Date: 2020-01-13T12:00:04+00:00

Actual source code: epsopts.c
slepc-3.12.2 2020-01-13
Report Typos and Errors

      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2019, 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>   /*I "slepceps.h" I*/
     16: #include <petscdraw.h>

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

     22:    Collective on eps

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

     32:    Level: developer

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

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

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

     61:    Collective on eps

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

     70:    Level: developer

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

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

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

     97:    Collective on eps

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

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

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

    120:   EPSRegisterAll();
    121:   PetscObjectOptionsBegin((PetscObject)eps);
    122:     PetscOptionsFList("-eps_type","Eigensolver method","EPSSetType",EPSList,(char*)(((PetscObject)eps)->type_name?((PetscObject)eps)->type_name:EPSKRYLOVSCHUR),type,256,&flg);
    123:     if (flg) {
    124:       EPSSetType(eps,type);
    125:     } else if (!((PetscObject)eps)->type_name) {
    126:       EPSSetType(eps,EPSKRYLOVSCHUR);
    127:     }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    298:    Not Collective

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

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

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

    310:    Level: intermediate

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

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

    327:    Logically Collective on eps

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

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

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

    341:    Level: intermediate

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

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

    372:    Not Collective

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

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

    382:    Level: intermediate

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

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

    400:    Logically Collective on eps

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

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

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

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

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

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

    430:    Level: intermediate

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

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

    463:    Logically Collective on eps

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

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

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

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

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

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

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

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

    514:    Level: intermediate

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

    549: /*@
    550:    EPSGetWhichEigenpairs - Returns which portion of the spectrum is to be
    551:    sought.

    553:    Not Collective

    555:    Input Parameter:
    556: .  eps - eigensolver context obtained from EPSCreate()

    558:    Output Parameter:
    559: .  which - the portion of the spectrum to be sought

    561:    Notes:
    562:    See EPSSetWhichEigenpairs() for possible values of 'which'.

    564:    Level: intermediate

    566: .seealso: EPSSetWhichEigenpairs(), EPSWhich
    567: @*/
    568: PetscErrorCode EPSGetWhichEigenpairs(EPS eps,EPSWhich *which)
    569: {
    573:   *which = eps->which;
    574:   return(0);
    575: }

    577: /*@C
    578:    EPSSetEigenvalueComparison - Specifies the eigenvalue comparison function
    579:    when EPSSetWhichEigenpairs() is set to EPS_WHICH_USER.

    581:    Logically Collective on eps

    583:    Input Parameters:
    584: +  eps  - eigensolver context obtained from EPSCreate()
    585: .  func - a pointer to the comparison function
    586: -  ctx  - a context pointer (the last parameter to the comparison function)

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

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

    598:    Note:
    599:    The returning parameter 'res' can be
    600: +  negative - if the 1st eigenvalue is preferred to the 2st one
    601: .  zero     - if both eigenvalues are equally preferred
    602: -  positive - if the 2st eigenvalue is preferred to the 1st one

    604:    Level: advanced

    606: .seealso: EPSSetWhichEigenpairs(), EPSWhich
    607: @*/
    608: PetscErrorCode EPSSetEigenvalueComparison(EPS eps,PetscErrorCode (*func)(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*),void* ctx)
    609: {
    612:   eps->sc->comparison    = func;
    613:   eps->sc->comparisonctx = ctx;
    614:   eps->which             = EPS_WHICH_USER;
    615:   return(0);
    616: }

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

    623:    Logically Collective on eps

    625:    Input Parameters:
    626: +  eps  - eigensolver context obtained from EPSCreate()
    627: .  func - a pointer to the evaluation function
    628: -  ctx  - a context pointer (the last parameter to the evaluation function)

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

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

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

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

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

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

    661:    Level: advanced

    663: .seealso: EPSSetWhichEigenpairs()
    664: @*/
    665: PetscErrorCode EPSSetArbitrarySelection(EPS eps,PetscErrorCode (*func)(PetscScalar,PetscScalar,Vec,Vec,PetscScalar*,PetscScalar*,void*),void* ctx)
    666: {
    669:   eps->arbitrary    = func;
    670:   eps->arbitraryctx = ctx;
    671:   eps->state        = EPS_STATE_INITIAL;
    672:   return(0);
    673: }

    675: /*@C
    676:    EPSSetConvergenceTestFunction - Sets a function to compute the error estimate
    677:    used in the convergence test.

    679:    Logically Collective on eps

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

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

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

    697:    Note:
    698:    If the error estimate returned by the convergence test function is less than
    699:    the tolerance, then the eigenvalue is accepted as converged.

    701:    Level: advanced

    703: .seealso: EPSSetConvergenceTest(), EPSSetTolerances()
    704: @*/
    705: PetscErrorCode EPSSetConvergenceTestFunction(EPS eps,PetscErrorCode (*func)(EPS,PetscScalar,PetscScalar,PetscReal,PetscReal*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    706: {

    711:   if (eps->convergeddestroy) {
    712:     (*eps->convergeddestroy)(eps->convergedctx);
    713:   }
    714:   eps->convergeduser    = func;
    715:   eps->convergeddestroy = destroy;
    716:   eps->convergedctx     = ctx;
    717:   if (func == EPSConvergedRelative) eps->conv = EPS_CONV_REL;
    718:   else if (func == EPSConvergedNorm) eps->conv = EPS_CONV_NORM;
    719:   else if (func == EPSConvergedAbsolute) eps->conv = EPS_CONV_ABS;
    720:   else {
    721:     eps->conv      = EPS_CONV_USER;
    722:     eps->converged = eps->convergeduser;
    723:   }
    724:   return(0);
    725: }

    727: /*@
    728:    EPSSetConvergenceTest - Specifies how to compute the error estimate
    729:    used in the convergence test.

    731:    Logically Collective on eps

    733:    Input Parameters:
    734: +  eps  - eigensolver context obtained from EPSCreate()
    735: -  conv - the type of convergence test

    737:    Options Database Keys:
    738: +  -eps_conv_abs  - Sets the absolute convergence test
    739: .  -eps_conv_rel  - Sets the convergence test relative to the eigenvalue
    740: .  -eps_conv_norm - Sets the convergence test relative to the matrix norms
    741: -  -eps_conv_user - Selects the user-defined convergence test

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

    750:    Level: intermediate

    752: .seealso: EPSGetConvergenceTest(), EPSSetConvergenceTestFunction(), EPSSetStoppingTest(), EPSConv
    753: @*/
    754: PetscErrorCode EPSSetConvergenceTest(EPS eps,EPSConv conv)
    755: {
    759:   switch (conv) {
    760:     case EPS_CONV_ABS:  eps->converged = EPSConvergedAbsolute; break;
    761:     case EPS_CONV_REL:  eps->converged = EPSConvergedRelative; break;
    762:     case EPS_CONV_NORM: eps->converged = EPSConvergedNorm; break;
    763:     case EPS_CONV_USER:
    764:       if (!eps->convergeduser) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ORDER,"Must call EPSSetConvergenceTestFunction() first");
    765:       eps->converged = eps->convergeduser;
    766:       break;
    767:     default:
    768:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'conv' value");
    769:   }
    770:   eps->conv = conv;
    771:   return(0);
    772: }

    774: /*@
    775:    EPSGetConvergenceTest - Gets the method used to compute the error estimate
    776:    used in the convergence test.

    778:    Not Collective

    780:    Input Parameters:
    781: .  eps   - eigensolver context obtained from EPSCreate()

    783:    Output Parameters:
    784: .  conv  - the type of convergence test

    786:    Level: intermediate

    788: .seealso: EPSSetConvergenceTest(), EPSConv
    789: @*/
    790: PetscErrorCode EPSGetConvergenceTest(EPS eps,EPSConv *conv)
    791: {
    795:   *conv = eps->conv;
    796:   return(0);
    797: }

    799: /*@C
    800:    EPSSetStoppingTestFunction - Sets a function to decide when to stop the outer
    801:    iteration of the eigensolver.

    803:    Logically Collective on eps

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

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

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

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

    828:    Level: advanced

    830: .seealso: EPSSetStoppingTest(), EPSStoppingBasic()
    831: @*/
    832: PetscErrorCode EPSSetStoppingTestFunction(EPS eps,PetscErrorCode (*func)(EPS,PetscInt,PetscInt,PetscInt,PetscInt,EPSConvergedReason*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    833: {

    838:   if (eps->stoppingdestroy) {
    839:     (*eps->stoppingdestroy)(eps->stoppingctx);
    840:   }
    841:   eps->stoppinguser    = func;
    842:   eps->stoppingdestroy = destroy;
    843:   eps->stoppingctx     = ctx;
    844:   if (func == EPSStoppingBasic) eps->stop = EPS_STOP_BASIC;
    845:   else {
    846:     eps->stop     = EPS_STOP_USER;
    847:     eps->stopping = eps->stoppinguser;
    848:   }
    849:   return(0);
    850: }

    852: /*@
    853:    EPSSetStoppingTest - Specifies how to decide the termination of the outer
    854:    loop of the eigensolver.

    856:    Logically Collective on eps

    858:    Input Parameters:
    859: +  eps  - eigensolver context obtained from EPSCreate()
    860: -  stop - the type of stopping test

    862:    Options Database Keys:
    863: +  -eps_stop_basic - Sets the default stopping test
    864: -  -eps_stop_user  - Selects the user-defined stopping test

    866:    Note:
    867:    The parameter 'stop' can have one of these values
    868: +     EPS_STOP_BASIC - default stopping test
    869: -     EPS_STOP_USER  - function set by EPSSetStoppingTestFunction()

    871:    Level: advanced

    873: .seealso: EPSGetStoppingTest(), EPSSetStoppingTestFunction(), EPSSetConvergenceTest(), EPSStop
    874: @*/
    875: PetscErrorCode EPSSetStoppingTest(EPS eps,EPSStop stop)
    876: {
    880:   switch (stop) {
    881:     case EPS_STOP_BASIC: eps->stopping = EPSStoppingBasic; break;
    882:     case EPS_STOP_USER:
    883:       if (!eps->stoppinguser) SETERRQ(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:   return(0);
    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 Parameters:
    900: .  eps   - eigensolver context obtained from EPSCreate()

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

    905:    Level: advanced

    907: .seealso: EPSSetStoppingTest(), EPSStop
    908: @*/
    909: PetscErrorCode EPSGetStoppingTest(EPS eps,EPSStop *stop)
    910: {
    914:   *stop = eps->stop;
    915:   return(0);
    916: }

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

    921:    Logically Collective on eps

    923:    Input Parameters:
    924: +  eps      - the 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

    935:    Notes:
    936:    Allowed values for the problem type are: Hermitian (EPS_HEP), non-Hermitian
    937:    (EPS_NHEP), generalized Hermitian (EPS_GHEP), generalized non-Hermitian
    938:    (EPS_GNHEP), generalized non-Hermitian with positive semi-definite B
    939:    (EPS_PGNHEP), and generalized Hermitian-indefinite (EPS_GHIEP).

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

    948:    Level: intermediate

    950: .seealso: EPSSetOperators(), EPSSetType(), EPSGetProblemType(), EPSProblemType
    951: @*/
    952: PetscErrorCode EPSSetProblemType(EPS eps,EPSProblemType type)
    953: {
    957:   if (type == eps->problem_type) return(0);
    958:   switch (type) {
    959:     case EPS_HEP:
    960:       eps->isgeneralized = PETSC_FALSE;
    961:       eps->ishermitian = PETSC_TRUE;
    962:       eps->ispositive = PETSC_FALSE;
    963:       break;
    964:     case EPS_NHEP:
    965:       eps->isgeneralized = PETSC_FALSE;
    966:       eps->ishermitian = PETSC_FALSE;
    967:       eps->ispositive = PETSC_FALSE;
    968:       break;
    969:     case EPS_GHEP:
    970:       eps->isgeneralized = PETSC_TRUE;
    971:       eps->ishermitian = PETSC_TRUE;
    972:       eps->ispositive = PETSC_TRUE;
    973:       break;
    974:     case EPS_GNHEP:
    975:       eps->isgeneralized = PETSC_TRUE;
    976:       eps->ishermitian = PETSC_FALSE;
    977:       eps->ispositive = PETSC_FALSE;
    978:       break;
    979:     case EPS_PGNHEP:
    980:       eps->isgeneralized = PETSC_TRUE;
    981:       eps->ishermitian = PETSC_FALSE;
    982:       eps->ispositive = PETSC_TRUE;
    983:       break;
    984:     case EPS_GHIEP:
    985:       eps->isgeneralized = PETSC_TRUE;
    986:       eps->ishermitian = PETSC_TRUE;
    987:       eps->ispositive = PETSC_FALSE;
    988:       break;
    989:     default:
    990:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"Unknown eigenvalue problem type");
    991:   }
    992:   eps->problem_type = type;
    993:   eps->state = EPS_STATE_INITIAL;
    994:   return(0);
    995: }

    997: /*@
    998:    EPSGetProblemType - Gets the problem type from the EPS object.

    1000:    Not Collective

    1002:    Input Parameter:
    1003: .  eps - the eigensolver context

    1005:    Output Parameter:
    1006: .  type - the problem type

    1008:    Level: intermediate

    1010: .seealso: EPSSetProblemType(), EPSProblemType
    1011: @*/
    1012: PetscErrorCode EPSGetProblemType(EPS eps,EPSProblemType *type)
    1013: {
    1017:   *type = eps->problem_type;
    1018:   return(0);
    1019: }

    1021: /*@
    1022:    EPSSetExtraction - Specifies the type of extraction technique to be employed
    1023:    by the eigensolver.

    1025:    Logically Collective on eps

    1027:    Input Parameters:
    1028: +  eps  - the eigensolver context
    1029: -  extr - a known type of extraction

    1031:    Options Database Keys:
    1032: +  -eps_ritz - Rayleigh-Ritz extraction
    1033: .  -eps_harmonic - harmonic Ritz extraction
    1034: .  -eps_harmonic_relative - harmonic Ritz extraction relative to the eigenvalue
    1035: .  -eps_harmonic_right - harmonic Ritz extraction for rightmost eigenvalues
    1036: .  -eps_harmonic_largest - harmonic Ritz extraction for largest magnitude
    1037:    (without target)
    1038: .  -eps_refined - refined Ritz extraction
    1039: -  -eps_refined_harmonic - refined harmonic Ritz extraction

    1041:    Notes:
    1042:    Not all eigensolvers support all types of extraction. See the SLEPc
    1043:    Users Manual for details.

    1045:    By default, a standard Rayleigh-Ritz extraction is used. Other extractions
    1046:    may be useful when computing interior eigenvalues.

    1048:    Harmonic-type extractions are used in combination with a 'target'.

    1050:    Level: advanced

    1052: .seealso: EPSSetTarget(), EPSGetExtraction(), EPSExtraction
    1053: @*/
    1054: PetscErrorCode EPSSetExtraction(EPS eps,EPSExtraction extr)
    1055: {
    1059:   eps->extraction = extr;
    1060:   return(0);
    1061: }

    1063: /*@
    1064:    EPSGetExtraction - Gets the extraction type used by the EPS object.

    1066:    Not Collective

    1068:    Input Parameter:
    1069: .  eps - the eigensolver context

    1071:    Output Parameter:
    1072: .  extr - name of extraction type

    1074:    Level: advanced

    1076: .seealso: EPSSetExtraction(), EPSExtraction
    1077: @*/
    1078: PetscErrorCode EPSGetExtraction(EPS eps,EPSExtraction *extr)
    1079: {
    1083:   *extr = eps->extraction;
    1084:   return(0);
    1085: }

    1087: /*@
    1088:    EPSSetBalance - Specifies the balancing technique to be employed by the
    1089:    eigensolver, and some parameters associated to it.

    1091:    Logically Collective on eps

    1093:    Input Parameters:
    1094: +  eps    - the eigensolver context
    1095: .  bal    - the balancing method, one of EPS_BALANCE_NONE, EPS_BALANCE_ONESIDE,
    1096:             EPS_BALANCE_TWOSIDE, or EPS_BALANCE_USER
    1097: .  its    - number of iterations of the balancing algorithm
    1098: -  cutoff - cutoff value

    1100:    Options Database Keys:
    1101: +  -eps_balance <method> - the balancing method, where <method> is one of
    1102:                            'none', 'oneside', 'twoside', or 'user'
    1103: .  -eps_balance_its <its> - number of iterations
    1104: -  -eps_balance_cutoff <cutoff> - cutoff value

    1106:    Notes:
    1107:    When balancing is enabled, the solver works implicitly with matrix DAD^-1,
    1108:    where D is an appropriate diagonal matrix. This improves the accuracy of
    1109:    the computed results in some cases. See the SLEPc Users Manual for details.

    1111:    Balancing makes sense only for non-Hermitian problems when the required
    1112:    precision is high (i.e. a small tolerance such as 1e-15).

    1114:    By default, balancing is disabled. The two-sided method is much more
    1115:    effective than the one-sided counterpart, but it requires the system
    1116:    matrices to have the MatMultTranspose operation defined.

    1118:    The parameter 'its' is the number of iterations performed by the method. The
    1119:    cutoff value is used only in the two-side variant. Use PETSC_DEFAULT to assign
    1120:    a reasonably good value.

    1122:    User-defined balancing is allowed provided that the corresponding matrix
    1123:    is set via STSetBalanceMatrix.

    1125:    Level: intermediate

    1127: .seealso: EPSGetBalance(), EPSBalance, STSetBalanceMatrix()
    1128: @*/
    1129: PetscErrorCode EPSSetBalance(EPS eps,EPSBalance bal,PetscInt its,PetscReal cutoff)
    1130: {
    1136:   switch (bal) {
    1137:     case EPS_BALANCE_NONE:
    1138:     case EPS_BALANCE_ONESIDE:
    1139:     case EPS_BALANCE_TWOSIDE:
    1140:     case EPS_BALANCE_USER:
    1141:       if (eps->balance != bal) {
    1142:         eps->state = EPS_STATE_INITIAL;
    1143:         eps->balance = bal;
    1144:       }
    1145:       break;
    1146:     default:
    1147:       SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Invalid value of argument 'bal'");
    1148:   }
    1149:   if (its==PETSC_DECIDE || its==PETSC_DEFAULT) eps->balance_its = 5;
    1150:   else {
    1151:     if (its <= 0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be > 0");
    1152:     eps->balance_its = its;
    1153:   }
    1154:   if (cutoff==PETSC_DECIDE || cutoff==PETSC_DEFAULT) eps->balance_cutoff = 1e-8;
    1155:   else {
    1156:     if (cutoff <= 0.0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of cutoff. Must be > 0");
    1157:     eps->balance_cutoff = cutoff;
    1158:   }
    1159:   return(0);
    1160: }

    1162: /*@C
    1163:    EPSGetBalance - Gets the balancing type used by the EPS object, and the
    1164:    associated parameters.

    1166:    Not Collective

    1168:    Input Parameter:
    1169: .  eps - the eigensolver context

    1171:    Output Parameters:
    1172: +  bal    - the balancing method
    1173: .  its    - number of iterations of the balancing algorithm
    1174: -  cutoff - cutoff value

    1176:    Level: intermediate

    1178:    Note:
    1179:    The user can specify NULL for any parameter that is not needed.

    1181: .seealso: EPSSetBalance(), EPSBalance
    1182: @*/
    1183: PetscErrorCode EPSGetBalance(EPS eps,EPSBalance *bal,PetscInt *its,PetscReal *cutoff)
    1184: {
    1187:   if (bal)    *bal = eps->balance;
    1188:   if (its)    *its = eps->balance_its;
    1189:   if (cutoff) *cutoff = eps->balance_cutoff;
    1190:   return(0);
    1191: }

    1193: /*@
    1194:    EPSSetTwoSided - Sets the solver to use a two-sided variant so that left
    1195:    eigenvectors are also computed.

    1197:    Logically Collective on eps

    1199:    Input Parameters:
    1200: +  eps      - the eigensolver context
    1201: -  twosided - whether the two-sided variant is to be used or not

    1203:    Options Database Keys:
    1204: .  -eps_two_sided <boolean> - Sets/resets the twosided flag

    1206:    Notes:
    1207:    If the user sets twosided=PETSC_TRUE then the solver uses a variant of
    1208:    the algorithm that computes both right and left eigenvectors. This is
    1209:    usually much more costly. This option is not available in all solvers.

    1211:    When using two-sided solvers, the problem matrices must have both the
    1212:    MatMult and MatMultTranspose operations defined.

    1214:    Level: advanced

    1216: .seealso: EPSGetTwoSided(), EPSGetLeftEigenvector()
    1217: @*/
    1218: PetscErrorCode EPSSetTwoSided(EPS eps,PetscBool twosided)
    1219: {
    1223:   if (twosided!=eps->twosided) {
    1224:     eps->twosided = twosided;
    1225:     eps->state    = EPS_STATE_INITIAL;
    1226:   }
    1227:   return(0);
    1228: }

    1230: /*@
    1231:    EPSGetTwoSided - Returns the flag indicating whether a two-sided variant
    1232:    of the algorithm is being used or not.

    1234:    Not Collective

    1236:    Input Parameter:
    1237: .  eps - the eigensolver context

    1239:    Output Parameter:
    1240: .  twosided - the returned flag

    1242:    Level: advanced

    1244: .seealso: EPSSetTwoSided()
    1245: @*/
    1246: PetscErrorCode EPSGetTwoSided(EPS eps,PetscBool *twosided)
    1247: {
    1251:   *twosided = eps->twosided;
    1252:   return(0);
    1253: }

    1255: /*@
    1256:    EPSSetTrueResidual - Specifies if the solver must compute the true residual
    1257:    explicitly or not.

    1259:    Logically Collective on eps

    1261:    Input Parameters:
    1262: +  eps     - the eigensolver context
    1263: -  trueres - whether true residuals are required or not

    1265:    Options Database Keys:
    1266: .  -eps_true_residual <boolean> - Sets/resets the boolean flag 'trueres'

    1268:    Notes:
    1269:    If the user sets trueres=PETSC_TRUE then the solver explicitly computes
    1270:    the true residual for each eigenpair approximation, and uses it for
    1271:    convergence testing. Computing the residual is usually an expensive
    1272:    operation. Some solvers (e.g., Krylov solvers) can avoid this computation
    1273:    by using a cheap estimate of the residual norm, but this may sometimes
    1274:    give inaccurate results (especially if a spectral transform is being
    1275:    used). On the contrary, preconditioned eigensolvers (e.g., Davidson solvers)
    1276:    do rely on computing the true residual, so this option is irrelevant for them.

    1278:    Level: advanced

    1280: .seealso: EPSGetTrueResidual()
    1281: @*/
    1282: PetscErrorCode EPSSetTrueResidual(EPS eps,PetscBool trueres)
    1283: {
    1287:   eps->trueres = trueres;
    1288:   return(0);
    1289: }

    1291: /*@
    1292:    EPSGetTrueResidual - Returns the flag indicating whether true
    1293:    residuals must be computed explicitly or not.

    1295:    Not Collective

    1297:    Input Parameter:
    1298: .  eps - the eigensolver context

    1300:    Output Parameter:
    1301: .  trueres - the returned flag

    1303:    Level: advanced

    1305: .seealso: EPSSetTrueResidual()
    1306: @*/
    1307: PetscErrorCode EPSGetTrueResidual(EPS eps,PetscBool *trueres)
    1308: {
    1312:   *trueres = eps->trueres;
    1313:   return(0);
    1314: }

    1316: /*@
    1317:    EPSSetTrackAll - Specifies if the solver must compute the residual norm of all
    1318:    approximate eigenpairs or not.

    1320:    Logically Collective on eps

    1322:    Input Parameters:
    1323: +  eps      - the eigensolver context
    1324: -  trackall - whether to compute all residuals or not

    1326:    Notes:
    1327:    If the user sets trackall=PETSC_TRUE then the solver computes (or estimates)
    1328:    the residual norm for each eigenpair approximation. Computing the residual is
    1329:    usually an expensive operation and solvers commonly compute only the residual
    1330:    associated to the first unconverged eigenpair.

    1332:    The options '-eps_monitor_all' and '-eps_monitor_lg_all' automatically
    1333:    activate this option.

    1335:    Level: developer

    1337: .seealso: EPSGetTrackAll()
    1338: @*/
    1339: PetscErrorCode EPSSetTrackAll(EPS eps,PetscBool trackall)
    1340: {
    1344:   eps->trackall = trackall;
    1345:   return(0);
    1346: }

    1348: /*@
    1349:    EPSGetTrackAll - Returns the flag indicating whether all residual norms must
    1350:    be computed or not.

    1352:    Not Collective

    1354:    Input Parameter:
    1355: .  eps - the eigensolver context

    1357:    Output Parameter:
    1358: .  trackall - the returned flag

    1360:    Level: developer

    1362: .seealso: EPSSetTrackAll()
    1363: @*/
    1364: PetscErrorCode EPSGetTrackAll(EPS eps,PetscBool *trackall)
    1365: {
    1369:   *trackall = eps->trackall;
    1370:   return(0);
    1371: }

    1373: /*@
    1374:    EPSSetPurify - Deactivate eigenvector purification (which is activated by default).

    1376:    Logically Collective on eps

    1378:    Input Parameters:
    1379: +  eps    - the eigensolver context
    1380: -  purify - whether purification is required or not

    1382:    Options Database Keys:
    1383: .  -eps_purify <boolean> - Sets/resets the boolean flag 'purify'

    1385:    Notes:
    1386:    By default, eigenvectors of generalized symmetric eigenproblems are purified
    1387:    in order to purge directions in the nullspace of matrix B. If the user knows
    1388:    that B is non-singular, then purification can be safely deactivated and some
    1389:    computational cost is avoided (this is particularly important in interval computations).

    1391:    Level: intermediate

    1393: .seealso: EPSGetPurify(), EPSSetInterval()
    1394: @*/
    1395: PetscErrorCode EPSSetPurify(EPS eps,PetscBool purify)
    1396: {
    1400:   if (purify!=eps->purify) {
    1401:     eps->purify = purify;
    1402:     eps->state  = EPS_STATE_INITIAL;
    1403:   }
    1404:   return(0);
    1405: }

    1407: /*@
    1408:    EPSGetPurify - Returns the flag indicating whether purification is activated
    1409:    or not.

    1411:    Not Collective

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

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

    1419:    Level: intermediate

    1421: .seealso: EPSSetPurify()
    1422: @*/
    1423: PetscErrorCode EPSGetPurify(EPS eps,PetscBool *purify)
    1424: {
    1428:   *purify = eps->purify;
    1429:   return(0);
    1430: }

    1432: /*@C
    1433:    EPSSetOptionsPrefix - Sets the prefix used for searching for all
    1434:    EPS options in the database.

    1436:    Logically Collective on eps

    1438:    Input Parameters:
    1439: +  eps - the eigensolver context
    1440: -  prefix - the prefix string to prepend to all EPS option requests

    1442:    Notes:
    1443:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1444:    The first character of all runtime options is AUTOMATICALLY the
    1445:    hyphen.

    1447:    For example, to distinguish between the runtime options for two
    1448:    different EPS contexts, one could call
    1449: .vb
    1450:       EPSSetOptionsPrefix(eps1,"eig1_")
    1451:       EPSSetOptionsPrefix(eps2,"eig2_")
    1452: .ve

    1454:    Level: advanced

    1456: .seealso: EPSAppendOptionsPrefix(), EPSGetOptionsPrefix()
    1457: @*/
    1458: PetscErrorCode EPSSetOptionsPrefix(EPS eps,const char *prefix)
    1459: {

    1464:   if (!eps->st) { EPSGetST(eps,&eps->st); }
    1465:   STSetOptionsPrefix(eps->st,prefix);
    1466:   if (!eps->V) { EPSGetBV(eps,&eps->V); }
    1467:   BVSetOptionsPrefix(eps->V,prefix);
    1468:   if (!eps->ds) { EPSGetDS(eps,&eps->ds); }
    1469:   DSSetOptionsPrefix(eps->ds,prefix);
    1470:   if (!eps->rg) { EPSGetRG(eps,&eps->rg); }
    1471:   RGSetOptionsPrefix(eps->rg,prefix);
    1472:   PetscObjectSetOptionsPrefix((PetscObject)eps,prefix);
    1473:   return(0);
    1474: }

    1476: /*@C
    1477:    EPSAppendOptionsPrefix - Appends to the prefix used for searching for all
    1478:    EPS options in the database.

    1480:    Logically Collective on eps

    1482:    Input Parameters:
    1483: +  eps - the eigensolver context
    1484: -  prefix - the prefix string to prepend to all EPS option requests

    1486:    Notes:
    1487:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1488:    The first character of all runtime options is AUTOMATICALLY the hyphen.

    1490:    Level: advanced

    1492: .seealso: EPSSetOptionsPrefix(), EPSGetOptionsPrefix()
    1493: @*/
    1494: PetscErrorCode EPSAppendOptionsPrefix(EPS eps,const char *prefix)
    1495: {

    1500:   if (!eps->st) { EPSGetST(eps,&eps->st); }
    1501:   STAppendOptionsPrefix(eps->st,prefix);
    1502:   if (!eps->V) { EPSGetBV(eps,&eps->V); }
    1503:   BVAppendOptionsPrefix(eps->V,prefix);
    1504:   if (!eps->ds) { EPSGetDS(eps,&eps->ds); }
    1505:   DSAppendOptionsPrefix(eps->ds,prefix);
    1506:   if (!eps->rg) { EPSGetRG(eps,&eps->rg); }
    1507:   RGAppendOptionsPrefix(eps->rg,prefix);
    1508:   PetscObjectAppendOptionsPrefix((PetscObject)eps,prefix);
    1509:   return(0);
    1510: }

    1512: /*@C
    1513:    EPSGetOptionsPrefix - Gets the prefix used for searching for all
    1514:    EPS options in the database.

    1516:    Not Collective

    1518:    Input Parameters:
    1519: .  eps - the eigensolver context

    1521:    Output Parameters:
    1522: .  prefix - pointer to the prefix string used is returned

    1524:    Note:
    1525:    On the Fortran side, the user should pass in a string 'prefix' of
    1526:    sufficient length to hold the prefix.

    1528:    Level: advanced

    1530: .seealso: EPSSetOptionsPrefix(), EPSAppendOptionsPrefix()
    1531: @*/
    1532: PetscErrorCode EPSGetOptionsPrefix(EPS eps,const char *prefix[])
    1533: {

    1539:   PetscObjectGetOptionsPrefix((PetscObject)eps,prefix);
    1540:   return(0);
    1541: }