Date: 2017-05-17T08:26:46+00:00

Actual source code: pepopts.c
slepc-3.7.4 2017-05-17
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      1: /*
      2:       PEP routines related to options that can be set via the command-line
      3:       or procedurally.

      5:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      6:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      7:    Copyright (c) 2002-2016, Universitat Politecnica de Valencia, Spain

      9:    This file is part of SLEPc.

     11:    SLEPc is free software: you can redistribute it and/or modify it under  the
     12:    terms of version 3 of the GNU Lesser General Public License as published by
     13:    the Free Software Foundation.

     15:    SLEPc  is  distributed in the hope that it will be useful, but WITHOUT  ANY
     16:    WARRANTY;  without even the implied warranty of MERCHANTABILITY or  FITNESS
     17:    FOR  A  PARTICULAR PURPOSE. See the GNU Lesser General Public  License  for
     18:    more details.

     20:    You  should have received a copy of the GNU Lesser General  Public  License
     21:    along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
     22:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     23: */

     25: #include <slepc/private/pepimpl.h>       /*I "slepcpep.h" I*/
     26: #include <petscdraw.h>

     30: /*@C
     31:    PEPMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type
     32:    indicated by the user.

     34:    Collective on PEP

     36:    Input Parameters:
     37: +  pep      - the polynomial eigensolver context
     38: .  name     - the monitor option name
     39: .  help     - message indicating what monitoring is done
     40: .  manual   - manual page for the monitor
     41: .  monitor  - the monitor function, whose context is a PetscViewerAndFormat
     42: -  trackall - whether this monitor tracks all eigenvalues or not

     44:    Level: developer

     46: .seealso: PEPMonitorSet(), PEPSetTrackAll(), PEPConvMonitorSetFromOptions()
     47: @*/
     48: PetscErrorCode PEPMonitorSetFromOptions(PEP pep,const char name[],const char help[],const char manual[],PetscErrorCode (*monitor)(PEP,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,PetscViewerAndFormat*),PetscBool trackall)
     49: {
     50:   PetscErrorCode       ierr;
     51:   PetscBool            flg;
     52:   PetscViewer          viewer;
     53:   PetscViewerFormat    format;
     54:   PetscViewerAndFormat *vf;

     57:   PetscOptionsGetViewer(PetscObjectComm((PetscObject)pep),((PetscObject)pep)->prefix,name,&viewer,&format,&flg);
     58:   if (flg) {
     59:     PetscViewerAndFormatCreate(viewer,format,&vf);
     60:     PetscObjectDereference((PetscObject)viewer);
     61:     PEPMonitorSet(pep,(PetscErrorCode (*)(PEP,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,void*))monitor,vf,(PetscErrorCode (*)(void**))PetscViewerAndFormatDestroy);
     62:     if (trackall) {
     63:       PEPSetTrackAll(pep,PETSC_TRUE);
     64:     }
     65:   }
     66:   return(0);
     67: }

     71: /*@C
     72:    PEPConvMonitorSetFromOptions - Sets a monitor function and viewer appropriate for the type
     73:    indicated by the user (for monitors that only show iteration numbers of convergence).

     75:    Collective on PEP

     77:    Input Parameters:
     78: +  pep      - the polynomial eigensolver context
     79: .  name     - the monitor option name
     80: .  help     - message indicating what monitoring is done
     81: .  manual   - manual page for the monitor
     82: -  monitor  - the monitor function, whose context is a SlepcConvMonitor

     84:    Level: developer

     86: .seealso: PEPMonitorSet(), PEPMonitorSetFromOptions()
     87: @*/
     88: PetscErrorCode PEPConvMonitorSetFromOptions(PEP pep,const char name[],const char help[],const char manual[],PetscErrorCode (*monitor)(PEP,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,SlepcConvMonitor))
     89: {
     90:   PetscErrorCode    ierr;
     91:   PetscBool         flg;
     92:   PetscViewer       viewer;
     93:   PetscViewerFormat format;
     94:   SlepcConvMonitor  ctx;

     97:   PetscOptionsGetViewer(PetscObjectComm((PetscObject)pep),((PetscObject)pep)->prefix,name,&viewer,&format,&flg);
     98:   if (flg) {
     99:     SlepcConvMonitorCreate(viewer,format,&ctx);
    100:     PetscObjectDereference((PetscObject)viewer);
    101:     PEPMonitorSet(pep,(PetscErrorCode (*)(PEP,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,void*))monitor,ctx,(PetscErrorCode (*)(void**))SlepcConvMonitorDestroy);
    102:   }
    103:   return(0);
    104: }

    108: /*@
    109:    PEPSetFromOptions - Sets PEP options from the options database.
    110:    This routine must be called before PEPSetUp() if the user is to be
    111:    allowed to set the solver type.

    113:    Collective on PEP

    115:    Input Parameters:
    116: .  pep - the polynomial eigensolver context

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

    121:    Level: beginner
    122: @*/
    123: PetscErrorCode PEPSetFromOptions(PEP pep)
    124: {
    126:   char           type[256];
    127:   PetscBool      set,flg,flg1,flg2,flg3;
    128:   PetscReal      r,t;
    129:   PetscScalar    s;
    130:   PetscInt       i,j,k;
    131:   PetscDrawLG    lg;

    135:   PEPRegisterAll();
    136:   PetscObjectOptionsBegin((PetscObject)pep);
    137:     PetscOptionsFList("-pep_type","Polynomial Eigenvalue Problem method","PEPSetType",PEPList,(char*)(((PetscObject)pep)->type_name?((PetscObject)pep)->type_name:PEPTOAR),type,256,&flg);
    138:     if (flg) {
    139:       PEPSetType(pep,type);
    140:     } else if (!((PetscObject)pep)->type_name) {
    141:       PEPSetType(pep,PEPTOAR);
    142:     }

    144:     PetscOptionsBoolGroupBegin("-pep_general","general polynomial eigenvalue problem","PEPSetProblemType",&flg);
    145:     if (flg) { PEPSetProblemType(pep,PEP_GENERAL); }
    146:     PetscOptionsBoolGroup("-pep_hermitian","hermitian polynomial eigenvalue problem","PEPSetProblemType",&flg);
    147:     if (flg) { PEPSetProblemType(pep,PEP_HERMITIAN); }
    148:     PetscOptionsBoolGroupEnd("-pep_gyroscopic","gyroscopic polynomial eigenvalue problem","PEPSetProblemType",&flg);
    149:     if (flg) { PEPSetProblemType(pep,PEP_GYROSCOPIC); }

    151:     PetscOptionsEnum("-pep_scale","Scaling strategy","PEPSetScale",PEPScaleTypes,(PetscEnum)pep->scale,(PetscEnum*)&pep->scale,NULL);

    153:     r = pep->sfactor;
    154:     PetscOptionsReal("-pep_scale_factor","Scale factor","PEPSetScale",pep->sfactor,&r,&flg1);
    155:     j = pep->sits;
    156:     PetscOptionsInt("-pep_scale_its","Number of iterations in diagonal scaling","PEPSetScale",pep->sits,&j,&flg2);
    157:     t = pep->slambda;
    158:     PetscOptionsReal("-pep_scale_lambda","Estimate of eigenvalue (modulus) for diagonal scaling","PEPSetScale",pep->slambda,&t,&flg3);
    159:     if (flg1 || flg2 || flg3) {
    160:       PEPSetScale(pep,pep->scale,r,NULL,NULL,j,t);
    161:     }

    163:     PetscOptionsEnum("-pep_extract","Extraction method","PEPSetExtract",PEPExtractTypes,(PetscEnum)pep->extract,(PetscEnum*)&pep->extract,NULL);

    165:     PetscOptionsEnum("-pep_refine","Iterative refinement method","PEPSetRefine",PEPRefineTypes,(PetscEnum)pep->refine,(PetscEnum*)&pep->refine,NULL);

    167:     i = pep->npart;
    168:     PetscOptionsInt("-pep_refine_partitions","Number of partitions of the communicator for iterative refinement","PEPSetRefine",pep->npart,&i,&flg1);
    169:     r = pep->rtol;
    170:     PetscOptionsReal("-pep_refine_tol","Tolerance for iterative refinement","PEPSetRefine",pep->rtol==PETSC_DEFAULT?SLEPC_DEFAULT_TOL/1000:pep->rtol,&r,&flg2);
    171:     j = pep->rits;
    172:     PetscOptionsInt("-pep_refine_its","Maximum number of iterations for iterative refinement","PEPSetRefine",pep->rits,&j,&flg3);
    173:     if (flg1 || flg2 || flg3) {
    174:       PEPSetRefine(pep,pep->refine,i,r,j,pep->scheme);
    175:     }

    177:     PetscOptionsEnum("-pep_refine_scheme","Scheme used for linear systems within iterative refinement","PEPSetRefine",PEPRefineSchemes,(PetscEnum)pep->scheme,(PetscEnum*)&pep->scheme,NULL);

    179:     i = pep->max_it? pep->max_it: PETSC_DEFAULT;
    180:     PetscOptionsInt("-pep_max_it","Maximum number of iterations","PEPSetTolerances",pep->max_it,&i,&flg1);
    181:     r = pep->tol;
    182:     PetscOptionsReal("-pep_tol","Tolerance","PEPSetTolerances",pep->tol==PETSC_DEFAULT?SLEPC_DEFAULT_TOL:pep->tol,&r,&flg2);
    183:     if (flg1 || flg2) {
    184:       PEPSetTolerances(pep,r,i);
    185:     }

    187:     PetscOptionsBoolGroupBegin("-pep_conv_rel","Relative error convergence test","PEPSetConvergenceTest",&flg);
    188:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_REL); }
    189:     PetscOptionsBoolGroupBegin("-pep_conv_norm","Convergence test relative to the matrix norms","PEPSetConvergenceTest",&flg);
    190:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_NORM); }
    191:     PetscOptionsBoolGroup("-pep_conv_abs","Absolute error convergence test","PEPSetConvergenceTest",&flg);
    192:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_ABS); }
    193:     PetscOptionsBoolGroupEnd("-pep_conv_user","User-defined convergence test","PEPSetConvergenceTest",&flg);
    194:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_USER); }

    196:     PetscOptionsBoolGroupBegin("-pep_stop_basic","Stop iteration if all eigenvalues converged or max_it reached","PEPSetStoppingTest",&flg);
    197:     if (flg) { PEPSetStoppingTest(pep,PEP_STOP_BASIC); }
    198:     PetscOptionsBoolGroupEnd("-pep_stop_user","User-defined stopping test","PEPSetStoppingTest",&flg);
    199:     if (flg) { PEPSetStoppingTest(pep,PEP_STOP_USER); }

    201:     i = pep->nev;
    202:     PetscOptionsInt("-pep_nev","Number of eigenvalues to compute","PEPSetDimensions",pep->nev,&i,&flg1);
    203:     j = pep->ncv? pep->ncv: PETSC_DEFAULT;
    204:     PetscOptionsInt("-pep_ncv","Number of basis vectors","PEPSetDimensions",pep->ncv,&j,&flg2);
    205:     k = pep->mpd? pep->mpd: PETSC_DEFAULT;
    206:     PetscOptionsInt("-pep_mpd","Maximum dimension of projected problem","PEPSetDimensions",pep->mpd,&k,&flg3);
    207:     if (flg1 || flg2 || flg3) {
    208:       PEPSetDimensions(pep,i,j,k);
    209:     }

    211:     PetscOptionsScalar("-pep_target","Value of the target","PEPSetTarget",pep->target,&s,&flg);
    212:     if (flg) {
    213:       PEPSetWhichEigenpairs(pep,PEP_TARGET_MAGNITUDE);
    214:       PEPSetTarget(pep,s);
    215:     }

    217:     PetscOptionsEnum("-pep_basis","Polynomial basis","PEPSetBasis",PEPBasisTypes,(PetscEnum)pep->basis,(PetscEnum*)&pep->basis,NULL);

    219:     /* -----------------------------------------------------------------------*/
    220:     /*
    221:       Cancels all monitors hardwired into code before call to PEPSetFromOptions()
    222:     */
    223:     PetscOptionsBool("-pep_monitor_cancel","Remove any hardwired monitor routines","PEPMonitorCancel",PETSC_FALSE,&flg,&set);
    224:     if (set && flg) {
    225:       PEPMonitorCancel(pep);
    226:     }
    227:     /*
    228:       Text monitors
    229:     */
    230:     PEPMonitorSetFromOptions(pep,"-pep_monitor","Monitor first unconverged approximate eigenvalue and error estimate","PEPMonitorFirst",PEPMonitorFirst,PETSC_FALSE);
    231:     PEPConvMonitorSetFromOptions(pep,"-pep_monitor_conv","Monitor approximate eigenvalues and error estimates as they converge","PEPMonitorConverged",PEPMonitorConverged);
    232:     PEPMonitorSetFromOptions(pep,"-pep_monitor_all","Monitor approximate eigenvalues and error estimates","PEPMonitorAll",PEPMonitorAll,PETSC_TRUE);
    233:     /*
    234:       Line graph monitors
    235:     */
    236:     PetscOptionsBool("-pep_monitor_lg","Monitor first unconverged approximate error estimate graphically","PEPMonitorSet",PETSC_FALSE,&flg,&set);
    237:     if (set && flg) {
    238:       PEPMonitorLGCreate(PetscObjectComm((PetscObject)pep),NULL,"Error estimates",PETSC_DECIDE,PETSC_DECIDE,300,300,&lg);
    239:       PEPMonitorSet(pep,PEPMonitorLG,lg,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
    240:     }
    241:     PetscOptionsBool("-pep_monitor_lg_all","Monitor error estimates graphically","PEPMonitorSet",PETSC_FALSE,&flg,&set);
    242:     if (set && flg) {
    243:       PEPMonitorLGCreate(PetscObjectComm((PetscObject)pep),NULL,"Error estimates",PETSC_DECIDE,PETSC_DECIDE,300,300,&lg);
    244:       PEPMonitorSet(pep,PEPMonitorLGAll,lg,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
    245:       PEPSetTrackAll(pep,PETSC_TRUE);
    246:     }
    247:   /* -----------------------------------------------------------------------*/

    249:     PetscOptionsBoolGroupBegin("-pep_largest_magnitude","compute largest eigenvalues in magnitude","PEPSetWhichEigenpairs",&flg);
    250:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_LARGEST_MAGNITUDE); }
    251:     PetscOptionsBoolGroup("-pep_smallest_magnitude","compute smallest eigenvalues in magnitude","PEPSetWhichEigenpairs",&flg);
    252:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_SMALLEST_MAGNITUDE); }
    253:     PetscOptionsBoolGroup("-pep_largest_real","compute largest real parts","PEPSetWhichEigenpairs",&flg);
    254:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_LARGEST_REAL); }
    255:     PetscOptionsBoolGroup("-pep_smallest_real","compute smallest real parts","PEPSetWhichEigenpairs",&flg);
    256:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_SMALLEST_REAL); }
    257:     PetscOptionsBoolGroup("-pep_largest_imaginary","compute largest imaginary parts","PEPSetWhichEigenpairs",&flg);
    258:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_LARGEST_IMAGINARY); }
    259:     PetscOptionsBoolGroup("-pep_smallest_imaginary","compute smallest imaginary parts","PEPSetWhichEigenpairs",&flg);
    260:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_SMALLEST_IMAGINARY); }
    261:     PetscOptionsBoolGroup("-pep_target_magnitude","compute nearest eigenvalues to target","PEPSetWhichEigenpairs",&flg);
    262:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_TARGET_MAGNITUDE); }
    263:     PetscOptionsBoolGroup("-pep_target_real","compute eigenvalues with real parts close to target","PEPSetWhichEigenpairs",&flg);
    264:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_TARGET_REAL); }
    265:     PetscOptionsBoolGroupEnd("-pep_target_imaginary","compute eigenvalues with imaginary parts close to target","PEPSetWhichEigenpairs",&flg);
    266:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_TARGET_IMAGINARY); }

    268:     PetscOptionsName("-pep_view","Print detailed information on solver used","PEPView",NULL);
    269:     PetscOptionsName("-pep_view_vectors","View computed eigenvectors","PEPVectorsView",NULL);
    270:     PetscOptionsName("-pep_view_values","View computed eigenvalues","PEPValuesView",NULL);
    271:     PetscOptionsName("-pep_converged_reason","Print reason for convergence, and number of iterations","PEPReasonView",NULL);
    272:     PetscOptionsName("-pep_error_absolute","Print absolute errors of each eigenpair","PEPErrorView",NULL);
    273:     PetscOptionsName("-pep_error_relative","Print relative errors of each eigenpair","PEPErrorView",NULL);
    274:     PetscOptionsName("-pep_error_backward","Print backward errors of each eigenpair","PEPErrorView",NULL);

    276:     if (pep->ops->setfromoptions) {
    277:       (*pep->ops->setfromoptions)(PetscOptionsObject,pep);
    278:     }
    279:     PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)pep);
    280:   PetscOptionsEnd();

    282:   if (!pep->V) { PEPGetBV(pep,&pep->V); }
    283:   BVSetFromOptions(pep->V);
    284:   if (!pep->rg) { PEPGetRG(pep,&pep->rg); }
    285:   RGSetFromOptions(pep->rg);
    286:   if (!pep->ds) { PEPGetDS(pep,&pep->ds); }
    287:   DSSetFromOptions(pep->ds);
    288:   if (!pep->st) { PEPGetST(pep,&pep->st); }
    289:   STSetFromOptions(pep->st);
    290:   if (!pep->refineksp) { PEPRefineGetKSP(pep,&pep->refineksp); }
    291:   KSPSetFromOptions(pep->refineksp);
    292:   return(0);
    293: }

    297: /*@
    298:    PEPGetTolerances - Gets the tolerance and maximum iteration count used
    299:    by the PEP convergence tests.

    301:    Not Collective

    303:    Input Parameter:
    304: .  pep - the polynomial eigensolver context

    306:    Output Parameters:
    307: +  tol - the convergence tolerance
    308: -  maxits - maximum number of iterations

    310:    Notes:
    311:    The user can specify NULL for any parameter that is not needed.

    313:    Level: intermediate

    315: .seealso: PEPSetTolerances()
    316: @*/
    317: PetscErrorCode PEPGetTolerances(PEP pep,PetscReal *tol,PetscInt *maxits)
    318: {
    321:   if (tol)    *tol    = pep->tol;
    322:   if (maxits) *maxits = pep->max_it;
    323:   return(0);
    324: }

    328: /*@
    329:    PEPSetTolerances - Sets the tolerance and maximum iteration count used
    330:    by the PEP convergence tests.

    332:    Logically Collective on PEP

    334:    Input Parameters:
    335: +  pep - the polynomial eigensolver context
    336: .  tol - the convergence tolerance
    337: -  maxits - maximum number of iterations to use

    339:    Options Database Keys:
    340: +  -pep_tol <tol> - Sets the convergence tolerance
    341: -  -pep_max_it <maxits> - Sets the maximum number of iterations allowed

    343:    Notes:
    344:    Use PETSC_DEFAULT for either argument to assign a reasonably good value.

    346:    Level: intermediate

    348: .seealso: PEPGetTolerances()
    349: @*/
    350: PetscErrorCode PEPSetTolerances(PEP pep,PetscReal tol,PetscInt maxits)
    351: {
    356:   if (tol == PETSC_DEFAULT) {
    357:     pep->tol   = PETSC_DEFAULT;
    358:     pep->state = PEP_STATE_INITIAL;
    359:   } else {
    360:     if (tol <= 0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    361:     pep->tol = tol;
    362:   }
    363:   if (maxits == PETSC_DEFAULT || maxits == PETSC_DECIDE) {
    364:     pep->max_it = 0;
    365:     pep->state  = PEP_STATE_INITIAL;
    366:   } else {
    367:     if (maxits <= 0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
    368:     pep->max_it = maxits;
    369:   }
    370:   return(0);
    371: }

    375: /*@
    376:    PEPGetDimensions - Gets the number of eigenvalues to compute
    377:    and the dimension of the subspace.

    379:    Not Collective

    381:    Input Parameter:
    382: .  pep - the polynomial eigensolver context

    384:    Output Parameters:
    385: +  nev - number of eigenvalues to compute
    386: .  ncv - the maximum dimension of the subspace to be used by the solver
    387: -  mpd - the maximum dimension allowed for the projected problem

    389:    Notes:
    390:    The user can specify NULL for any parameter that is not needed.

    392:    Level: intermediate

    394: .seealso: PEPSetDimensions()
    395: @*/
    396: PetscErrorCode PEPGetDimensions(PEP pep,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
    397: {
    400:   if (nev) *nev = pep->nev;
    401:   if (ncv) *ncv = pep->ncv;
    402:   if (mpd) *mpd = pep->mpd;
    403:   return(0);
    404: }

    408: /*@
    409:    PEPSetDimensions - Sets the number of eigenvalues to compute
    410:    and the dimension of the subspace.

    412:    Logically Collective on PEP

    414:    Input Parameters:
    415: +  pep - the polynomial eigensolver context
    416: .  nev - number of eigenvalues to compute
    417: .  ncv - the maximum dimension of the subspace to be used by the solver
    418: -  mpd - the maximum dimension allowed for the projected problem

    420:    Options Database Keys:
    421: +  -pep_nev <nev> - Sets the number of eigenvalues
    422: .  -pep_ncv <ncv> - Sets the dimension of the subspace
    423: -  -pep_mpd <mpd> - Sets the maximum projected dimension

    425:    Notes:
    426:    Use PETSC_DEFAULT for ncv and mpd to assign a reasonably good value, which is
    427:    dependent on the solution method.

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

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

    438:    Level: intermediate

    440: .seealso: PEPGetDimensions()
    441: @*/
    442: PetscErrorCode PEPSetDimensions(PEP pep,PetscInt nev,PetscInt ncv,PetscInt mpd)
    443: {
    449:   if (nev<1) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
    450:   pep->nev = nev;
    451:   if (ncv == PETSC_DECIDE || ncv == PETSC_DEFAULT) {
    452:     pep->ncv = 0;
    453:   } else {
    454:     if (ncv<1) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
    455:     pep->ncv = ncv;
    456:   }
    457:   if (mpd == PETSC_DECIDE || mpd == PETSC_DEFAULT) {
    458:     pep->mpd = 0;
    459:   } else {
    460:     if (mpd<1) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
    461:     pep->mpd = mpd;
    462:   }
    463:   pep->state = PEP_STATE_INITIAL;
    464:   return(0);
    465: }

    469: /*@
    470:    PEPSetWhichEigenpairs - Specifies which portion of the spectrum is
    471:    to be sought.

    473:    Logically Collective on PEP

    475:    Input Parameters:
    476: +  pep   - eigensolver context obtained from PEPCreate()
    477: -  which - the portion of the spectrum to be sought

    479:    Possible values:
    480:    The parameter 'which' can have one of these values

    482: +     PEP_LARGEST_MAGNITUDE - largest eigenvalues in magnitude (default)
    483: .     PEP_SMALLEST_MAGNITUDE - smallest eigenvalues in magnitude
    484: .     PEP_LARGEST_REAL - largest real parts
    485: .     PEP_SMALLEST_REAL - smallest real parts
    486: .     PEP_LARGEST_IMAGINARY - largest imaginary parts
    487: .     PEP_SMALLEST_IMAGINARY - smallest imaginary parts
    488: .     PEP_TARGET_MAGNITUDE - eigenvalues closest to the target (in magnitude)
    489: .     PEP_TARGET_REAL - eigenvalues with real part closest to target
    490: .     PEP_TARGET_IMAGINARY - eigenvalues with imaginary part closest to target
    491: -     PEP_WHICH_USER - user defined ordering set with PEPSetEigenvalueComparison()

    493:    Options Database Keys:
    494: +   -pep_largest_magnitude - Sets largest eigenvalues in magnitude
    495: .   -pep_smallest_magnitude - Sets smallest eigenvalues in magnitude
    496: .   -pep_largest_real - Sets largest real parts
    497: .   -pep_smallest_real - Sets smallest real parts
    498: .   -pep_largest_imaginary - Sets largest imaginary parts
    499: .   -pep_smallest_imaginary - Sets smallest imaginary parts
    500: .   -pep_target_magnitude - Sets eigenvalues closest to target
    501: .   -pep_target_real - Sets real parts closest to target
    502: -   -pep_target_imaginary - Sets imaginary parts closest to target

    504:    Notes:
    505:    Not all eigensolvers implemented in PEP account for all the possible values
    506:    stated above. If SLEPc is compiled for real numbers PEP_LARGEST_IMAGINARY
    507:    and PEP_SMALLEST_IMAGINARY use the absolute value of the imaginary part
    508:    for eigenvalue selection.

    510:    The target is a scalar value provided with PEPSetTarget().

    512:    The criterion PEP_TARGET_IMAGINARY is available only in case PETSc and
    513:    SLEPc have been built with complex scalars.

    515:    Level: intermediate

    517: .seealso: PEPGetWhichEigenpairs(), PEPSetTarget(), PEPSetEigenvalueComparison(), PEPWhich
    518: @*/
    519: PetscErrorCode PEPSetWhichEigenpairs(PEP pep,PEPWhich which)
    520: {
    524:   switch (which) {
    525:     case PEP_LARGEST_MAGNITUDE:
    526:     case PEP_SMALLEST_MAGNITUDE:
    527:     case PEP_LARGEST_REAL:
    528:     case PEP_SMALLEST_REAL:
    529:     case PEP_LARGEST_IMAGINARY:
    530:     case PEP_SMALLEST_IMAGINARY:
    531:     case PEP_TARGET_MAGNITUDE:
    532:     case PEP_TARGET_REAL:
    533: #if defined(PETSC_USE_COMPLEX)
    534:     case PEP_TARGET_IMAGINARY:
    535: #endif
    536:     case PEP_WHICH_USER:
    537:       if (pep->which != which) {
    538:         pep->state = PEP_STATE_INITIAL;
    539:         pep->which = which;
    540:       }
    541:       break;
    542:     default:
    543:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'which' value");
    544:   }
    545:   return(0);
    546: }

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

    554:     Not Collective

    556:     Input Parameter:
    557: .   pep - eigensolver context obtained from PEPCreate()

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

    562:     Notes:
    563:     See PEPSetWhichEigenpairs() for possible values of 'which'.

    565:     Level: intermediate

    567: .seealso: PEPSetWhichEigenpairs(), PEPWhich
    568: @*/
    569: PetscErrorCode PEPGetWhichEigenpairs(PEP pep,PEPWhich *which)
    570: {
    574:   *which = pep->which;
    575:   return(0);
    576: }

    580: /*@C
    581:    PEPSetEigenvalueComparison - Specifies the eigenvalue comparison function
    582:    when PEPSetWhichEigenpairs() is set to PEP_WHICH_USER.

    584:    Logically Collective on PEP

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

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

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

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

    607:    Level: advanced

    609: .seealso: PEPSetWhichEigenpairs(), PEPWhich
    610: @*/
    611: PetscErrorCode PEPSetEigenvalueComparison(PEP pep,PetscErrorCode (*func)(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*),void* ctx)
    612: {
    615:   pep->sc->comparison    = func;
    616:   pep->sc->comparisonctx = ctx;
    617:   pep->which             = PEP_WHICH_USER;
    618:   return(0);
    619: }

    623: /*@
    624:    PEPSetProblemType - Specifies the type of the polynomial eigenvalue problem.

    626:    Logically Collective on PEP

    628:    Input Parameters:
    629: +  pep  - the polynomial eigensolver context
    630: -  type - a known type of polynomial eigenvalue problem

    632:    Options Database Keys:
    633: +  -pep_general - general problem with no particular structure
    634: .  -pep_hermitian - problem whose coefficient matrices are Hermitian
    635: -  -pep_gyroscopic - problem with Hamiltonian structure

    637:    Notes:
    638:    Allowed values for the problem type are: general (PEP_GENERAL), Hermitian
    639:    (PEP_HERMITIAN), and gyroscopic (PEP_GYROSCOPIC).

    641:    This function is used to instruct SLEPc to exploit certain structure in
    642:    the polynomial eigenproblem. By default, no particular structure is assumed.

    644:    If the problem matrices are Hermitian (symmetric in the real case) or
    645:    Hermitian/skew-Hermitian then the solver can exploit this fact to perform
    646:    less operations or provide better stability.

    648:    Level: intermediate

    650: .seealso: PEPSetOperators(), PEPSetType(), PEPGetProblemType(), PEPProblemType
    651: @*/
    652: PetscErrorCode PEPSetProblemType(PEP pep,PEPProblemType type)
    653: {
    657:   if (type!=PEP_GENERAL && type!=PEP_HERMITIAN && type!=PEP_GYROSCOPIC) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_WRONG,"Unknown eigenvalue problem type");
    658:   if (type != pep->problem_type) {
    659:     pep->problem_type = type;
    660:     pep->state = PEP_STATE_INITIAL;
    661:   }
    662:   return(0);
    663: }

    667: /*@
    668:    PEPGetProblemType - Gets the problem type from the PEP object.

    670:    Not Collective

    672:    Input Parameter:
    673: .  pep - the polynomial eigensolver context

    675:    Output Parameter:
    676: .  type - name of PEP problem type

    678:    Level: intermediate

    680: .seealso: PEPSetProblemType(), PEPProblemType
    681: @*/
    682: PetscErrorCode PEPGetProblemType(PEP pep,PEPProblemType *type)
    683: {
    687:   *type = pep->problem_type;
    688:   return(0);
    689: }

    693: /*@
    694:    PEPSetBasis - Specifies the type of polynomial basis used to describe the
    695:    polynomial eigenvalue problem.

    697:    Logically Collective on PEP

    699:    Input Parameters:
    700: +  pep   - the polynomial eigensolver context
    701: -  basis - the type of polynomial basis

    703:    Options Database Key:
    704: .  -pep_basis <basis> - Select the basis type

    706:    Notes:
    707:    By default, the coefficient matrices passed via PEPSetOperators() are
    708:    expressed in the monomial basis, i.e.
    709:    P(lambda) = A_0 + lambda*A_1 + lambda^2*A_2 + ... + lambda^d*A_d.
    710:    Other polynomial bases may have better numerical behaviour, but the user
    711:    must then pass the coefficient matrices accordingly.

    713:    Level: intermediate

    715: .seealso: PEPSetOperators(), PEPGetBasis(), PEPBasis
    716: @*/
    717: PetscErrorCode PEPSetBasis(PEP pep,PEPBasis basis)
    718: {
    722:   pep->basis = basis;
    723:   return(0);
    724: }

    728: /*@
    729:    PEPGetBasis - Gets the type of polynomial basis from the PEP object.

    731:    Not Collective

    733:    Input Parameter:
    734: .  pep - the polynomial eigensolver context

    736:    Output Parameter:
    737: .  basis - the polynomial basis

    739:    Level: intermediate

    741: .seealso: PEPSetBasis(), PEPBasis
    742: @*/
    743: PetscErrorCode PEPGetBasis(PEP pep,PEPBasis *basis)
    744: {
    748:   *basis = pep->basis;
    749:   return(0);
    750: }

    754: /*@
    755:    PEPSetTrackAll - Specifies if the solver must compute the residual of all
    756:    approximate eigenpairs or not.

    758:    Logically Collective on PEP

    760:    Input Parameters:
    761: +  pep      - the eigensolver context
    762: -  trackall - whether compute all residuals or not

    764:    Notes:
    765:    If the user sets trackall=PETSC_TRUE then the solver explicitly computes
    766:    the residual for each eigenpair approximation. Computing the residual is
    767:    usually an expensive operation and solvers commonly compute the associated
    768:    residual to the first unconverged eigenpair.
    769:    The options '-pep_monitor_all' and '-pep_monitor_lg_all' automatically
    770:    activate this option.

    772:    Level: developer

    774: .seealso: PEPGetTrackAll()
    775: @*/
    776: PetscErrorCode PEPSetTrackAll(PEP pep,PetscBool trackall)
    777: {
    781:   pep->trackall = trackall;
    782:   return(0);
    783: }

    787: /*@
    788:    PEPGetTrackAll - Returns the flag indicating whether all residual norms must
    789:    be computed or not.

    791:    Not Collective

    793:    Input Parameter:
    794: .  pep - the eigensolver context

    796:    Output Parameter:
    797: .  trackall - the returned flag

    799:    Level: developer

    801: .seealso: PEPSetTrackAll()
    802: @*/
    803: PetscErrorCode PEPGetTrackAll(PEP pep,PetscBool *trackall)
    804: {
    808:   *trackall = pep->trackall;
    809:   return(0);
    810: }

    814: /*@C
    815:    PEPSetConvergenceTestFunction - Sets a function to compute the error estimate
    816:    used in the convergence test.

    818:    Logically Collective on PEP

    820:    Input Parameters:
    821: +  pep     - eigensolver context obtained from PEPCreate()
    822: .  func    - a pointer to the convergence test function
    823: .  ctx     - context for private data for the convergence routine (may be null)
    824: -  destroy - a routine for destroying the context (may be null)

    826:    Calling Sequence of func:
    827: $   func(PEP pep,PetscScalar eigr,PetscScalar eigi,PetscReal res,PetscReal *errest,void *ctx)

    829: +   pep    - eigensolver context obtained from PEPCreate()
    830: .   eigr   - real part of the eigenvalue
    831: .   eigi   - imaginary part of the eigenvalue
    832: .   res    - residual norm associated to the eigenpair
    833: .   errest - (output) computed error estimate
    834: -   ctx    - optional context, as set by PEPSetConvergenceTestFunction()

    836:    Note:
    837:    If the error estimate returned by the convergence test function is less than
    838:    the tolerance, then the eigenvalue is accepted as converged.

    840:    Level: advanced

    842: .seealso: PEPSetConvergenceTest(), PEPSetTolerances()
    843: @*/
    844: PetscErrorCode PEPSetConvergenceTestFunction(PEP pep,PetscErrorCode (*func)(PEP,PetscScalar,PetscScalar,PetscReal,PetscReal*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    845: {

    850:   if (pep->convergeddestroy) {
    851:     (*pep->convergeddestroy)(pep->convergedctx);
    852:   }
    853:   pep->converged        = func;
    854:   pep->convergeddestroy = destroy;
    855:   pep->convergedctx     = ctx;
    856:   if (func == PEPConvergedRelative) pep->conv = PEP_CONV_REL;
    857:   else if (func == PEPConvergedNorm) pep->conv = PEP_CONV_NORM;
    858:   else if (func == PEPConvergedAbsolute) pep->conv = PEP_CONV_ABS;
    859:   else pep->conv = PEP_CONV_USER;
    860:   return(0);
    861: }

    865: /*@
    866:    PEPSetConvergenceTest - Specifies how to compute the error estimate
    867:    used in the convergence test.

    869:    Logically Collective on PEP

    871:    Input Parameters:
    872: +  pep  - eigensolver context obtained from PEPCreate()
    873: -  conv - the type of convergence test

    875:    Options Database Keys:
    876: +  -pep_conv_abs    - Sets the absolute convergence test
    877: .  -pep_conv_rel    - Sets the convergence test relative to the eigenvalue
    878: .  -pep_conv_norm   - Sets the convergence test relative to the matrix norms
    879: -  -pep_conv_user   - Selects the user-defined convergence test

    881:    Note:
    882:    The parameter 'conv' can have one of these values
    883: +     PEP_CONV_ABS    - absolute error ||r||
    884: .     PEP_CONV_REL    - error relative to the eigenvalue l, ||r||/|l|
    885: .     PEP_CONV_NORM   - error relative matrix norms, ||r||/sum_i(l^i*||A_i||)
    886: -     PEP_CONV_USER   - function set by PEPSetConvergenceTestFunction()

    888:    Level: intermediate

    890: .seealso: PEPGetConvergenceTest(), PEPSetConvergenceTestFunction(), PEPSetStoppingTest(), PEPConv
    891: @*/
    892: PetscErrorCode PEPSetConvergenceTest(PEP pep,PEPConv conv)
    893: {
    897:   switch (conv) {
    898:     case PEP_CONV_ABS:    pep->converged = PEPConvergedAbsolute; break;
    899:     case PEP_CONV_REL:    pep->converged = PEPConvergedRelative; break;
    900:     case PEP_CONV_NORM:   pep->converged = PEPConvergedNorm; break;
    901:     case PEP_CONV_USER: break;
    902:     default:
    903:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'conv' value");
    904:   }
    905:   pep->conv = conv;
    906:   return(0);
    907: }

    911: /*@
    912:    PEPGetConvergenceTest - Gets the method used to compute the error estimate
    913:    used in the convergence test.

    915:    Not Collective

    917:    Input Parameters:
    918: .  pep   - eigensolver context obtained from PEPCreate()

    920:    Output Parameters:
    921: .  conv  - the type of convergence test

    923:    Level: intermediate

    925: .seealso: PEPSetConvergenceTest(), PEPConv
    926: @*/
    927: PetscErrorCode PEPGetConvergenceTest(PEP pep,PEPConv *conv)
    928: {
    932:   *conv = pep->conv;
    933:   return(0);
    934: }

    938: /*@C
    939:    PEPSetStoppingTestFunction - Sets a function to decide when to stop the outer
    940:    iteration of the eigensolver.

    942:    Logically Collective on PEP

    944:    Input Parameters:
    945: +  pep     - eigensolver context obtained from PEPCreate()
    946: .  func    - pointer to the stopping test function
    947: .  ctx     - context for private data for the stopping routine (may be null)
    948: -  destroy - a routine for destroying the context (may be null)

    950:    Calling Sequence of func:
    951: $   func(PEP pep,PetscInt its,PetscInt max_it,PetscInt nconv,PetscInt nev,PEPConvergedReason *reason,void *ctx)

    953: +   pep    - eigensolver context obtained from PEPCreate()
    954: .   its    - current number of iterations
    955: .   max_it - maximum number of iterations
    956: .   nconv  - number of currently converged eigenpairs
    957: .   nev    - number of requested eigenpairs
    958: .   reason - (output) result of the stopping test
    959: -   ctx    - optional context, as set by PEPSetStoppingTestFunction()

    961:    Note:
    962:    Normal usage is to first call the default routine PEPStoppingBasic() and then
    963:    set reason to PEP_CONVERGED_USER if some user-defined conditions have been
    964:    met. To let the eigensolver continue iterating, the result must be left as
    965:    PEP_CONVERGED_ITERATING.

    967:    Level: advanced

    969: .seealso: PEPSetStoppingTest(), PEPStoppingBasic()
    970: @*/
    971: PetscErrorCode PEPSetStoppingTestFunction(PEP pep,PetscErrorCode (*func)(PEP,PetscInt,PetscInt,PetscInt,PetscInt,PEPConvergedReason*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    972: {

    977:   if (pep->stoppingdestroy) {
    978:     (*pep->stoppingdestroy)(pep->stoppingctx);
    979:   }
    980:   pep->stopping        = func;
    981:   pep->stoppingdestroy = destroy;
    982:   pep->stoppingctx     = ctx;
    983:   if (func == PEPStoppingBasic) pep->stop = PEP_STOP_BASIC;
    984:   else pep->stop = PEP_STOP_USER;
    985:   return(0);
    986: }

    990: /*@
    991:    PEPSetStoppingTest - Specifies how to decide the termination of the outer
    992:    loop of the eigensolver.

    994:    Logically Collective on PEP

    996:    Input Parameters:
    997: +  pep  - eigensolver context obtained from PEPCreate()
    998: -  stop - the type of stopping test

    1000:    Options Database Keys:
    1001: +  -pep_stop_basic - Sets the default stopping test
    1002: -  -pep_stop_user  - Selects the user-defined stopping test

    1004:    Note:
    1005:    The parameter 'stop' can have one of these values
    1006: +     PEP_STOP_BASIC - default stopping test
    1007: -     PEP_STOP_USER  - function set by PEPSetStoppingTestFunction()

    1009:    Level: advanced

    1011: .seealso: PEPGetStoppingTest(), PEPSetStoppingTestFunction(), PEPSetConvergenceTest(), PEPStop
    1012: @*/
    1013: PetscErrorCode PEPSetStoppingTest(PEP pep,PEPStop stop)
    1014: {
    1018:   switch (stop) {
    1019:     case PEP_STOP_BASIC: pep->stopping = PEPStoppingBasic; break;
    1020:     case PEP_STOP_USER:  break;
    1021:     default:
    1022:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'stop' value");
    1023:   }
    1024:   pep->stop = stop;
    1025:   return(0);
    1026: }

    1030: /*@
    1031:    PEPGetStoppingTest - Gets the method used to decide the termination of the outer
    1032:    loop of the eigensolver.

    1034:    Not Collective

    1036:    Input Parameters:
    1037: .  pep   - eigensolver context obtained from PEPCreate()

    1039:    Output Parameters:
    1040: .  stop  - the type of stopping test

    1042:    Level: advanced

    1044: .seealso: PEPSetStoppingTest(), PEPStop
    1045: @*/
    1046: PetscErrorCode PEPGetStoppingTest(PEP pep,PEPStop *stop)
    1047: {
    1051:   *stop = pep->stop;
    1052:   return(0);
    1053: }

    1057: /*@
    1058:    PEPSetScale - Specifies the scaling strategy to be used.

    1060:    Logically Collective on PEP

    1062:    Input Parameters:
    1063: +  pep    - the eigensolver context
    1064: .  scale  - scaling strategy
    1065: .  alpha  - the scaling factor used in the scalar strategy
    1066: .  Dl     - the left diagonal matrix of the diagonal scaling algorithm
    1067: .  Dr     - the right diagonal matrix of the diagonal scaling algorithm
    1068: .  its    - number of iterations of the diagonal scaling algorithm
    1069: -  lambda - approximation to wanted eigenvalues (modulus)

    1071:    Options Database Keys:
    1072: +  -pep_scale <type> - scaling type, one of <none,scalar,diagonal,both>
    1073: .  -pep_scale_factor <alpha> - the scaling factor
    1074: .  -pep_scale_its <its> - number of iterations
    1075: -  -pep_scale_lambda <lambda> - approximation to eigenvalues

    1077:    Notes:
    1078:    There are two non-exclusive scaling strategies: scalar and diagonal.

    1080:    In the scalar strategy, scaling is applied to the eigenvalue, that is,
    1081:    mu = lambda/alpha is the new eigenvalue and all matrices are scaled
    1082:    accordingly. After solving the scaled problem, the original lambda is
    1083:    recovered. Parameter 'alpha' must be positive. Use PETSC_DECIDE to let
    1084:    the solver compute a reasonable scaling factor.

    1086:    In the diagonal strategy, the solver works implicitly with matrix Dl*A*Dr,
    1087:    where Dl and Dr are appropriate diagonal matrices. This improves the accuracy
    1088:    of the computed results in some cases. The user may provide the Dr and Dl
    1089:    matrices represented as Vec objects storing diagonal elements. If not
    1090:    provided, these matrices are computed internally. This option requires
    1091:    that the polynomial coefficient matrices are of MATAIJ type.
    1092:    The parameter 'its' is the number of iterations performed by the method.
    1093:    Parameter 'lambda' must be positive. Use PETSC_DECIDE or set lambda = 1.0 if
    1094:    no information about eigenvalues is available.

    1096:    Level: intermediate

    1098: .seealso: PEPGetScale()
    1099: @*/
    1100: PetscErrorCode PEPSetScale(PEP pep,PEPScale scale,PetscReal alpha,Vec Dl,Vec Dr,PetscInt its,PetscReal lambda)
    1101: {

    1107:   pep->scale = scale;
    1108:   if (scale==PEP_SCALE_SCALAR || scale==PEP_SCALE_BOTH) {
    1110:     if (alpha == PETSC_DEFAULT || alpha == PETSC_DECIDE) {
    1111:       pep->sfactor = 0.0;
    1112:       pep->sfactor_set = PETSC_FALSE;
    1113:     } else {
    1114:       if (alpha<=0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of alpha. Must be > 0");
    1115:       pep->sfactor = alpha;
    1116:       pep->sfactor_set = PETSC_TRUE;
    1117:     }
    1118:   }
    1119:   if (scale==PEP_SCALE_DIAGONAL || scale==PEP_SCALE_BOTH) {
    1120:     if (Dl) {
    1123:       PetscObjectReference((PetscObject)Dl);
    1124:       VecDestroy(&pep->Dl);
    1125:       pep->Dl = Dl;
    1126:     }
    1127:     if (Dr) {
    1130:       PetscObjectReference((PetscObject)Dr);
    1131:       VecDestroy(&pep->Dr);
    1132:       pep->Dr = Dr;
    1133:     }
    1136:     if (its==PETSC_DECIDE || its==PETSC_DEFAULT) pep->sits = 5;
    1137:     else pep->sits = its;
    1138:     if (lambda==PETSC_DECIDE || lambda==PETSC_DEFAULT) pep->slambda = 1.0;
    1139:     else if (lambda<=0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of lambda. Must be > 0");
    1140:     else pep->slambda = lambda;
    1141:   }
    1142:   pep->state = PEP_STATE_INITIAL;
    1143:   return(0);
    1144: }

    1148: /*@
    1149:    PEPGetScale - Gets the scaling strategy used by the PEP object, and the
    1150:    associated parameters.

    1152:    Not Collectiv, but vectors are shared by all processors that share the PEP

    1154:    Input Parameter:
    1155: .  pep - the eigensolver context

    1157:    Output Parameters:
    1158: +  scale  - scaling strategy
    1159: .  alpha  - the scaling factor used in the scalar strategy
    1160: .  Dl     - the left diagonal matrix of the diagonal scaling algorithm
    1161: .  Dr     - the right diagonal matrix of the diagonal scaling algorithm
    1162: .  its    - number of iterations of the diagonal scaling algorithm
    1163: -  lambda - approximation to wanted eigenvalues (modulus)

    1165:    Level: intermediate

    1167:    Note:
    1168:    The user can specify NULL for any parameter that is not needed.

    1170:    If Dl or Dr were not set by the user, then the ones computed internally are
    1171:    returned (or a null pointer if called before PEPSetUp).

    1173: .seealso: PEPSetScale(), PEPSetUp()
    1174: @*/
    1175: PetscErrorCode PEPGetScale(PEP pep,PEPScale *scale,PetscReal *alpha,Vec *Dl,Vec *Dr,PetscInt *its,PetscReal *lambda)
    1176: {
    1179:   if (scale)  *scale  = pep->scale;
    1180:   if (alpha)  *alpha  = pep->sfactor;
    1181:   if (Dl)     *Dl     = pep->Dl;
    1182:   if (Dr)     *Dr     = pep->Dr;
    1183:   if (its)    *its    = pep->sits;
    1184:   if (lambda) *lambda = pep->slambda;
    1185:   return(0);
    1186: }

    1190: /*@
    1191:    PEPSetExtract - Specifies the extraction strategy to be used.

    1193:    Logically Collective on PEP

    1195:    Input Parameters:
    1196: +  pep     - the eigensolver context
    1197: -  extract - extraction strategy

    1199:    Options Database Keys:
    1200: .  -pep_extract <type> - extraction type, one of <none,norm,residual,structured>

    1202:    Level: intermediate

    1204: .seealso: PEPGetExtract()
    1205: @*/
    1206: PetscErrorCode PEPSetExtract(PEP pep,PEPExtract extract)
    1207: {
    1211:   pep->extract = extract;
    1212:   return(0);
    1213: }

    1217: /*@
    1218:    PEPGetExtract - Gets the extraction strategy used by the PEP object.

    1220:    Not Collective

    1222:    Input Parameter:
    1223: .  pep - the eigensolver context

    1225:    Output Parameter:
    1226: .  extract - extraction strategy

    1228:    Level: intermediate

    1230: .seealso: PEPSetExtract()
    1231: @*/
    1232: PetscErrorCode PEPGetExtract(PEP pep,PEPExtract *extract)
    1233: {
    1236:   if (extract) *extract = pep->extract;
    1237:   return(0);
    1238: }

    1242: /*@
    1243:    PEPSetRefine - Specifies the refinement type (and options) to be used
    1244:    after the solve.

    1246:    Logically Collective on PEP

    1248:    Input Parameters:
    1249: +  pep    - the polynomial eigensolver context
    1250: .  refine - refinement type
    1251: .  npart  - number of partitions of the communicator
    1252: .  tol    - the convergence tolerance
    1253: .  its    - maximum number of refinement iterations
    1254: -  scheme - which scheme to be used for solving the involved linear systems

    1256:    Options Database Keys:
    1257: +  -pep_refine <type> - refinement type, one of <none,simple,multiple>
    1258: .  -pep_refine_partitions <n> - the number of partitions
    1259: .  -pep_refine_tol <tol> - the tolerance
    1260: .  -pep_refine_its <its> - number of iterations
    1261: -  -pep_refine_scheme - to set the scheme for the linear solves

    1263:    Notes:
    1264:    By default, iterative refinement is disabled, since it may be very
    1265:    costly. There are two possible refinement strategies: simple and multiple.
    1266:    The simple approach performs iterative refinement on each of the
    1267:    converged eigenpairs individually, whereas the multiple strategy works
    1268:    with the invariant pair as a whole, refining all eigenpairs simultaneously.
    1269:    The latter may be required for the case of multiple eigenvalues.

    1271:    In some cases, especially when using direct solvers within the
    1272:    iterative refinement method, it may be helpful for improved scalability
    1273:    to split the communicator in several partitions. The npart parameter
    1274:    indicates how many partitions to use (defaults to 1).

    1276:    The tol and its parameters specify the stopping criterion. In the simple
    1277:    method, refinement continues until the residual of each eigenpair is
    1278:    below the tolerance (tol defaults to the PEP tol, but may be set to a
    1279:    different value). In contrast, the multiple method simply performs its
    1280:    refinement iterations (just one by default).

    1282:    The scheme argument is used to change the way in which linear systems are
    1283:    solved. Possible choices are: explicit, mixed block elimination (MBE),
    1284:    and Schur complement.

    1286:    Level: intermediate

    1288: .seealso: PEPGetRefine()
    1289: @*/
    1290: PetscErrorCode PEPSetRefine(PEP pep,PEPRefine refine,PetscInt npart,PetscReal tol,PetscInt its,PEPRefineScheme scheme)
    1291: {
    1293:   PetscMPIInt    size;

    1302:   pep->refine = refine;
    1303:   if (refine) {  /* process parameters only if not REFINE_NONE */
    1304:     if (npart!=pep->npart) {
    1305:       PetscSubcommDestroy(&pep->refinesubc);
    1306:       KSPDestroy(&pep->refineksp);
    1307:     }
    1308:     if (npart == PETSC_DEFAULT || npart == PETSC_DECIDE) {
    1309:       pep->npart = 1;
    1310:     } else {
    1311:       MPI_Comm_size(PetscObjectComm((PetscObject)pep),&size);
    1312:       if (npart<1 || npart>size) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of npart");
    1313:       pep->npart = npart;
    1314:     }
    1315:     if (tol == PETSC_DEFAULT || tol == PETSC_DECIDE) {
    1316:       pep->rtol = PetscMax(pep->tol/1000,PETSC_MACHINE_EPSILON);
    1317:     } else {
    1318:       if (tol<=0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    1319:       pep->rtol = tol;
    1320:     }
    1321:     if (its==PETSC_DECIDE || its==PETSC_DEFAULT) {
    1322:       pep->rits = PETSC_DEFAULT;
    1323:     } else {
    1324:       if (its<0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be >= 0");
    1325:       pep->rits = its;
    1326:     }
    1327:     pep->scheme = scheme;
    1328:   }
    1329:   pep->state = PEP_STATE_INITIAL;
    1330:   return(0);
    1331: }

    1335: /*@
    1336:    PEPGetRefine - Gets the refinement strategy used by the PEP object, and the
    1337:    associated parameters.

    1339:    Not Collective

    1341:    Input Parameter:
    1342: .  pep - the polynomial eigensolver context

    1344:    Output Parameters:
    1345: +  refine - refinement type
    1346: .  npart  - number of partitions of the communicator
    1347: .  tol    - the convergence tolerance
    1348: .  its    - maximum number of refinement iterations
    1349: -  scheme - the scheme used for solving linear systems

    1351:    Level: intermediate

    1353:    Note:
    1354:    The user can specify NULL for any parameter that is not needed.

    1356: .seealso: PEPSetRefine()
    1357: @*/
    1358: PetscErrorCode PEPGetRefine(PEP pep,PEPRefine *refine,PetscInt *npart,PetscReal *tol,PetscInt *its,PEPRefineScheme *scheme)
    1359: {
    1362:   if (refine) *refine = pep->refine;
    1363:   if (npart)  *npart  = pep->npart;
    1364:   if (tol)    *tol    = pep->rtol;
    1365:   if (its)    *its    = pep->rits;
    1366:   if (scheme) *scheme = pep->scheme;
    1367:   return(0);
    1368: }

    1372: /*@C
    1373:    PEPSetOptionsPrefix - Sets the prefix used for searching for all
    1374:    PEP options in the database.

    1376:    Logically Collective on PEP

    1378:    Input Parameters:
    1379: +  pep - the polynomial eigensolver context
    1380: -  prefix - the prefix string to prepend to all PEP option requests

    1382:    Notes:
    1383:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1384:    The first character of all runtime options is AUTOMATICALLY the
    1385:    hyphen.

    1387:    For example, to distinguish between the runtime options for two
    1388:    different PEP contexts, one could call
    1389: .vb
    1390:       PEPSetOptionsPrefix(pep1,"qeig1_")
    1391:       PEPSetOptionsPrefix(pep2,"qeig2_")
    1392: .ve

    1394:    Level: advanced

    1396: .seealso: PEPAppendOptionsPrefix(), PEPGetOptionsPrefix()
    1397: @*/
    1398: PetscErrorCode PEPSetOptionsPrefix(PEP pep,const char *prefix)
    1399: {

    1404:   if (!pep->st) { PEPGetST(pep,&pep->st); }
    1405:   STSetOptionsPrefix(pep->st,prefix);
    1406:   if (!pep->V) { PEPGetBV(pep,&pep->V); }
    1407:   BVSetOptionsPrefix(pep->V,prefix);
    1408:   if (!pep->ds) { PEPGetDS(pep,&pep->ds); }
    1409:   DSSetOptionsPrefix(pep->ds,prefix);
    1410:   if (!pep->rg) { PEPGetRG(pep,&pep->rg); }
    1411:   RGSetOptionsPrefix(pep->rg,prefix);
    1412:   PetscObjectSetOptionsPrefix((PetscObject)pep,prefix);
    1413:   return(0);
    1414: }

    1418: /*@C
    1419:    PEPAppendOptionsPrefix - Appends to the prefix used for searching for all
    1420:    PEP options in the database.

    1422:    Logically Collective on PEP

    1424:    Input Parameters:
    1425: +  pep - the polynomial eigensolver context
    1426: -  prefix - the prefix string to prepend to all PEP option requests

    1428:    Notes:
    1429:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1430:    The first character of all runtime options is AUTOMATICALLY the hyphen.

    1432:    Level: advanced

    1434: .seealso: PEPSetOptionsPrefix(), PEPGetOptionsPrefix()
    1435: @*/
    1436: PetscErrorCode PEPAppendOptionsPrefix(PEP pep,const char *prefix)
    1437: {
    1439:   PetscBool      flg;
    1440:   EPS            eps;

    1444:   if (!pep->st) { PEPGetST(pep,&pep->st); }
    1445:   STAppendOptionsPrefix(pep->st,prefix);
    1446:   if (!pep->V) { PEPGetBV(pep,&pep->V); }
    1447:   BVSetOptionsPrefix(pep->V,prefix);
    1448:   if (!pep->ds) { PEPGetDS(pep,&pep->ds); }
    1449:   DSSetOptionsPrefix(pep->ds,prefix);
    1450:   if (!pep->rg) { PEPGetRG(pep,&pep->rg); }
    1451:   RGSetOptionsPrefix(pep->rg,prefix);
    1452:   PetscObjectAppendOptionsPrefix((PetscObject)pep,prefix);
    1453:   PetscObjectTypeCompare((PetscObject)pep,PEPLINEAR,&flg);
    1454:   if (flg) {
    1455:     PEPLinearGetEPS(pep,&eps);
    1456:     EPSSetOptionsPrefix(eps,((PetscObject)pep)->prefix);
    1457:     EPSAppendOptionsPrefix(eps,"pep_");
    1458:   }
    1459:   return(0);
    1460: }

    1464: /*@C
    1465:    PEPGetOptionsPrefix - Gets the prefix used for searching for all
    1466:    PEP options in the database.

    1468:    Not Collective

    1470:    Input Parameters:
    1471: .  pep - the polynomial eigensolver context

    1473:    Output Parameters:
    1474: .  prefix - pointer to the prefix string used is returned

    1476:    Note:
    1477:    On the Fortran side, the user should pass in a string 'prefix' of
    1478:    sufficient length to hold the prefix.

    1480:    Level: advanced

    1482: .seealso: PEPSetOptionsPrefix(), PEPAppendOptionsPrefix()
    1483: @*/
    1484: PetscErrorCode PEPGetOptionsPrefix(PEP pep,const char *prefix[])
    1485: {

    1491:   PetscObjectGetOptionsPrefix((PetscObject)pep,prefix);
    1492:   return(0);
    1493: }