'which' value");
503:   }
504:   PetscFunctionReturn(PETSC_SUCCESS);
505: }

507: /*@
508:    EPSGetWhichEigenpairs - Returns which portion of the spectrum is to be
509:    sought.

511:    Not Collective

513:    Input Parameter:
514: .  eps - the linear eigensolver context

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

519:    Level: intermediate

521: .seealso: [](ch:eps), `EPSSetWhichEigenpairs()`, `EPSWhich`
522: @*/
523: PetscErrorCode EPSGetWhichEigenpairs(EPS eps,EPSWhich *which)
524: {
525:   PetscFunctionBegin;
527:   PetscAssertPointer(which,2);
528:   *which = eps->which;
529:   PetscFunctionReturn(PETSC_SUCCESS);
530: }

532: /*@
533:    EPSSetThreshold - Sets the threshold used in the threshold stopping test.

535:    Logically Collective

537:    Input Parameters:
538: +  eps   - the linear eigensolver context
539: .  thres - the threshold value
540: -  rel   - whether the threshold is relative or not

542:    Options Database Keys:
543: +  -eps_threshold_absolute \<thres\> - sets an absolute threshold
544: -  -eps_threshold_relative \<thres\> - sets a relative threshold

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

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

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

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

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

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

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

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

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

593:    Level: advanced

595: .seealso: [](ch:eps), `EPSGetThreshold()`, `EPSSetStoppingTest()`, `EPSSetDimensions()`, `EPSSetWhichEigenpairs()`, `EPSSetProblemType()`
596: @*/
597: PetscErrorCode EPSSetThreshold(EPS eps,PetscReal thres,PetscBool rel)
598: {
599:   PetscFunctionBegin;
603:   if (eps->thres != thres || eps->threlative != rel) {
604:     eps->thres = thres;
605:     eps->threlative = rel;
606:     eps->state = EPS_STATE_INITIAL;
607:     PetscCall(EPSSetStoppingTest(eps,EPS_STOP_THRESHOLD));
608:   }
609:   PetscFunctionReturn(PETSC_SUCCESS);
610: }

612: /*@
613:    EPSGetThreshold - Gets the threshold used by the threshold stopping test.

615:    Not Collective

617:    Input Parameter:
618: .  eps - the linear eigensolver context

620:    Output Parameters:
621: +  thres - the threshold
622: -  rel   - whether the threshold is relative or not

624:    Level: advanced

626: .seealso: [](ch:eps), `EPSSetThreshold()`
627: @*/
628: PetscErrorCode EPSGetThreshold(EPS eps,PetscReal *thres,PetscBool *rel)
629: {
630:   PetscFunctionBegin;
632:   if (thres) *thres = eps->thres;
633:   if (rel)   *rel   = eps->threlative;
634:   PetscFunctionReturn(PETSC_SUCCESS);
635: }

637: /*@C
638:    EPSSetEigenvalueComparison - Specifies the eigenvalue comparison function
639:    when `EPSSetWhichEigenpairs()` is set to `EPS_WHICH_USER`.

641:    Logically Collective

643:    Input Parameters:
644: +  eps  - the linear eigensolver context
645: .  func - the comparison function, see `SlepcEigenvalueComparisonFn` for the calling sequence
646: -  ctx  - a context pointer (the last parameter to the comparison function)

648:    Level: advanced

650: .seealso: [](ch:eps), `EPSSetWhichEigenpairs()`, `EPSWhich`
651: @*/
652: PetscErrorCode EPSSetEigenvalueComparison(EPS eps,SlepcEigenvalueComparisonFn *func,void *ctx)
653: {
654:   PetscFunctionBegin;
656:   eps->sc->comparison    = func;
657:   eps->sc->comparisonctx = ctx;
658:   eps->which             = EPS_WHICH_USER;
659:   PetscFunctionReturn(PETSC_SUCCESS);
660: }

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

667:    Logically Collective

669:    Input Parameters:
670: +  eps  - the linear eigensolver context
671: .  func - the arbitrary selection function, see `SlepcArbitrarySelectionFn` for a calling sequence
672: -  ctx  - a context pointer (the last parameter to the arbitrary selection function)

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

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

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

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

694:    Level: advanced

696: .seealso: [](ch:eps), `EPSSetWhichEigenpairs()`
697: @*/
698: PetscErrorCode EPSSetArbitrarySelection(EPS eps,SlepcArbitrarySelectionFn *func,void *ctx)
699: {
700:   PetscFunctionBegin;
702:   eps->arbitrary    = func;
703:   eps->arbitraryctx = ctx;
704:   eps->state        = EPS_STATE_INITIAL;
705:   PetscFunctionReturn(PETSC_SUCCESS);
706: }

708: /*@C
709:    EPSSetConvergenceTestFunction - Sets a function to compute the error estimate
710:    used in the convergence test.

712:    Logically Collective

714:    Input Parameters:
715: +  eps     - the linear eigensolver context
716: .  func    - convergence test function, see `EPSConvergenceTestFn` for the calling sequence
717: .  ctx     - context for private data for the convergence routine (may be `NULL`)
718: -  destroy - a routine for destroying the context (may be `NULL`), see `PetscCtxDestroyFn`
719:              for the calling sequence

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

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

728:    Level: advanced

730: .seealso: [](ch:eps), `EPSSetConvergenceTest()`, `EPSSetTolerances()`
731: @*/
732: PetscErrorCode EPSSetConvergenceTestFunction(EPS eps,EPSConvergenceTestFn *func,void *ctx,PetscCtxDestroyFn *destroy)
733: {
734:   PetscFunctionBegin;
736:   if (eps->convergeddestroy) PetscCall((*eps->convergeddestroy)(&eps->convergedctx));
737:   eps->convergeduser    = func;
738:   eps->convergeddestroy = destroy;
739:   eps->convergedctx     = ctx;
740:   if (func == EPSConvergedRelative) eps->conv = EPS_CONV_REL;
741:   else if (func == EPSConvergedNorm) eps->conv = EPS_CONV_NORM;
742:   else if (func == EPSConvergedAbsolute) eps->conv = EPS_CONV_ABS;
743:   else {
744:     eps->conv      = EPS_CONV_USER;
745:     eps->converged = eps->convergeduser;
746:   }
747:   PetscFunctionReturn(PETSC_SUCCESS);
748: }

750: /*@
751:    EPSSetConvergenceTest - Specifies how to compute the error estimate
752:    used in the convergence test.

754:    Logically Collective

756:    Input Parameters:
757: +  eps  - the linear eigensolver context
758: -  conv - the type of convergence test, see `EPSConv` for possible values

760:    Options Database Keys:
761: +  -eps_conv_abs  - sets the absolute convergence test
762: .  -eps_conv_rel  - sets the convergence test relative to the eigenvalue
763: .  -eps_conv_norm - sets the convergence test relative to the matrix norms
764: -  -eps_conv_user - selects the user-defined convergence test

766:    Level: intermediate

768: .seealso: [](ch:eps), `EPSGetConvergenceTest()`, `EPSSetConvergenceTestFunction()`, `EPSSetStoppingTest()`, `EPSConv`
769: @*/
770: PetscErrorCode EPSSetConvergenceTest(EPS eps,EPSConv conv)
771: {
772:   PetscFunctionBegin;
775:   switch (conv) {
776:     case EPS_CONV_ABS:  eps->converged = EPSConvergedAbsolute; break;
777:     case EPS_CONV_REL:  eps->converged = EPSConvergedRelative; break;
778:     case EPS_CONV_NORM: eps->converged = EPSConvergedNorm; break;
779:     case EPS_CONV_USER:
780:       PetscCheck(eps->convergeduser,PetscObjectComm((PetscObject)eps),PETSC_ERR_ORDER,"Must call EPSSetConvergenceTestFunction() first");
781:       eps->converged = eps->convergeduser;
782:       break;
783:     default:
784:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'conv' value");
785:   }
786:   eps->conv = conv;
787:   PetscFunctionReturn(PETSC_SUCCESS);
788: }

790: /*@
791:    EPSGetConvergenceTest - Gets the method used to compute the error estimate
792:    used in the convergence test.

794:    Not Collective

796:    Input Parameter:
797: .  eps   - the linear eigensolver context

799:    Output Parameter:
800: .  conv  - the type of convergence test

802:    Level: intermediate

804: .seealso: [](ch:eps), `EPSSetConvergenceTest()`, `EPSConv`
805: @*/
806: PetscErrorCode EPSGetConvergenceTest(EPS eps,EPSConv *conv)
807: {
808:   PetscFunctionBegin;
810:   PetscAssertPointer(conv,2);
811:   *conv = eps->conv;
812:   PetscFunctionReturn(PETSC_SUCCESS);
813: }

815: /*@C
816:    EPSSetStoppingTestFunction - Sets a function to decide when to stop the outer
817:    iteration of the eigensolver.

819:    Logically Collective

821:    Input Parameters:
822: +  eps     - the linear eigensolver context
823: .  func    - stopping test function, see `EPSStoppingTestFn` for the calling sequence
824: .  ctx     - context for private data for the stopping routine (may be `NULL`)
825: -  destroy - a routine for destroying the context (may be `NULL`), see `PetscCtxDestroyFn`
826:              for the calling sequence

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

834:    Level: advanced

836: .seealso: [](ch:eps), `EPSSetStoppingTest()`, `EPSStoppingBasic()`
837: @*/
838: PetscErrorCode EPSSetStoppingTestFunction(EPS eps,EPSStoppingTestFn *func,void *ctx,PetscCtxDestroyFn *destroy)
839: {
840:   PetscFunctionBegin;
842:   if (eps->stoppingdestroy) PetscCall((*eps->stoppingdestroy)(&eps->stoppingctx));
843:   eps->stoppinguser    = func;
844:   eps->stoppingdestroy = destroy;
845:   eps->stoppingctx     = ctx;
846:   if (func == EPSStoppingBasic) PetscCall(EPSSetStoppingTest(eps,EPS_STOP_BASIC));
847:   else if (func == EPSStoppingThreshold) PetscCall(EPSSetStoppingTest(eps,EPS_STOP_THRESHOLD));
848:   else {
849:     eps->stop     = EPS_STOP_USER;
850:     eps->stopping = eps->stoppinguser;
851:   }
852:   PetscFunctionReturn(PETSC_SUCCESS);
853: }

855: /*@
856:    EPSSetStoppingTest - Specifies how to decide the termination of the outer
857:    loop of the eigensolver.

859:    Logically Collective

861:    Input Parameters:
862: +  eps  - the linear eigensolver context
863: -  stop - the type of stopping test, see `EPSStop`

865:    Options Database Keys:
866: +  -eps_stop_basic     - sets the default stopping test
867: .  -eps_stop_threshold - sets the threshold stopping test
868: -  -eps_stop_user      - selects the user-defined stopping test

870:    Level: advanced

872: .seealso: [](ch:eps), `EPSGetStoppingTest()`, `EPSSetStoppingTestFunction()`, `EPSSetConvergenceTest()`, `EPSStop`
873: @*/
874: PetscErrorCode EPSSetStoppingTest(EPS eps,EPSStop stop)
875: {
876:   PetscFunctionBegin;
879:   switch (stop) {
880:     case EPS_STOP_BASIC: eps->stopping = EPSStoppingBasic; break;
881:     case EPS_STOP_THRESHOLD: eps->stopping = EPSStoppingThreshold; break;
882:     case EPS_STOP_USER:
883:       PetscCheck(eps->stoppinguser,PetscObjectComm((PetscObject)eps),PETSC_ERR_ORDER,"Must call EPSSetStoppingTestFunction() first");
884:       eps->stopping = eps->stoppinguser;
885:       break;
886:     default:
887:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'stop' value");
888:   }
889:   eps->stop = stop;
890:   PetscFunctionReturn(PETSC_SUCCESS);
891: }

893: /*@
894:    EPSGetStoppingTest - Gets the method used to decide the termination of the outer
895:    loop of the eigensolver.

897:    Not Collective

899:    Input Parameter:
900: .  eps   - the linear eigensolver context

902:    Output Parameter:
903: .  stop  - the type of stopping test

905:    Level: advanced

907: .seealso: [](ch:eps), `EPSSetStoppingTest()`, `EPSStop`
908: @*/
909: PetscErrorCode EPSGetStoppingTest(EPS eps,EPSStop *stop)
910: {
911:   PetscFunctionBegin;
913:   PetscAssertPointer(stop,2);
914:   *stop = eps->stop;
915:   PetscFunctionReturn(PETSC_SUCCESS);
916: }

918: /*@
919:    EPSSetProblemType - Specifies the type of the eigenvalue problem.

921:    Logically Collective

923:    Input Parameters:
924: +  eps  - the linear eigensolver context
925: -  type - a known type of eigenvalue problem

927:    Options Database Keys:
928: +  -eps_hermitian             - Hermitian eigenvalue problem
929: .  -eps_gen_hermitian         - generalized Hermitian eigenvalue problem
930: .  -eps_non_hermitian         - non-Hermitian eigenvalue problem
931: .  -eps_gen_non_hermitian     - generalized non-Hermitian eigenvalue problem
932: .  -eps_pos_gen_non_hermitian - generalized non-Hermitian eigenvalue problem
933:                                 with positive semi-definite $B$
934: .  -eps_gen_indefinite        - generalized Hermitian-indefinite eigenvalue problem
935: .  -eps_bse                   - structured Bethe-Salpeter eigenvalue problem
936: -  -eps_hamiltonian           - structured Hamiltonian eigenvalue problem

938:    Notes:
939:    This function must be used to instruct SLEPc to exploit symmetry or other
940:    kind of structure. If no
941:    problem type is specified, by default a non-Hermitian problem is assumed
942:    (either standard or generalized). If the user knows that the problem is
943:    Hermitian (i.e., $A=A^*$) or generalized Hermitian (i.e., $A=A^*$, $B=B^*$,
944:    and $B$ positive definite) then it is recommended to set the problem type so
945:    that the eigensolver can exploit these properties.

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

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

954:    Level: intermediate

956: .seealso: [](ch:eps), `EPSSetOperators()`, `EPSSetType()`, `EPSGetProblemType()`, `EPSProblemType`
957: @*/
958: PetscErrorCode EPSSetProblemType(EPS eps,EPSProblemType type)
959: {
960:   PetscFunctionBegin;
963:   if (type == eps->problem_type) PetscFunctionReturn(PETSC_SUCCESS);
964:   switch (type) {
965:     case EPS_HEP:
966:       eps->isgeneralized = PETSC_FALSE;
967:       eps->ishermitian = PETSC_TRUE;
968:       eps->ispositive = PETSC_FALSE;
969:       eps->isstructured = PETSC_FALSE;
970:       break;
971:     case EPS_NHEP:
972:       eps->isgeneralized = PETSC_FALSE;
973:       eps->ishermitian = PETSC_FALSE;
974:       eps->ispositive = PETSC_FALSE;
975:       eps->isstructured = PETSC_FALSE;
976:       break;
977:     case EPS_GHEP:
978:       eps->isgeneralized = PETSC_TRUE;
979:       eps->ishermitian = PETSC_TRUE;
980:       eps->ispositive = PETSC_TRUE;
981:       eps->isstructured = PETSC_FALSE;
982:       break;
983:     case EPS_GNHEP:
984:       eps->isgeneralized = PETSC_TRUE;
985:       eps->ishermitian = PETSC_FALSE;
986:       eps->ispositive = PETSC_FALSE;
987:       eps->isstructured = PETSC_FALSE;
988:       break;
989:     case EPS_PGNHEP:
990:       eps->isgeneralized = PETSC_TRUE;
991:       eps->ishermitian = PETSC_FALSE;
992:       eps->ispositive = PETSC_TRUE;
993:       eps->isstructured = PETSC_FALSE;
994:       break;
995:     case EPS_GHIEP:
996:       eps->isgeneralized = PETSC_TRUE;
997:       eps->ishermitian = PETSC_TRUE;
998:       eps->ispositive = PETSC_FALSE;
999:       eps->isstructured = PETSC_FALSE;
1000:       break;
1001:     case EPS_BSE:
1002:       eps->isgeneralized = PETSC_FALSE;
1003:       eps->ishermitian = PETSC_FALSE;
1004:       eps->ispositive = PETSC_FALSE;
1005:       eps->isstructured = PETSC_TRUE;
1006:       break;
1007:     case EPS_HAMILT:
1008:       eps->isgeneralized = PETSC_FALSE;
1009:       eps->ishermitian = PETSC_FALSE;
1010:       eps->ispositive = PETSC_FALSE;
1011:       eps->isstructured = PETSC_TRUE;
1012:       break;
1013:     default:
1014:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"Unknown eigenvalue problem type");
1015:   }
1016:   eps->problem_type = type;
1017:   eps->state = EPS_STATE_INITIAL;
1018:   PetscFunctionReturn(PETSC_SUCCESS);
1019: }

1021: /*@
1022:    EPSGetProblemType - Gets the problem type from the `EPS` object.

1024:    Not Collective

1026:    Input Parameter:
1027: .  eps - the linear eigensolver context

1029:    Output Parameter:
1030: .  type - the problem type

1032:    Level: intermediate

1034: .seealso: [](ch:eps), `EPSSetProblemType()`, `EPSProblemType`
1035: @*/
1036: PetscErrorCode EPSGetProblemType(EPS eps,EPSProblemType *type)
1037: {
1038:   PetscFunctionBegin;
1040:   PetscAssertPointer(type,2);
1041:   *type = eps->problem_type;
1042:   PetscFunctionReturn(PETSC_SUCCESS);
1043: }

1045: /*@
1046:    EPSSetExtraction - Specifies the type of extraction technique to be employed
1047:    by the eigensolver.

1049:    Logically Collective

1051:    Input Parameters:
1052: +  eps  - the linear eigensolver context
1053: -  extr - a known type of extraction

1055:    Options Database Keys:
1056: +  -eps_ritz              - Rayleigh-Ritz extraction
1057: .  -eps_harmonic          - harmonic Ritz extraction
1058: .  -eps_harmonic_relative - harmonic Ritz extraction relative to the eigenvalue
1059: .  -eps_harmonic_right    - harmonic Ritz extraction for rightmost eigenvalues
1060: .  -eps_harmonic_largest  - harmonic Ritz extraction for largest magnitude (without target)
1061: .  -eps_refined           - refined Ritz extraction
1062: -  -eps_refined_harmonic  - refined harmonic Ritz extraction

1064:    Notes:
1065:    Not all eigensolvers support all types of extraction.

1067:    By default, a standard Rayleigh-Ritz extraction is used. Other extractions
1068:    may be useful when computing interior eigenvalues.

1070:    Harmonic-type extractions are used in combination with a target, see `EPSSetTarget()`.

1072:    Level: advanced

1074: .seealso: [](ch:eps), [](#sec:harmonic), `EPSSetTarget()`, `EPSGetExtraction()`, `EPSExtraction`
1075: @*/
1076: PetscErrorCode EPSSetExtraction(EPS eps,EPSExtraction extr)
1077: {
1078:   PetscFunctionBegin;
1081:   if (eps->extraction != extr) {
1082:     eps->state      = EPS_STATE_INITIAL;
1083:     eps->extraction = extr;
1084:   }
1085:   PetscFunctionReturn(PETSC_SUCCESS);
1086: }

1088: /*@
1089:    EPSGetExtraction - Gets the extraction type used by the `EPS` object.

1091:    Not Collective

1093:    Input Parameter:
1094: .  eps - the linear eigensolver context

1096:    Output Parameter:
1097: .  extr - name of extraction type

1099:    Level: advanced

1101: .seealso: [](ch:eps), `EPSSetExtraction()`, `EPSExtraction`
1102: @*/
1103: PetscErrorCode EPSGetExtraction(EPS eps,EPSExtraction *extr)
1104: {
1105:   PetscFunctionBegin;
1107:   PetscAssertPointer(extr,2);
1108:   *extr = eps->extraction;
1109:   PetscFunctionReturn(PETSC_SUCCESS);
1110: }

1112: /*@
1113:    EPSSetBalance - Specifies the balancing technique to be employed by the
1114:    eigensolver, and some parameters associated to it.

1116:    Logically Collective

1118:    Input Parameters:
1119: +  eps    - the linear eigensolver context
1120: .  bal    - the balancing method, see `EPSBalance` for possible values
1121: .  its    - number of iterations of the balancing algorithm
1122: -  cutoff - cutoff value

1124:    Options Database Keys:
1125: +  -eps_balance \<bal\>           - the balancing method, one of `none`, `oneside`, `twoside`, or `user`
1126: .  -eps_balance_its \<its\>       - number of iterations
1127: -  -eps_balance_cutoff \<cutoff\> - cutoff value

1129:    Notes:
1130:    When balancing is enabled, the solver works implicitly with matrix $DAD^{-1}$,
1131:    where $D$ is an appropriate diagonal matrix. This improves the accuracy of
1132:    the computed results in some cases, see [](sec:balancing).

1134:    Balancing makes sense only for non-Hermitian problems when the required
1135:    precision is high (i.e., a small tolerance such as `1e-14`).

1137:    By default, balancing is disabled. The two-sided method is much more
1138:    effective than the one-sided counterpart, but it requires the system
1139:    matrices to have the `MatMultTranspose()` operation defined. The methods
1140:    are described in {cite:p}`Che00`.

1142:    The parameter `its` is the number of iterations performed by the method. The
1143:    `cutoff` value is used only in the two-side variant. Use `PETSC_DETERMINE` to assign
1144:    a reasonably good value, or `PETSC_CURRENT` to leave the value unchanged.

1146:    User-defined balancing is allowed provided that the corresponding matrix
1147:    is set via `STSetBalanceMatrix()`.

1149:    Level: intermediate

1151: .seealso: [](ch:eps), [](sec:balancing), `EPSGetBalance()`, `EPSBalance`, `STSetBalanceMatrix()`
1152: @*/
1153: PetscErrorCode EPSSetBalance(EPS eps,EPSBalance bal,PetscInt its,PetscReal cutoff)
1154: {
1155:   PetscFunctionBegin;
1160:   switch (bal) {
1161:     case EPS_BALANCE_NONE:
1162:     case EPS_BALANCE_ONESIDE:
1163:     case EPS_BALANCE_TWOSIDE:
1164:     case EPS_BALANCE_USER:
1165:       if (eps->balance != bal) {
1166:         eps->state = EPS_STATE_INITIAL;
1167:         eps->balance = bal;
1168:       }
1169:       break;
1170:     default:
1171:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid value of argument 'bal'");
1172:   }
1173:   if (its==PETSC_DETERMINE) eps->balance_its = 5;
1174:   else if (its!=PETSC_CURRENT) {
1175:     PetscCheck(its>0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be > 0");
1176:     eps->balance_its = its;
1177:   }
1178:   if (cutoff==(PetscReal)PETSC_DETERMINE) eps->balance_cutoff = 1e-8;
1179:   else if (cutoff!=(PetscReal)PETSC_CURRENT) {
1180:     PetscCheck(cutoff>0.0,PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of cutoff. Must be > 0");
1181:     eps->balance_cutoff = cutoff;
1182:   }
1183:   PetscFunctionReturn(PETSC_SUCCESS);
1184: }

1186: /*@
1187:    EPSGetBalance - Gets the balancing type used by the `EPS` object, and the
1188:    associated parameters.

1190:    Not Collective

1192:    Input Parameter:
1193: .  eps - the linear eigensolver context

1195:    Output Parameters:
1196: +  bal    - the balancing method
1197: .  its    - number of iterations of the balancing algorithm
1198: -  cutoff - cutoff value

1200:    Level: intermediate

1202:    Note:
1203:    The user can specify `NULL` for any parameter that is not needed.

1205: .seealso: [](ch:eps), `EPSSetBalance()`, `EPSBalance`
1206: @*/
1207: PetscErrorCode EPSGetBalance(EPS eps,EPSBalance *bal,PetscInt *its,PetscReal *cutoff)
1208: {
1209:   PetscFunctionBegin;
1211:   if (bal)    *bal = eps->balance;
1212:   if (its)    *its = eps->balance_its;
1213:   if (cutoff) *cutoff = eps->balance_cutoff;
1214:   PetscFunctionReturn(PETSC_SUCCESS);
1215: }

1217: /*@
1218:    EPSSetTwoSided - Sets the solver to use a two-sided variant so that left
1219:    eigenvectors are also computed.

1221:    Logically Collective

1223:    Input Parameters:
1224: +  eps      - the linear eigensolver context
1225: -  twosided - whether the two-sided variant is to be used or not

1227:    Options Database Key:
1228: .  -eps_two_sided - toggles the twosided flag

1230:    Notes:
1231:    If the user sets `twosided`=`PETSC_TRUE` then the solver uses a variant of
1232:    the algorithm that computes both right and left eigenvectors. This is
1233:    usually much more costly. This option is not available in all solvers,
1234:    see table [](#tab:support).

1236:    When using two-sided solvers, the problem matrices must have both the
1237:    `MATOP_MULT` and `MATOP_MULT_TRANSPOSE` operations defined.

1239:    Level: advanced

1241: .seealso: [](ch:eps), `EPSGetTwoSided()`, `EPSGetLeftEigenvector()`
1242: @*/
1243: PetscErrorCode EPSSetTwoSided(EPS eps,PetscBool twosided)
1244: {
1245:   PetscFunctionBegin;
1248:   if (twosided!=eps->twosided) {
1249:     eps->twosided = twosided;
1250:     eps->state    = EPS_STATE_INITIAL;
1251:   }
1252:   PetscFunctionReturn(PETSC_SUCCESS);
1253: }

1255: /*@
1256:    EPSGetTwoSided - Returns the flag indicating whether a two-sided variant
1257:    of the algorithm is being used or not.

1259:    Not Collective

1261:    Input Parameter:
1262: .  eps - the linear eigensolver context

1264:    Output Parameter:
1265: .  twosided - the returned flag

1267:    Level: advanced

1269: .seealso: [](ch:eps), `EPSSetTwoSided()`
1270: @*/
1271: PetscErrorCode EPSGetTwoSided(EPS eps,PetscBool *twosided)
1272: {
1273:   PetscFunctionBegin;
1275:   PetscAssertPointer(twosided,2);
1276:   *twosided = eps->twosided;
1277:   PetscFunctionReturn(PETSC_SUCCESS);
1278: }

1280: /*@
1281:    EPSSetTrueResidual - Specifies if the solver must compute the true residual
1282:    explicitly or not.

1284:    Logically Collective

1286:    Input Parameters:
1287: +  eps     - the linear eigensolver context
1288: -  trueres - whether true residuals are required or not

1290:    Options Database Key:
1291: .  -eps_true_residual - toggles the true residual

1293:    Notes:
1294:    If the user sets `trueres`=`PETSC_TRUE` then the solver explicitly computes
1295:    the true residual for each eigenpair approximation, and uses it for
1296:    convergence testing. Computing the residual is usually an expensive
1297:    operation. Some solvers (e.g., Krylov solvers) can avoid this computation
1298:    by using a cheap estimate of the residual norm, but this may sometimes
1299:    give inaccurate results (especially if a spectral transform is being
1300:    used). On the contrary, preconditioned eigensolvers (e.g., Davidson solvers)
1301:    do rely on computing the true residual, so this option is irrelevant for them.

1303:    Level: advanced

1305: .seealso: [](ch:eps), `EPSGetTrueResidual()`
1306: @*/
1307: PetscErrorCode EPSSetTrueResidual(EPS eps,PetscBool trueres)
1308: {
1309:   PetscFunctionBegin;
1312:   eps->trueres = trueres;
1313:   PetscFunctionReturn(PETSC_SUCCESS);
1314: }

1316: /*@
1317:    EPSGetTrueResidual - Returns the flag indicating whether true
1318:    residuals must be computed explicitly or not.

1320:    Not Collective

1322:    Input Parameter:
1323: .  eps - the linear eigensolver context

1325:    Output Parameter:
1326: .  trueres - the returned flag

1328:    Level: advanced

1330: .seealso: [](ch:eps), `EPSSetTrueResidual()`
1331: @*/
1332: PetscErrorCode EPSGetTrueResidual(EPS eps,PetscBool *trueres)
1333: {
1334:   PetscFunctionBegin;
1336:   PetscAssertPointer(trueres,2);
1337:   *trueres = eps->trueres;
1338:   PetscFunctionReturn(PETSC_SUCCESS);
1339: }

1341: /*@
1342:    EPSSetTrackAll - Specifies if the solver must compute the residual norm of all
1343:    approximate eigenpairs or not.

1345:    Logically Collective

1347:    Input Parameters:
1348: +  eps      - the linear eigensolver context
1349: -  trackall - whether to compute all residuals or not

1351:    Notes:
1352:    If the user sets `trackall`=`PETSC_TRUE` then the solver computes (or estimates)
1353:    the residual norm for each eigenpair approximation. Computing the residual is
1354:    usually an expensive operation and solvers commonly compute only the residual
1355:    associated to the first unconverged eigenpair.

1357:    The option `-eps_monitor_all` automatically activates this option.

1359:    Level: developer

1361: .seealso: [](ch:eps), `EPSGetTrackAll()`
1362: @*/
1363: PetscErrorCode EPSSetTrackAll(EPS eps,PetscBool trackall)
1364: {
1365:   PetscFunctionBegin;
1368:   eps->trackall = trackall;
1369:   PetscFunctionReturn(PETSC_SUCCESS);
1370: }

1372: /*@
1373:    EPSGetTrackAll - Returns the flag indicating whether all residual norms must
1374:    be computed or not.

1376:    Not Collective

1378:    Input Parameter:
1379: .  eps - the linear eigensolver context

1381:    Output Parameter:
1382: .  trackall - the returned flag

1384:    Level: developer

1386: .seealso: [](ch:eps), `EPSSetTrackAll()`
1387: @*/
1388: PetscErrorCode EPSGetTrackAll(EPS eps,PetscBool *trackall)
1389: {
1390:   PetscFunctionBegin;
1392:   PetscAssertPointer(trackall,2);
1393:   *trackall = eps->trackall;
1394:   PetscFunctionReturn(PETSC_SUCCESS);
1395: }

1397: /*@
1398:    EPSSetPurify - Disable eigenvector purification (which is enabled by default).

1400:    Logically Collective

1402:    Input Parameters:
1403: +  eps    - the linear eigensolver context
1404: -  purify - whether purification is done or not, use `PETSC_FALSE` to disable it

1406:    Options Database Key:
1407: .  -eps_purify - toggles the purification flag

1409:    Notes:
1410:    By default, eigenvectors of generalized symmetric eigenproblems are purified
1411:    in order to purge directions in the nullspace of matrix $B$. If the user knows
1412:    that $B$ is non-singular, then purification can be safely deactivated and some
1413:    computational cost is avoided (this is particularly important in interval computations).

1415:    More details are given in section [](#sec:purif).

1417:    Level: intermediate

1419: .seealso: [](ch:eps), [](#sec:purif), `EPSGetPurify()`, `EPSSetInterval()`
1420: @*/
1421: PetscErrorCode EPSSetPurify(EPS eps,PetscBool purify)
1422: {
1423:   PetscFunctionBegin;
1426:   if (purify!=eps->purify) {
1427:     eps->purify = purify;
1428:     eps->state  = EPS_STATE_INITIAL;
1429:   }
1430:   PetscFunctionReturn(PETSC_SUCCESS);
1431: }

1433: /*@
1434:    EPSGetPurify - Returns the flag indicating whether purification is activated
1435:    or not.

1437:    Not Collective

1439:    Input Parameter:
1440: .  eps - the linear eigensolver context

1442:    Output Parameter:
1443: .  purify - the returned flag

1445:    Level: intermediate

1447: .seealso: [](ch:eps), `EPSSetPurify()`
1448: @*/
1449: PetscErrorCode EPSGetPurify(EPS eps,PetscBool *purify)
1450: {
1451:   PetscFunctionBegin;
1453:   PetscAssertPointer(purify,2);
1454:   *purify = eps->purify;
1455:   PetscFunctionReturn(PETSC_SUCCESS);
1456: }

1458: /*@
1459:    EPSSetOptionsPrefix - Sets the prefix used for searching for all
1460:    `EPS` options in the database.

1462:    Logically Collective

1464:    Input Parameters:
1465: +  eps    - the linear eigensolver context
1466: -  prefix - the prefix string to prepend to all `EPS` option requests

1468:    Notes:
1469:    A hyphen (-) must NOT be given at the beginning of the prefix name.
1470:    The first character of all runtime options is AUTOMATICALLY the
1471:    hyphen.

1473:    For example, to distinguish between the runtime options for two
1474:    different `EPS` contexts, one could call
1475: .vb
1476:    EPSSetOptionsPrefix(eps1,"eig1_")
1477:    EPSSetOptionsPrefix(eps2,"eig2_")
1478: .ve

1480:    Level: advanced

1482: .seealso: [](ch:eps), `EPSAppendOptionsPrefix()`, `EPSGetOptionsPrefix()`
1483: @*/
1484: PetscErrorCode EPSSetOptionsPrefix(EPS eps,const char prefix[])
1485: {
1486:   PetscFunctionBegin;
1488:   if (!eps->st) PetscCall(EPSGetST(eps,&eps->st));
1489:   PetscCall(STSetOptionsPrefix(eps->st,prefix));
1490:   if (!eps->V) PetscCall(EPSGetBV(eps,&eps->V));
1491:   PetscCall(BVSetOptionsPrefix(eps->V,prefix));
1492:   if (!eps->ds) PetscCall(EPSGetDS(eps,&eps->ds));
1493:   PetscCall(DSSetOptionsPrefix(eps->ds,prefix));
1494:   if (!eps->rg) PetscCall(EPSGetRG(eps,&eps->rg));
1495:   PetscCall(RGSetOptionsPrefix(eps->rg,prefix));
1496:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)eps,prefix));
1497:   PetscFunctionReturn(PETSC_SUCCESS);
1498: }

1500: /*@
1501:    EPSAppendOptionsPrefix - Appends to the prefix used for searching for all
1502:    `EPS` options in the database.

1504:    Logically Collective

1506:    Input Parameters:
1507: +  eps    - the linear eigensolver context
1508: -  prefix - the prefix string to prepend to all `EPS` option requests

1510:    Notes:
1511:    A hyphen (-) must NOT be given at the beginning of the prefix name.
1512:    The first character of all runtime options is AUTOMATICALLY the hyphen.

1514:    Level: advanced

1516: .seealso: [](ch:eps), `EPSSetOptionsPrefix()`, `EPSGetOptionsPrefix()`
1517: @*/
1518: PetscErrorCode EPSAppendOptionsPrefix(EPS eps,const char prefix[])
1519: {
1520:   PetscFunctionBegin;
1522:   if (!eps->st) PetscCall(EPSGetST(eps,&eps->st));
1523:   PetscCall(STAppendOptionsPrefix(eps->st,prefix));
1524:   if (!eps->V) PetscCall(EPSGetBV(eps,&eps->V));
1525:   PetscCall(BVAppendOptionsPrefix(eps->V,prefix));
1526:   if (!eps->ds) PetscCall(EPSGetDS(eps,&eps->ds));
1527:   PetscCall(DSAppendOptionsPrefix(eps->ds,prefix));
1528:   if (!eps->rg) PetscCall(EPSGetRG(eps,&eps->rg));
1529:   PetscCall(RGAppendOptionsPrefix(eps->rg,prefix));
1530:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)eps,prefix));
1531:   PetscFunctionReturn(PETSC_SUCCESS);
1532: }

1534: /*@
1535:    EPSGetOptionsPrefix - Gets the prefix used for searching for all
1536:    `EPS` options in the database.

1538:    Not Collective

1540:    Input Parameter:
1541: .  eps - the linear eigensolver context

1543:    Output Parameter:
1544: .  prefix - pointer to the prefix string used is returned

1546:    Level: advanced

1548: .seealso: [](ch:eps), `EPSSetOptionsPrefix()`, `EPSAppendOptionsPrefix()`
1549: @*/
1550: PetscErrorCode EPSGetOptionsPrefix(EPS eps,const char *prefix[])
1551: {
1552:   PetscFunctionBegin;
1554:   PetscAssertPointer(prefix,2);
1555:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)eps,prefix));
1556:   PetscFunctionReturn(PETSC_SUCCESS);
1557: }