Date: 2021-09-20T09:44:04+00:00

Actual source code: pepopts.c
slepc-3.15.2 2021-09-20
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2021, 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:    PEP routines related to options that can be set via the command-line
     12:    or procedurally
     13: */

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

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

     22:    Collective on pep

     24:    Input Parameters:
     25: +  pep      - the polynomial eigensolver context
     26: .  opt      - the command line option for this monitor
     27: .  name     - the monitor type one is seeking
     28: .  ctx      - an optional user context for the monitor, or NULL
     29: -  trackall - whether this monitor tracks all eigenvalues or not

     31:    Level: developer

     33: .seealso: PEPMonitorSet(), PEPSetTrackAll()
     34: @*/
     35: PetscErrorCode PEPMonitorSetFromOptions(PEP pep,const char opt[],const char name[],void *ctx,PetscBool trackall)
     36: {
     37:   PetscErrorCode       (*mfunc)(PEP,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,void*);
     38:   PetscErrorCode       (*cfunc)(PetscViewer,PetscViewerFormat,void*,PetscViewerAndFormat**);
     39:   PetscErrorCode       (*dfunc)(PetscViewerAndFormat**);
     40:   PetscViewerAndFormat *vf;
     41:   PetscViewer          viewer;
     42:   PetscViewerFormat    format;
     43:   PetscViewerType      vtype;
     44:   char                 key[PETSC_MAX_PATH_LEN];
     45:   PetscBool            flg;
     46:   PetscErrorCode       ierr;

     49:   PetscOptionsGetViewer(PetscObjectComm((PetscObject)pep),((PetscObject)pep)->options,((PetscObject)pep)->prefix,opt,&viewer,&format,&flg);
     50:   if (!flg) return(0);

     52:   PetscViewerGetType(viewer,&vtype);
     53:   SlepcMonitorMakeKey_Internal(name,vtype,format,key);
     54:   PetscFunctionListFind(PEPMonitorList,key,&mfunc);
     55:   PetscFunctionListFind(PEPMonitorCreateList,key,&cfunc);
     56:   PetscFunctionListFind(PEPMonitorDestroyList,key,&dfunc);
     57:   if (!cfunc) cfunc = PetscViewerAndFormatCreate_Internal;
     58:   if (!dfunc) dfunc = PetscViewerAndFormatDestroy;

     60:   (*cfunc)(viewer,format,ctx,&vf);
     61:   PetscObjectDereference((PetscObject)viewer);
     62:   PEPMonitorSet(pep,mfunc,vf,(PetscErrorCode(*)(void **))dfunc);
     63:   if (trackall) {
     64:     PEPSetTrackAll(pep,PETSC_TRUE);
     65:   }
     66:   return(0);
     67: }

     69: /*@
     70:    PEPSetFromOptions - Sets PEP options from the options database.
     71:    This routine must be called before PEPSetUp() if the user is to be
     72:    allowed to set the solver type.

     74:    Collective on pep

     76:    Input Parameters:
     77: .  pep - the polynomial eigensolver context

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

     82:    Level: beginner
     83: @*/
     84: PetscErrorCode PEPSetFromOptions(PEP pep)
     85: {
     86:   PetscErrorCode  ierr;
     87:   char            type[256];
     88:   PetscBool       set,flg,flg1,flg2,flg3,flg4,flg5;
     89:   PetscReal       r,t,array[2]={0,0};
     90:   PetscScalar     s;
     91:   PetscInt        i,j,k;
     92:   PEPScale        scale;
     93:   PEPRefine       refine;
     94:   PEPRefineScheme scheme;

     98:   PEPRegisterAll();
     99:   PetscObjectOptionsBegin((PetscObject)pep);
    100:     PetscOptionsFList("-pep_type","Polynomial eigensolver method","PEPSetType",PEPList,(char*)(((PetscObject)pep)->type_name?((PetscObject)pep)->type_name:PEPTOAR),type,sizeof(type),&flg);
    101:     if (flg) {
    102:       PEPSetType(pep,type);
    103:     } else if (!((PetscObject)pep)->type_name) {
    104:       PEPSetType(pep,PEPTOAR);
    105:     }

    107:     PetscOptionsBoolGroupBegin("-pep_general","General polynomial eigenvalue problem","PEPSetProblemType",&flg);
    108:     if (flg) { PEPSetProblemType(pep,PEP_GENERAL); }
    109:     PetscOptionsBoolGroup("-pep_hermitian","Hermitian polynomial eigenvalue problem","PEPSetProblemType",&flg);
    110:     if (flg) { PEPSetProblemType(pep,PEP_HERMITIAN); }
    111:     PetscOptionsBoolGroup("-pep_hyperbolic","Hyperbolic polynomial eigenvalue problem","PEPSetProblemType",&flg);
    112:     if (flg) { PEPSetProblemType(pep,PEP_HYPERBOLIC); }
    113:     PetscOptionsBoolGroupEnd("-pep_gyroscopic","Gyroscopic polynomial eigenvalue problem","PEPSetProblemType",&flg);
    114:     if (flg) { PEPSetProblemType(pep,PEP_GYROSCOPIC); }

    116:     scale = pep->scale;
    117:     PetscOptionsEnum("-pep_scale","Scaling strategy","PEPSetScale",PEPScaleTypes,(PetscEnum)scale,(PetscEnum*)&scale,&flg1);
    118:     r = pep->sfactor;
    119:     PetscOptionsReal("-pep_scale_factor","Scale factor","PEPSetScale",pep->sfactor,&r,&flg2);
    120:     if (!flg2 && r==1.0) r = PETSC_DEFAULT;
    121:     j = pep->sits;
    122:     PetscOptionsInt("-pep_scale_its","Number of iterations in diagonal scaling","PEPSetScale",pep->sits,&j,&flg3);
    123:     t = pep->slambda;
    124:     PetscOptionsReal("-pep_scale_lambda","Estimate of eigenvalue (modulus) for diagonal scaling","PEPSetScale",pep->slambda,&t,&flg4);
    125:     if (flg1 || flg2 || flg3 || flg4) { PEPSetScale(pep,scale,r,NULL,NULL,j,t); }

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

    129:     refine = pep->refine;
    130:     PetscOptionsEnum("-pep_refine","Iterative refinement method","PEPSetRefine",PEPRefineTypes,(PetscEnum)refine,(PetscEnum*)&refine,&flg1);
    131:     i = pep->npart;
    132:     PetscOptionsInt("-pep_refine_partitions","Number of partitions of the communicator for iterative refinement","PEPSetRefine",pep->npart,&i,&flg2);
    133:     r = pep->rtol;
    134:     PetscOptionsReal("-pep_refine_tol","Tolerance for iterative refinement","PEPSetRefine",pep->rtol==PETSC_DEFAULT?SLEPC_DEFAULT_TOL/1000:pep->rtol,&r,&flg3);
    135:     j = pep->rits;
    136:     PetscOptionsInt("-pep_refine_its","Maximum number of iterations for iterative refinement","PEPSetRefine",pep->rits,&j,&flg4);
    137:     scheme = pep->scheme;
    138:     PetscOptionsEnum("-pep_refine_scheme","Scheme used for linear systems within iterative refinement","PEPSetRefine",PEPRefineSchemes,(PetscEnum)scheme,(PetscEnum*)&scheme,&flg5);
    139:     if (flg1 || flg2 || flg3 || flg4 || flg5) { PEPSetRefine(pep,refine,i,r,j,scheme); }

    141:     i = pep->max_it;
    142:     PetscOptionsInt("-pep_max_it","Maximum number of iterations","PEPSetTolerances",pep->max_it,&i,&flg1);
    143:     r = pep->tol;
    144:     PetscOptionsReal("-pep_tol","Tolerance","PEPSetTolerances",pep->tol==PETSC_DEFAULT?SLEPC_DEFAULT_TOL:pep->tol,&r,&flg2);
    145:     if (flg1 || flg2) { PEPSetTolerances(pep,r,i); }

    147:     PetscOptionsBoolGroupBegin("-pep_conv_rel","Relative error convergence test","PEPSetConvergenceTest",&flg);
    148:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_REL); }
    149:     PetscOptionsBoolGroup("-pep_conv_norm","Convergence test relative to the matrix norms","PEPSetConvergenceTest",&flg);
    150:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_NORM); }
    151:     PetscOptionsBoolGroup("-pep_conv_abs","Absolute error convergence test","PEPSetConvergenceTest",&flg);
    152:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_ABS); }
    153:     PetscOptionsBoolGroupEnd("-pep_conv_user","User-defined convergence test","PEPSetConvergenceTest",&flg);
    154:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_USER); }

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

    161:     i = pep->nev;
    162:     PetscOptionsInt("-pep_nev","Number of eigenvalues to compute","PEPSetDimensions",pep->nev,&i,&flg1);
    163:     j = pep->ncv;
    164:     PetscOptionsInt("-pep_ncv","Number of basis vectors","PEPSetDimensions",pep->ncv,&j,&flg2);
    165:     k = pep->mpd;
    166:     PetscOptionsInt("-pep_mpd","Maximum dimension of projected problem","PEPSetDimensions",pep->mpd,&k,&flg3);
    167:     if (flg1 || flg2 || flg3) { PEPSetDimensions(pep,i,j,k); }

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

    171:     PetscOptionsBoolGroupBegin("-pep_largest_magnitude","Compute largest eigenvalues in magnitude","PEPSetWhichEigenpairs",&flg);
    172:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_LARGEST_MAGNITUDE); }
    173:     PetscOptionsBoolGroup("-pep_smallest_magnitude","Compute smallest eigenvalues in magnitude","PEPSetWhichEigenpairs",&flg);
    174:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_SMALLEST_MAGNITUDE); }
    175:     PetscOptionsBoolGroup("-pep_largest_real","Compute eigenvalues with largest real parts","PEPSetWhichEigenpairs",&flg);
    176:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_LARGEST_REAL); }
    177:     PetscOptionsBoolGroup("-pep_smallest_real","Compute eigenvalues with smallest real parts","PEPSetWhichEigenpairs",&flg);
    178:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_SMALLEST_REAL); }
    179:     PetscOptionsBoolGroup("-pep_largest_imaginary","Compute eigenvalues with largest imaginary parts","PEPSetWhichEigenpairs",&flg);
    180:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_LARGEST_IMAGINARY); }
    181:     PetscOptionsBoolGroup("-pep_smallest_imaginary","Compute eigenvalues with smallest imaginary parts","PEPSetWhichEigenpairs",&flg);
    182:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_SMALLEST_IMAGINARY); }
    183:     PetscOptionsBoolGroup("-pep_target_magnitude","Compute eigenvalues closest to target","PEPSetWhichEigenpairs",&flg);
    184:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_TARGET_MAGNITUDE); }
    185:     PetscOptionsBoolGroup("-pep_target_real","Compute eigenvalues with real parts closest to target","PEPSetWhichEigenpairs",&flg);
    186:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_TARGET_REAL); }
    187:     PetscOptionsBoolGroup("-pep_target_imaginary","Compute eigenvalues with imaginary parts closest to target","PEPSetWhichEigenpairs",&flg);
    188:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_TARGET_IMAGINARY); }
    189:     PetscOptionsBoolGroupEnd("-pep_all","Compute all eigenvalues in an interval or a region","PEPSetWhichEigenpairs",&flg);
    190:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_ALL); }

    192:     PetscOptionsScalar("-pep_target","Value of the target","PEPSetTarget",pep->target,&s,&flg);
    193:     if (flg) {
    194:       if (pep->which!=PEP_TARGET_REAL && pep->which!=PEP_TARGET_IMAGINARY) {
    195:         PEPSetWhichEigenpairs(pep,PEP_TARGET_MAGNITUDE);
    196:       }
    197:       PEPSetTarget(pep,s);
    198:     }

    200:     k = 2;
    201:     PetscOptionsRealArray("-pep_interval","Computational interval (two real values separated with a comma without spaces)","PEPSetInterval",array,&k,&flg);
    202:     if (flg) {
    203:       if (k<2) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_SIZ,"Must pass two values in -pep_interval (comma-separated without spaces)");
    204:       PEPSetWhichEigenpairs(pep,PEP_ALL);
    205:       PEPSetInterval(pep,array[0],array[1]);
    206:     }

    208:     /* -----------------------------------------------------------------------*/
    209:     /*
    210:       Cancels all monitors hardwired into code before call to PEPSetFromOptions()
    211:     */
    212:     PetscOptionsBool("-pep_monitor_cancel","Remove any hardwired monitor routines","PEPMonitorCancel",PETSC_FALSE,&flg,&set);
    213:     if (set && flg) { PEPMonitorCancel(pep); }
    214:     PEPMonitorSetFromOptions(pep,"-pep_monitor","first_approximation",NULL,PETSC_FALSE);
    215:     PEPMonitorSetFromOptions(pep,"-pep_monitor_all","all_approximations",NULL,PETSC_TRUE);
    216:     PEPMonitorSetFromOptions(pep,"-pep_monitor_conv","convergence_history",NULL,PETSC_FALSE);

    218:     /* -----------------------------------------------------------------------*/
    219:     PetscOptionsName("-pep_view","Print detailed information on solver used","PEPView",NULL);
    220:     PetscOptionsName("-pep_view_vectors","View computed eigenvectors","PEPVectorsView",NULL);
    221:     PetscOptionsName("-pep_view_values","View computed eigenvalues","PEPValuesView",NULL);
    222:     PetscOptionsName("-pep_converged_reason","Print reason for convergence, and number of iterations","PEPConvergedReasonView",NULL);
    223:     PetscOptionsName("-pep_error_absolute","Print absolute errors of each eigenpair","PEPErrorView",NULL);
    224:     PetscOptionsName("-pep_error_relative","Print relative errors of each eigenpair","PEPErrorView",NULL);
    225:     PetscOptionsName("-pep_error_backward","Print backward errors of each eigenpair","PEPErrorView",NULL);

    227:     if (pep->ops->setfromoptions) {
    228:       (*pep->ops->setfromoptions)(PetscOptionsObject,pep);
    229:     }
    230:     PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)pep);
    231:   PetscOptionsEnd();

    233:   if (!pep->V) { PEPGetBV(pep,&pep->V); }
    234:   BVSetFromOptions(pep->V);
    235:   if (!pep->rg) { PEPGetRG(pep,&pep->rg); }
    236:   RGSetFromOptions(pep->rg);
    237:   if (!pep->ds) { PEPGetDS(pep,&pep->ds); }
    238:   DSSetFromOptions(pep->ds);
    239:   if (!pep->st) { PEPGetST(pep,&pep->st); }
    240:   PEPSetDefaultST(pep);
    241:   STSetFromOptions(pep->st);
    242:   if (!pep->refineksp) { PEPRefineGetKSP(pep,&pep->refineksp); }
    243:   KSPSetFromOptions(pep->refineksp);
    244:   return(0);
    245: }

    247: /*@C
    248:    PEPGetTolerances - Gets the tolerance and maximum iteration count used
    249:    by the PEP convergence tests.

    251:    Not Collective

    253:    Input Parameter:
    254: .  pep - the polynomial eigensolver context

    256:    Output Parameters:
    257: +  tol - the convergence tolerance
    258: -  maxits - maximum number of iterations

    260:    Notes:
    261:    The user can specify NULL for any parameter that is not needed.

    263:    Level: intermediate

    265: .seealso: PEPSetTolerances()
    266: @*/
    267: PetscErrorCode PEPGetTolerances(PEP pep,PetscReal *tol,PetscInt *maxits)
    268: {
    271:   if (tol)    *tol    = pep->tol;
    272:   if (maxits) *maxits = pep->max_it;
    273:   return(0);
    274: }

    276: /*@
    277:    PEPSetTolerances - Sets the tolerance and maximum iteration count used
    278:    by the PEP convergence tests.

    280:    Logically Collective on pep

    282:    Input Parameters:
    283: +  pep - the polynomial eigensolver context
    284: .  tol - the convergence tolerance
    285: -  maxits - maximum number of iterations to use

    287:    Options Database Keys:
    288: +  -pep_tol <tol> - Sets the convergence tolerance
    289: -  -pep_max_it <maxits> - Sets the maximum number of iterations allowed

    291:    Notes:
    292:    Use PETSC_DEFAULT for either argument to assign a reasonably good value.

    294:    Level: intermediate

    296: .seealso: PEPGetTolerances()
    297: @*/
    298: PetscErrorCode PEPSetTolerances(PEP pep,PetscReal tol,PetscInt maxits)
    299: {
    304:   if (tol == PETSC_DEFAULT) {
    305:     pep->tol   = PETSC_DEFAULT;
    306:     pep->state = PEP_STATE_INITIAL;
    307:   } else {
    308:     if (tol <= 0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    309:     pep->tol = tol;
    310:   }
    311:   if (maxits == PETSC_DEFAULT || maxits == PETSC_DECIDE) {
    312:     pep->max_it = PETSC_DEFAULT;
    313:     pep->state  = PEP_STATE_INITIAL;
    314:   } else {
    315:     if (maxits <= 0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
    316:     pep->max_it = maxits;
    317:   }
    318:   return(0);
    319: }

    321: /*@C
    322:    PEPGetDimensions - Gets the number of eigenvalues to compute
    323:    and the dimension of the subspace.

    325:    Not Collective

    327:    Input Parameter:
    328: .  pep - the polynomial eigensolver context

    330:    Output Parameters:
    331: +  nev - number of eigenvalues to compute
    332: .  ncv - the maximum dimension of the subspace to be used by the solver
    333: -  mpd - the maximum dimension allowed for the projected problem

    335:    Notes:
    336:    The user can specify NULL for any parameter that is not needed.

    338:    Level: intermediate

    340: .seealso: PEPSetDimensions()
    341: @*/
    342: PetscErrorCode PEPGetDimensions(PEP pep,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
    343: {
    346:   if (nev) *nev = pep->nev;
    347:   if (ncv) *ncv = pep->ncv;
    348:   if (mpd) *mpd = pep->mpd;
    349:   return(0);
    350: }

    352: /*@
    353:    PEPSetDimensions - Sets the number of eigenvalues to compute
    354:    and the dimension of the subspace.

    356:    Logically Collective on pep

    358:    Input Parameters:
    359: +  pep - the polynomial eigensolver context
    360: .  nev - number of eigenvalues to compute
    361: .  ncv - the maximum dimension of the subspace to be used by the solver
    362: -  mpd - the maximum dimension allowed for the projected problem

    364:    Options Database Keys:
    365: +  -pep_nev <nev> - Sets the number of eigenvalues
    366: .  -pep_ncv <ncv> - Sets the dimension of the subspace
    367: -  -pep_mpd <mpd> - Sets the maximum projected dimension

    369:    Notes:
    370:    Use PETSC_DEFAULT for ncv and mpd to assign a reasonably good value, which is
    371:    dependent on the solution method.

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

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

    382:    When computing all eigenvalues in an interval, see PEPSetInterval(), these
    383:    parameters lose relevance, and tuning must be done with PEPSTOARSetDimensions().

    385:    Level: intermediate

    387: .seealso: PEPGetDimensions(), PEPSetInterval(), PEPSTOARSetDimensions()
    388: @*/
    389: PetscErrorCode PEPSetDimensions(PEP pep,PetscInt nev,PetscInt ncv,PetscInt mpd)
    390: {
    396:   if (nev<1) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
    397:   pep->nev = nev;
    398:   if (ncv == PETSC_DECIDE || ncv == PETSC_DEFAULT) {
    399:     pep->ncv = PETSC_DEFAULT;
    400:   } else {
    401:     if (ncv<1) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
    402:     pep->ncv = ncv;
    403:   }
    404:   if (mpd == PETSC_DECIDE || mpd == PETSC_DEFAULT) {
    405:     pep->mpd = PETSC_DEFAULT;
    406:   } else {
    407:     if (mpd<1) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
    408:     pep->mpd = mpd;
    409:   }
    410:   pep->state = PEP_STATE_INITIAL;
    411:   return(0);
    412: }

    414: /*@
    415:    PEPSetWhichEigenpairs - Specifies which portion of the spectrum is
    416:    to be sought.

    418:    Logically Collective on pep

    420:    Input Parameters:
    421: +  pep   - eigensolver context obtained from PEPCreate()
    422: -  which - the portion of the spectrum to be sought

    424:    Possible values:
    425:    The parameter 'which' can have one of these values

    427: +     PEP_LARGEST_MAGNITUDE - largest eigenvalues in magnitude (default)
    428: .     PEP_SMALLEST_MAGNITUDE - smallest eigenvalues in magnitude
    429: .     PEP_LARGEST_REAL - largest real parts
    430: .     PEP_SMALLEST_REAL - smallest real parts
    431: .     PEP_LARGEST_IMAGINARY - largest imaginary parts
    432: .     PEP_SMALLEST_IMAGINARY - smallest imaginary parts
    433: .     PEP_TARGET_MAGNITUDE - eigenvalues closest to the target (in magnitude)
    434: .     PEP_TARGET_REAL - eigenvalues with real part closest to target
    435: .     PEP_TARGET_IMAGINARY - eigenvalues with imaginary part closest to target
    436: .     PEP_ALL - all eigenvalues contained in a given interval
    437: -     PEP_WHICH_USER - user defined ordering set with PEPSetEigenvalueComparison()

    439:    Options Database Keys:
    440: +   -pep_largest_magnitude - Sets largest eigenvalues in magnitude
    441: .   -pep_smallest_magnitude - Sets smallest eigenvalues in magnitude
    442: .   -pep_largest_real - Sets largest real parts
    443: .   -pep_smallest_real - Sets smallest real parts
    444: .   -pep_largest_imaginary - Sets largest imaginary parts
    445: .   -pep_smallest_imaginary - Sets smallest imaginary parts
    446: .   -pep_target_magnitude - Sets eigenvalues closest to target
    447: .   -pep_target_real - Sets real parts closest to target
    448: .   -pep_target_imaginary - Sets imaginary parts closest to target
    449: -   -pep_all - Sets all eigenvalues in an interval

    451:    Notes:
    452:    Not all eigensolvers implemented in PEP account for all the possible values
    453:    stated above. If SLEPc is compiled for real numbers PEP_LARGEST_IMAGINARY
    454:    and PEP_SMALLEST_IMAGINARY use the absolute value of the imaginary part
    455:    for eigenvalue selection.

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

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

    462:    PEP_ALL is intended for use in combination with an interval (see
    463:    PEPSetInterval()), when all eigenvalues within the interval are requested.
    464:    In that case, the number of eigenvalues is unknown, so the nev parameter
    465:    has a different sense, see PEPSetDimensions().

    467:    Level: intermediate

    469: .seealso: PEPGetWhichEigenpairs(), PEPSetTarget(), PEPSetInterval(),
    470:           PEPSetDimensions(), PEPSetEigenvalueComparison(), PEPWhich
    471: @*/
    472: PetscErrorCode PEPSetWhichEigenpairs(PEP pep,PEPWhich which)
    473: {
    477:   switch (which) {
    478:     case PEP_LARGEST_MAGNITUDE:
    479:     case PEP_SMALLEST_MAGNITUDE:
    480:     case PEP_LARGEST_REAL:
    481:     case PEP_SMALLEST_REAL:
    482:     case PEP_LARGEST_IMAGINARY:
    483:     case PEP_SMALLEST_IMAGINARY:
    484:     case PEP_TARGET_MAGNITUDE:
    485:     case PEP_TARGET_REAL:
    486: #if defined(PETSC_USE_COMPLEX)
    487:     case PEP_TARGET_IMAGINARY:
    488: #endif
    489:     case PEP_ALL:
    490:     case PEP_WHICH_USER:
    491:       if (pep->which != which) {
    492:         pep->state = PEP_STATE_INITIAL;
    493:         pep->which = which;
    494:       }
    495:       break;
    496: #if !defined(PETSC_USE_COMPLEX)
    497:     case PEP_TARGET_IMAGINARY:
    498:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_SUP,"PEP_TARGET_IMAGINARY can be used only with complex scalars");
    499: #endif
    500:     default:
    501:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'which' value");
    502:   }
    503:   return(0);
    504: }

    506: /*@
    507:     PEPGetWhichEigenpairs - Returns which portion of the spectrum is to be
    508:     sought.

    510:     Not Collective

    512:     Input Parameter:
    513: .   pep - eigensolver context obtained from PEPCreate()

    515:     Output Parameter:
    516: .   which - the portion of the spectrum to be sought

    518:     Notes:
    519:     See PEPSetWhichEigenpairs() for possible values of 'which'.

    521:     Level: intermediate

    523: .seealso: PEPSetWhichEigenpairs(), PEPWhich
    524: @*/
    525: PetscErrorCode PEPGetWhichEigenpairs(PEP pep,PEPWhich *which)
    526: {
    530:   *which = pep->which;
    531:   return(0);
    532: }

    534: /*@C
    535:    PEPSetEigenvalueComparison - Specifies the eigenvalue comparison function
    536:    when PEPSetWhichEigenpairs() is set to PEP_WHICH_USER.

    538:    Logically Collective on pep

    540:    Input Parameters:
    541: +  pep  - eigensolver context obtained from PEPCreate()
    542: .  func - a pointer to the comparison function
    543: -  ctx  - a context pointer (the last parameter to the comparison function)

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

    548: +   ar     - real part of the 1st eigenvalue
    549: .   ai     - imaginary part of the 1st eigenvalue
    550: .   br     - real part of the 2nd eigenvalue
    551: .   bi     - imaginary part of the 2nd eigenvalue
    552: .   res    - result of comparison
    553: -   ctx    - optional context, as set by PEPSetEigenvalueComparison()

    555:    Note:
    556:    The returning parameter 'res' can be
    557: +  negative - if the 1st eigenvalue is preferred to the 2st one
    558: .  zero     - if both eigenvalues are equally preferred
    559: -  positive - if the 2st eigenvalue is preferred to the 1st one

    561:    Level: advanced

    563: .seealso: PEPSetWhichEigenpairs(), PEPWhich
    564: @*/
    565: PetscErrorCode PEPSetEigenvalueComparison(PEP pep,PetscErrorCode (*func)(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*),void* ctx)
    566: {
    569:   pep->sc->comparison    = func;
    570:   pep->sc->comparisonctx = ctx;
    571:   pep->which             = PEP_WHICH_USER;
    572:   return(0);
    573: }

    575: /*@
    576:    PEPSetProblemType - Specifies the type of the polynomial eigenvalue problem.

    578:    Logically Collective on pep

    580:    Input Parameters:
    581: +  pep  - the polynomial eigensolver context
    582: -  type - a known type of polynomial eigenvalue problem

    584:    Options Database Keys:
    585: +  -pep_general - general problem with no particular structure
    586: .  -pep_hermitian - problem whose coefficient matrices are Hermitian
    587: .  -pep_hyperbolic - Hermitian problem that satisfies the definition of hyperbolic
    588: -  -pep_gyroscopic - problem with Hamiltonian structure

    590:    Notes:
    591:    Allowed values for the problem type are: general (PEP_GENERAL), Hermitian
    592:    (PEP_HERMITIAN), hyperbolic (PEP_HYPERBOLIC), and gyroscopic (PEP_GYROSCOPIC).

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

    597:    If the problem matrices are Hermitian (symmetric in the real case) or
    598:    Hermitian/skew-Hermitian then the solver can exploit this fact to perform
    599:    less operations or provide better stability. Hyperbolic problems are a
    600:    particular case of Hermitian problems, some solvers may treat them simply as
    601:    Hermitian.

    603:    Level: intermediate

    605: .seealso: PEPSetOperators(), PEPSetType(), PEPGetProblemType(), PEPProblemType
    606: @*/
    607: PetscErrorCode PEPSetProblemType(PEP pep,PEPProblemType type)
    608: {
    612:   if (type!=PEP_GENERAL && type!=PEP_HERMITIAN && type!=PEP_HYPERBOLIC && type!=PEP_GYROSCOPIC) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_WRONG,"Unknown eigenvalue problem type");
    613:   if (type != pep->problem_type) {
    614:     pep->problem_type = type;
    615:     pep->state = PEP_STATE_INITIAL;
    616:   }
    617:   return(0);
    618: }

    620: /*@
    621:    PEPGetProblemType - Gets the problem type from the PEP object.

    623:    Not Collective

    625:    Input Parameter:
    626: .  pep - the polynomial eigensolver context

    628:    Output Parameter:
    629: .  type - the problem type

    631:    Level: intermediate

    633: .seealso: PEPSetProblemType(), PEPProblemType
    634: @*/
    635: PetscErrorCode PEPGetProblemType(PEP pep,PEPProblemType *type)
    636: {
    640:   *type = pep->problem_type;
    641:   return(0);
    642: }

    644: /*@
    645:    PEPSetBasis - Specifies the type of polynomial basis used to describe the
    646:    polynomial eigenvalue problem.

    648:    Logically Collective on pep

    650:    Input Parameters:
    651: +  pep   - the polynomial eigensolver context
    652: -  basis - the type of polynomial basis

    654:    Options Database Key:
    655: .  -pep_basis <basis> - Select the basis type

    657:    Notes:
    658:    By default, the coefficient matrices passed via PEPSetOperators() are
    659:    expressed in the monomial basis, i.e.
    660:    P(lambda) = A_0 + lambda*A_1 + lambda^2*A_2 + ... + lambda^d*A_d.
    661:    Other polynomial bases may have better numerical behaviour, but the user
    662:    must then pass the coefficient matrices accordingly.

    664:    Level: intermediate

    666: .seealso: PEPSetOperators(), PEPGetBasis(), PEPBasis
    667: @*/
    668: PetscErrorCode PEPSetBasis(PEP pep,PEPBasis basis)
    669: {
    673:   pep->basis = basis;
    674:   return(0);
    675: }

    677: /*@
    678:    PEPGetBasis - Gets the type of polynomial basis from the PEP object.

    680:    Not Collective

    682:    Input Parameter:
    683: .  pep - the polynomial eigensolver context

    685:    Output Parameter:
    686: .  basis - the polynomial basis

    688:    Level: intermediate

    690: .seealso: PEPSetBasis(), PEPBasis
    691: @*/
    692: PetscErrorCode PEPGetBasis(PEP pep,PEPBasis *basis)
    693: {
    697:   *basis = pep->basis;
    698:   return(0);
    699: }

    701: /*@
    702:    PEPSetTrackAll - Specifies if the solver must compute the residual of all
    703:    approximate eigenpairs or not.

    705:    Logically Collective on pep

    707:    Input Parameters:
    708: +  pep      - the eigensolver context
    709: -  trackall - whether compute all residuals or not

    711:    Notes:
    712:    If the user sets trackall=PETSC_TRUE then the solver explicitly computes
    713:    the residual for each eigenpair approximation. Computing the residual is
    714:    usually an expensive operation and solvers commonly compute the associated
    715:    residual to the first unconverged eigenpair.

    717:    The option '-pep_monitor_all' automatically activates this option.

    719:    Level: developer

    721: .seealso: PEPGetTrackAll()
    722: @*/
    723: PetscErrorCode PEPSetTrackAll(PEP pep,PetscBool trackall)
    724: {
    728:   pep->trackall = trackall;
    729:   return(0);
    730: }

    732: /*@
    733:    PEPGetTrackAll - Returns the flag indicating whether all residual norms must
    734:    be computed or not.

    736:    Not Collective

    738:    Input Parameter:
    739: .  pep - the eigensolver context

    741:    Output Parameter:
    742: .  trackall - the returned flag

    744:    Level: developer

    746: .seealso: PEPSetTrackAll()
    747: @*/
    748: PetscErrorCode PEPGetTrackAll(PEP pep,PetscBool *trackall)
    749: {
    753:   *trackall = pep->trackall;
    754:   return(0);
    755: }

    757: /*@C
    758:    PEPSetConvergenceTestFunction - Sets a function to compute the error estimate
    759:    used in the convergence test.

    761:    Logically Collective on pep

    763:    Input Parameters:
    764: +  pep     - eigensolver context obtained from PEPCreate()
    765: .  func    - a pointer to the convergence test function
    766: .  ctx     - context for private data for the convergence routine (may be null)
    767: -  destroy - a routine for destroying the context (may be null)

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

    772: +   pep    - eigensolver context obtained from PEPCreate()
    773: .   eigr   - real part of the eigenvalue
    774: .   eigi   - imaginary part of the eigenvalue
    775: .   res    - residual norm associated to the eigenpair
    776: .   errest - (output) computed error estimate
    777: -   ctx    - optional context, as set by PEPSetConvergenceTestFunction()

    779:    Note:
    780:    If the error estimate returned by the convergence test function is less than
    781:    the tolerance, then the eigenvalue is accepted as converged.

    783:    Level: advanced

    785: .seealso: PEPSetConvergenceTest(), PEPSetTolerances()
    786: @*/
    787: PetscErrorCode PEPSetConvergenceTestFunction(PEP pep,PetscErrorCode (*func)(PEP,PetscScalar,PetscScalar,PetscReal,PetscReal*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    788: {

    793:   if (pep->convergeddestroy) {
    794:     (*pep->convergeddestroy)(pep->convergedctx);
    795:   }
    796:   pep->convergeduser    = func;
    797:   pep->convergeddestroy = destroy;
    798:   pep->convergedctx     = ctx;
    799:   if (func == PEPConvergedRelative) pep->conv = PEP_CONV_REL;
    800:   else if (func == PEPConvergedNorm) pep->conv = PEP_CONV_NORM;
    801:   else if (func == PEPConvergedAbsolute) pep->conv = PEP_CONV_ABS;
    802:   else {
    803:     pep->conv      = PEP_CONV_USER;
    804:     pep->converged = pep->convergeduser;
    805:   }
    806:   return(0);
    807: }

    809: /*@
    810:    PEPSetConvergenceTest - Specifies how to compute the error estimate
    811:    used in the convergence test.

    813:    Logically Collective on pep

    815:    Input Parameters:
    816: +  pep  - eigensolver context obtained from PEPCreate()
    817: -  conv - the type of convergence test

    819:    Options Database Keys:
    820: +  -pep_conv_abs    - Sets the absolute convergence test
    821: .  -pep_conv_rel    - Sets the convergence test relative to the eigenvalue
    822: .  -pep_conv_norm   - Sets the convergence test relative to the matrix norms
    823: -  -pep_conv_user   - Selects the user-defined convergence test

    825:    Note:
    826:    The parameter 'conv' can have one of these values
    827: +     PEP_CONV_ABS    - absolute error ||r||
    828: .     PEP_CONV_REL    - error relative to the eigenvalue l, ||r||/|l|
    829: .     PEP_CONV_NORM   - error relative matrix norms, ||r||/sum_i(l^i*||A_i||)
    830: -     PEP_CONV_USER   - function set by PEPSetConvergenceTestFunction()

    832:    Level: intermediate

    834: .seealso: PEPGetConvergenceTest(), PEPSetConvergenceTestFunction(), PEPSetStoppingTest(), PEPConv
    835: @*/
    836: PetscErrorCode PEPSetConvergenceTest(PEP pep,PEPConv conv)
    837: {
    841:   switch (conv) {
    842:     case PEP_CONV_ABS:  pep->converged = PEPConvergedAbsolute; break;
    843:     case PEP_CONV_REL:  pep->converged = PEPConvergedRelative; break;
    844:     case PEP_CONV_NORM: pep->converged = PEPConvergedNorm; break;
    845:     case PEP_CONV_USER:
    846:       if (!pep->convergeduser) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ORDER,"Must call PEPSetConvergenceTestFunction() first");
    847:       pep->converged = pep->convergeduser;
    848:       break;
    849:     default:
    850:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'conv' value");
    851:   }
    852:   pep->conv = conv;
    853:   return(0);
    854: }

    856: /*@
    857:    PEPGetConvergenceTest - Gets the method used to compute the error estimate
    858:    used in the convergence test.

    860:    Not Collective

    862:    Input Parameters:
    863: .  pep   - eigensolver context obtained from PEPCreate()

    865:    Output Parameters:
    866: .  conv  - the type of convergence test

    868:    Level: intermediate

    870: .seealso: PEPSetConvergenceTest(), PEPConv
    871: @*/
    872: PetscErrorCode PEPGetConvergenceTest(PEP pep,PEPConv *conv)
    873: {
    877:   *conv = pep->conv;
    878:   return(0);
    879: }

    881: /*@C
    882:    PEPSetStoppingTestFunction - Sets a function to decide when to stop the outer
    883:    iteration of the eigensolver.

    885:    Logically Collective on pep

    887:    Input Parameters:
    888: +  pep     - eigensolver context obtained from PEPCreate()
    889: .  func    - pointer to the stopping test function
    890: .  ctx     - context for private data for the stopping routine (may be null)
    891: -  destroy - a routine for destroying the context (may be null)

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

    896: +   pep    - eigensolver context obtained from PEPCreate()
    897: .   its    - current number of iterations
    898: .   max_it - maximum number of iterations
    899: .   nconv  - number of currently converged eigenpairs
    900: .   nev    - number of requested eigenpairs
    901: .   reason - (output) result of the stopping test
    902: -   ctx    - optional context, as set by PEPSetStoppingTestFunction()

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

    910:    Level: advanced

    912: .seealso: PEPSetStoppingTest(), PEPStoppingBasic()
    913: @*/
    914: PetscErrorCode PEPSetStoppingTestFunction(PEP pep,PetscErrorCode (*func)(PEP,PetscInt,PetscInt,PetscInt,PetscInt,PEPConvergedReason*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    915: {

    920:   if (pep->stoppingdestroy) {
    921:     (*pep->stoppingdestroy)(pep->stoppingctx);
    922:   }
    923:   pep->stoppinguser    = func;
    924:   pep->stoppingdestroy = destroy;
    925:   pep->stoppingctx     = ctx;
    926:   if (func == PEPStoppingBasic) pep->stop = PEP_STOP_BASIC;
    927:   else {
    928:     pep->stop     = PEP_STOP_USER;
    929:     pep->stopping = pep->stoppinguser;
    930:   }
    931:   return(0);
    932: }

    934: /*@
    935:    PEPSetStoppingTest - Specifies how to decide the termination of the outer
    936:    loop of the eigensolver.

    938:    Logically Collective on pep

    940:    Input Parameters:
    941: +  pep  - eigensolver context obtained from PEPCreate()
    942: -  stop - the type of stopping test

    944:    Options Database Keys:
    945: +  -pep_stop_basic - Sets the default stopping test
    946: -  -pep_stop_user  - Selects the user-defined stopping test

    948:    Note:
    949:    The parameter 'stop' can have one of these values
    950: +     PEP_STOP_BASIC - default stopping test
    951: -     PEP_STOP_USER  - function set by PEPSetStoppingTestFunction()

    953:    Level: advanced

    955: .seealso: PEPGetStoppingTest(), PEPSetStoppingTestFunction(), PEPSetConvergenceTest(), PEPStop
    956: @*/
    957: PetscErrorCode PEPSetStoppingTest(PEP pep,PEPStop stop)
    958: {
    962:   switch (stop) {
    963:     case PEP_STOP_BASIC: pep->stopping = PEPStoppingBasic; break;
    964:     case PEP_STOP_USER:
    965:       if (!pep->stoppinguser) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ORDER,"Must call PEPSetStoppingTestFunction() first");
    966:       pep->stopping = pep->stoppinguser;
    967:       break;
    968:     default:
    969:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'stop' value");
    970:   }
    971:   pep->stop = stop;
    972:   return(0);
    973: }

    975: /*@
    976:    PEPGetStoppingTest - Gets the method used to decide the termination of the outer
    977:    loop of the eigensolver.

    979:    Not Collective

    981:    Input Parameters:
    982: .  pep   - eigensolver context obtained from PEPCreate()

    984:    Output Parameters:
    985: .  stop  - the type of stopping test

    987:    Level: advanced

    989: .seealso: PEPSetStoppingTest(), PEPStop
    990: @*/
    991: PetscErrorCode PEPGetStoppingTest(PEP pep,PEPStop *stop)
    992: {
    996:   *stop = pep->stop;
    997:   return(0);
    998: }

    1000: /*@
    1001:    PEPSetScale - Specifies the scaling strategy to be used.

    1003:    Logically Collective on pep

    1005:    Input Parameters:
    1006: +  pep    - the eigensolver context
    1007: .  scale  - scaling strategy
    1008: .  alpha  - the scaling factor used in the scalar strategy
    1009: .  Dl     - the left diagonal matrix of the diagonal scaling algorithm
    1010: .  Dr     - the right diagonal matrix of the diagonal scaling algorithm
    1011: .  its    - number of iterations of the diagonal scaling algorithm
    1012: -  lambda - approximation to wanted eigenvalues (modulus)

    1014:    Options Database Keys:
    1015: +  -pep_scale <type> - scaling type, one of <none,scalar,diagonal,both>
    1016: .  -pep_scale_factor <alpha> - the scaling factor
    1017: .  -pep_scale_its <its> - number of iterations
    1018: -  -pep_scale_lambda <lambda> - approximation to eigenvalues

    1020:    Notes:
    1021:    There are two non-exclusive scaling strategies: scalar and diagonal.

    1023:    In the scalar strategy, scaling is applied to the eigenvalue, that is,
    1024:    mu = lambda/alpha is the new eigenvalue and all matrices are scaled
    1025:    accordingly. After solving the scaled problem, the original lambda is
    1026:    recovered. Parameter 'alpha' must be positive. Use PETSC_DEFAULT to let
    1027:    the solver compute a reasonable scaling factor.

    1029:    In the diagonal strategy, the solver works implicitly with matrix Dl*A*Dr,
    1030:    where Dl and Dr are appropriate diagonal matrices. This improves the accuracy
    1031:    of the computed results in some cases. The user may provide the Dr and Dl
    1032:    matrices represented as Vec objects storing diagonal elements. If not
    1033:    provided, these matrices are computed internally. This option requires
    1034:    that the polynomial coefficient matrices are of MATAIJ type.
    1035:    The parameter 'its' is the number of iterations performed by the method.
    1036:    Parameter 'lambda' must be positive. Use PETSC_DEFAULT or set lambda = 1.0 if
    1037:    no information about eigenvalues is available.

    1039:    Level: intermediate

    1041: .seealso: PEPGetScale()
    1042: @*/
    1043: PetscErrorCode PEPSetScale(PEP pep,PEPScale scale,PetscReal alpha,Vec Dl,Vec Dr,PetscInt its,PetscReal lambda)
    1044: {

    1050:   pep->scale = scale;
    1051:   if (scale==PEP_SCALE_SCALAR || scale==PEP_SCALE_BOTH) {
    1053:     if (alpha == PETSC_DEFAULT || alpha == PETSC_DECIDE) {
    1054:       pep->sfactor = 0.0;
    1055:       pep->sfactor_set = PETSC_FALSE;
    1056:     } else {
    1057:       if (alpha<=0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of alpha. Must be > 0");
    1058:       pep->sfactor = alpha;
    1059:       pep->sfactor_set = PETSC_TRUE;
    1060:     }
    1061:   }
    1062:   if (scale==PEP_SCALE_DIAGONAL || scale==PEP_SCALE_BOTH) {
    1063:     if (Dl) {
    1066:       PetscObjectReference((PetscObject)Dl);
    1067:       VecDestroy(&pep->Dl);
    1068:       pep->Dl = Dl;
    1069:     }
    1070:     if (Dr) {
    1073:       PetscObjectReference((PetscObject)Dr);
    1074:       VecDestroy(&pep->Dr);
    1075:       pep->Dr = Dr;
    1076:     }
    1079:     if (its==PETSC_DECIDE || its==PETSC_DEFAULT) pep->sits = 5;
    1080:     else pep->sits = its;
    1081:     if (lambda==PETSC_DECIDE || lambda==PETSC_DEFAULT) pep->slambda = 1.0;
    1082:     else if (lambda<=0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of lambda. Must be > 0");
    1083:     else pep->slambda = lambda;
    1084:   }
    1085:   pep->state = PEP_STATE_INITIAL;
    1086:   return(0);
    1087: }

    1089: /*@C
    1090:    PEPGetScale - Gets the scaling strategy used by the PEP object, and the
    1091:    associated parameters.

    1093:    Not Collectiv, but vectors are shared by all processors that share the PEP

    1095:    Input Parameter:
    1096: .  pep - the eigensolver context

    1098:    Output Parameters:
    1099: +  scale  - scaling strategy
    1100: .  alpha  - the scaling factor used in the scalar strategy
    1101: .  Dl     - the left diagonal matrix of the diagonal scaling algorithm
    1102: .  Dr     - the right diagonal matrix of the diagonal scaling algorithm
    1103: .  its    - number of iterations of the diagonal scaling algorithm
    1104: -  lambda - approximation to wanted eigenvalues (modulus)

    1106:    Level: intermediate

    1108:    Note:
    1109:    The user can specify NULL for any parameter that is not needed.

    1111:    If Dl or Dr were not set by the user, then the ones computed internally are
    1112:    returned (or a null pointer if called before PEPSetUp).

    1114: .seealso: PEPSetScale(), PEPSetUp()
    1115: @*/
    1116: PetscErrorCode PEPGetScale(PEP pep,PEPScale *scale,PetscReal *alpha,Vec *Dl,Vec *Dr,PetscInt *its,PetscReal *lambda)
    1117: {
    1120:   if (scale)  *scale  = pep->scale;
    1121:   if (alpha)  *alpha  = pep->sfactor;
    1122:   if (Dl)     *Dl     = pep->Dl;
    1123:   if (Dr)     *Dr     = pep->Dr;
    1124:   if (its)    *its    = pep->sits;
    1125:   if (lambda) *lambda = pep->slambda;
    1126:   return(0);
    1127: }

    1129: /*@
    1130:    PEPSetExtract - Specifies the extraction strategy to be used.

    1132:    Logically Collective on pep

    1134:    Input Parameters:
    1135: +  pep     - the eigensolver context
    1136: -  extract - extraction strategy

    1138:    Options Database Keys:
    1139: .  -pep_extract <type> - extraction type, one of <none,norm,residual,structured>

    1141:    Level: intermediate

    1143: .seealso: PEPGetExtract()
    1144: @*/
    1145: PetscErrorCode PEPSetExtract(PEP pep,PEPExtract extract)
    1146: {
    1150:   pep->extract = extract;
    1151:   return(0);
    1152: }

    1154: /*@
    1155:    PEPGetExtract - Gets the extraction strategy used by the PEP object.

    1157:    Not Collective

    1159:    Input Parameter:
    1160: .  pep - the eigensolver context

    1162:    Output Parameter:
    1163: .  extract - extraction strategy

    1165:    Level: intermediate

    1167: .seealso: PEPSetExtract(), PEPExtract
    1168: @*/
    1169: PetscErrorCode PEPGetExtract(PEP pep,PEPExtract *extract)
    1170: {
    1174:   *extract = pep->extract;
    1175:   return(0);
    1176: }

    1178: /*@
    1179:    PEPSetRefine - Specifies the refinement type (and options) to be used
    1180:    after the solve.

    1182:    Logically Collective on pep

    1184:    Input Parameters:
    1185: +  pep    - the polynomial eigensolver context
    1186: .  refine - refinement type
    1187: .  npart  - number of partitions of the communicator
    1188: .  tol    - the convergence tolerance
    1189: .  its    - maximum number of refinement iterations
    1190: -  scheme - which scheme to be used for solving the involved linear systems

    1192:    Options Database Keys:
    1193: +  -pep_refine <type> - refinement type, one of <none,simple,multiple>
    1194: .  -pep_refine_partitions <n> - the number of partitions
    1195: .  -pep_refine_tol <tol> - the tolerance
    1196: .  -pep_refine_its <its> - number of iterations
    1197: -  -pep_refine_scheme - to set the scheme for the linear solves

    1199:    Notes:
    1200:    By default, iterative refinement is disabled, since it may be very
    1201:    costly. There are two possible refinement strategies: simple and multiple.
    1202:    The simple approach performs iterative refinement on each of the
    1203:    converged eigenpairs individually, whereas the multiple strategy works
    1204:    with the invariant pair as a whole, refining all eigenpairs simultaneously.
    1205:    The latter may be required for the case of multiple eigenvalues.

    1207:    In some cases, especially when using direct solvers within the
    1208:    iterative refinement method, it may be helpful for improved scalability
    1209:    to split the communicator in several partitions. The npart parameter
    1210:    indicates how many partitions to use (defaults to 1).

    1212:    The tol and its parameters specify the stopping criterion. In the simple
    1213:    method, refinement continues until the residual of each eigenpair is
    1214:    below the tolerance (tol defaults to the PEP tol, but may be set to a
    1215:    different value). In contrast, the multiple method simply performs its
    1216:    refinement iterations (just one by default).

    1218:    The scheme argument is used to change the way in which linear systems are
    1219:    solved. Possible choices are: explicit, mixed block elimination (MBE),
    1220:    and Schur complement.

    1222:    Level: intermediate

    1224: .seealso: PEPGetRefine()
    1225: @*/
    1226: PetscErrorCode PEPSetRefine(PEP pep,PEPRefine refine,PetscInt npart,PetscReal tol,PetscInt its,PEPRefineScheme scheme)
    1227: {
    1229:   PetscMPIInt    size;

    1238:   pep->refine = refine;
    1239:   if (refine) {  /* process parameters only if not REFINE_NONE */
    1240:     if (npart!=pep->npart) {
    1241:       PetscSubcommDestroy(&pep->refinesubc);
    1242:       KSPDestroy(&pep->refineksp);
    1243:     }
    1244:     if (npart == PETSC_DEFAULT || npart == PETSC_DECIDE) {
    1245:       pep->npart = 1;
    1246:     } else {
    1247:       MPI_Comm_size(PetscObjectComm((PetscObject)pep),&size);CHKERRMPI(ierr);
    1248:       if (npart<1 || npart>size) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of npart");
    1249:       pep->npart = npart;
    1250:     }
    1251:     if (tol == PETSC_DEFAULT || tol == PETSC_DECIDE) {
    1252:       pep->rtol = PETSC_DEFAULT;
    1253:     } else {
    1254:       if (tol<=0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    1255:       pep->rtol = tol;
    1256:     }
    1257:     if (its==PETSC_DECIDE || its==PETSC_DEFAULT) {
    1258:       pep->rits = PETSC_DEFAULT;
    1259:     } else {
    1260:       if (its<0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be >= 0");
    1261:       pep->rits = its;
    1262:     }
    1263:     pep->scheme = scheme;
    1264:   }
    1265:   pep->state = PEP_STATE_INITIAL;
    1266:   return(0);
    1267: }

    1269: /*@C
    1270:    PEPGetRefine - Gets the refinement strategy used by the PEP object, and the
    1271:    associated parameters.

    1273:    Not Collective

    1275:    Input Parameter:
    1276: .  pep - the polynomial eigensolver context

    1278:    Output Parameters:
    1279: +  refine - refinement type
    1280: .  npart  - number of partitions of the communicator
    1281: .  tol    - the convergence tolerance
    1282: .  its    - maximum number of refinement iterations
    1283: -  scheme - the scheme used for solving linear systems

    1285:    Level: intermediate

    1287:    Note:
    1288:    The user can specify NULL for any parameter that is not needed.

    1290: .seealso: PEPSetRefine()
    1291: @*/
    1292: PetscErrorCode PEPGetRefine(PEP pep,PEPRefine *refine,PetscInt *npart,PetscReal *tol,PetscInt *its,PEPRefineScheme *scheme)
    1293: {
    1296:   if (refine) *refine = pep->refine;
    1297:   if (npart)  *npart  = pep->npart;
    1298:   if (tol)    *tol    = pep->rtol;
    1299:   if (its)    *its    = pep->rits;
    1300:   if (scheme) *scheme = pep->scheme;
    1301:   return(0);
    1302: }

    1304: /*@C
    1305:    PEPSetOptionsPrefix - Sets the prefix used for searching for all
    1306:    PEP options in the database.

    1308:    Logically Collective on pep

    1310:    Input Parameters:
    1311: +  pep - the polynomial eigensolver context
    1312: -  prefix - the prefix string to prepend to all PEP option requests

    1314:    Notes:
    1315:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1316:    The first character of all runtime options is AUTOMATICALLY the
    1317:    hyphen.

    1319:    For example, to distinguish between the runtime options for two
    1320:    different PEP contexts, one could call
    1321: .vb
    1322:       PEPSetOptionsPrefix(pep1,"qeig1_")
    1323:       PEPSetOptionsPrefix(pep2,"qeig2_")
    1324: .ve

    1326:    Level: advanced

    1328: .seealso: PEPAppendOptionsPrefix(), PEPGetOptionsPrefix()
    1329: @*/
    1330: PetscErrorCode PEPSetOptionsPrefix(PEP pep,const char *prefix)
    1331: {

    1336:   if (!pep->st) { PEPGetST(pep,&pep->st); }
    1337:   STSetOptionsPrefix(pep->st,prefix);
    1338:   if (!pep->V) { PEPGetBV(pep,&pep->V); }
    1339:   BVSetOptionsPrefix(pep->V,prefix);
    1340:   if (!pep->ds) { PEPGetDS(pep,&pep->ds); }
    1341:   DSSetOptionsPrefix(pep->ds,prefix);
    1342:   if (!pep->rg) { PEPGetRG(pep,&pep->rg); }
    1343:   RGSetOptionsPrefix(pep->rg,prefix);
    1344:   PetscObjectSetOptionsPrefix((PetscObject)pep,prefix);
    1345:   return(0);
    1346: }

    1348: /*@C
    1349:    PEPAppendOptionsPrefix - Appends to the prefix used for searching for all
    1350:    PEP options in the database.

    1352:    Logically Collective on pep

    1354:    Input Parameters:
    1355: +  pep - the polynomial eigensolver context
    1356: -  prefix - the prefix string to prepend to all PEP option requests

    1358:    Notes:
    1359:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1360:    The first character of all runtime options is AUTOMATICALLY the hyphen.

    1362:    Level: advanced

    1364: .seealso: PEPSetOptionsPrefix(), PEPGetOptionsPrefix()
    1365: @*/
    1366: PetscErrorCode PEPAppendOptionsPrefix(PEP pep,const char *prefix)
    1367: {

    1372:   if (!pep->st) { PEPGetST(pep,&pep->st); }
    1373:   STAppendOptionsPrefix(pep->st,prefix);
    1374:   if (!pep->V) { PEPGetBV(pep,&pep->V); }
    1375:   BVAppendOptionsPrefix(pep->V,prefix);
    1376:   if (!pep->ds) { PEPGetDS(pep,&pep->ds); }
    1377:   DSAppendOptionsPrefix(pep->ds,prefix);
    1378:   if (!pep->rg) { PEPGetRG(pep,&pep->rg); }
    1379:   RGAppendOptionsPrefix(pep->rg,prefix);
    1380:   PetscObjectAppendOptionsPrefix((PetscObject)pep,prefix);
    1381:   return(0);
    1382: }

    1384: /*@C
    1385:    PEPGetOptionsPrefix - Gets the prefix used for searching for all
    1386:    PEP options in the database.

    1388:    Not Collective

    1390:    Input Parameters:
    1391: .  pep - the polynomial eigensolver context

    1393:    Output Parameters:
    1394: .  prefix - pointer to the prefix string used is returned

    1396:    Note:
    1397:    On the Fortran side, the user should pass in a string 'prefix' of
    1398:    sufficient length to hold the prefix.

    1400:    Level: advanced

    1402: .seealso: PEPSetOptionsPrefix(), PEPAppendOptionsPrefix()
    1403: @*/
    1404: PetscErrorCode PEPGetOptionsPrefix(PEP pep,const char *prefix[])
    1405: {

    1411:   PetscObjectGetOptionsPrefix((PetscObject)pep,prefix);
    1412:   return(0);
    1413: }