Date: 2021-02-01T14:42:15+00:00

Actual source code: nepopts.c
slepc-3.14.2 2021-02-01
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2020, 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:    NEP routines related to options that can be set via the command-line
     12:    or procedurally
     13: */

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

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

     22:    Collective on nep

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

     32:    Level: developer

     34: .seealso: NEPMonitorSet(), NEPSetTrackAll(), NEPConvMonitorSetFromOptions()
     35: @*/
     36: PetscErrorCode NEPMonitorSetFromOptions(NEP nep,const char name[],const char help[],const char manual[],PetscErrorCode (*monitor)(NEP,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,PetscViewerAndFormat*),PetscBool trackall)
     37: {
     38:   PetscErrorCode       ierr;
     39:   PetscBool            flg;
     40:   PetscViewer          viewer;
     41:   PetscViewerFormat    format;
     42:   PetscViewerAndFormat *vf;

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

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

     61:    Collective on nep

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

     70:    Level: developer

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

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

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

     97:    Collective on nep

     99:    Input Parameters:
    100: .  nep - the nonlinear eigensolver context

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

    105:    Level: beginner
    106: @*/
    107: PetscErrorCode NEPSetFromOptions(NEP nep)
    108: {
    109:   PetscErrorCode  ierr;
    110:   char            type[256];
    111:   PetscBool       set,flg,flg1,flg2,flg3,flg4,flg5,bval;
    112:   PetscReal       r;
    113:   PetscScalar     s;
    114:   PetscInt        i,j,k;
    115:   PetscDrawLG     lg;
    116:   NEPRefine       refine;
    117:   NEPRefineScheme scheme;

    121:   NEPRegisterAll();
    122:   PetscObjectOptionsBegin((PetscObject)nep);
    123:     PetscOptionsFList("-nep_type","Nonlinear eigensolver method","NEPSetType",NEPList,(char*)(((PetscObject)nep)->type_name?((PetscObject)nep)->type_name:NEPRII),type,sizeof(type),&flg);
    124:     if (flg) {
    125:       NEPSetType(nep,type);
    126:     } else if (!((PetscObject)nep)->type_name) {
    127:       NEPSetType(nep,NEPRII);
    128:     }

    130:     PetscOptionsBoolGroupBegin("-nep_general","General nonlinear eigenvalue problem","NEPSetProblemType",&flg);
    131:     if (flg) { NEPSetProblemType(nep,NEP_GENERAL); }
    132:     PetscOptionsBoolGroupEnd("-nep_rational","Rational eigenvalue problem","NEPSetProblemType",&flg);
    133:     if (flg) { NEPSetProblemType(nep,NEP_RATIONAL); }

    135:     refine = nep->refine;
    136:     PetscOptionsEnum("-nep_refine","Iterative refinement method","NEPSetRefine",NEPRefineTypes,(PetscEnum)refine,(PetscEnum*)&refine,&flg1);
    137:     i = nep->npart;
    138:     PetscOptionsInt("-nep_refine_partitions","Number of partitions of the communicator for iterative refinement","NEPSetRefine",nep->npart,&i,&flg2);
    139:     r = nep->rtol;
    140:     PetscOptionsReal("-nep_refine_tol","Tolerance for iterative refinement","NEPSetRefine",nep->rtol==PETSC_DEFAULT?SLEPC_DEFAULT_TOL/1000:nep->rtol,&r,&flg3);
    141:     j = nep->rits;
    142:     PetscOptionsInt("-nep_refine_its","Maximum number of iterations for iterative refinement","NEPSetRefine",nep->rits,&j,&flg4);
    143:     scheme = nep->scheme;
    144:     PetscOptionsEnum("-nep_refine_scheme","Scheme used for linear systems within iterative refinement","NEPSetRefine",NEPRefineSchemes,(PetscEnum)scheme,(PetscEnum*)&scheme,&flg5);
    145:     if (flg1 || flg2 || flg3 || flg4 || flg5) { NEPSetRefine(nep,refine,i,r,j,scheme); }

    147:     i = nep->max_it;
    148:     PetscOptionsInt("-nep_max_it","Maximum number of iterations","NEPSetTolerances",nep->max_it,&i,&flg1);
    149:     r = nep->tol;
    150:     PetscOptionsReal("-nep_tol","Tolerance","NEPSetTolerances",nep->tol==PETSC_DEFAULT?SLEPC_DEFAULT_TOL:nep->tol,&r,&flg2);
    151:     if (flg1 || flg2) { NEPSetTolerances(nep,r,i); }

    153:     PetscOptionsBoolGroupBegin("-nep_conv_rel","Relative error convergence test","NEPSetConvergenceTest",&flg);
    154:     if (flg) { NEPSetConvergenceTest(nep,NEP_CONV_REL); }
    155:     PetscOptionsBoolGroup("-nep_conv_norm","Convergence test relative to the matrix norms","NEPSetConvergenceTest",&flg);
    156:     if (flg) { NEPSetConvergenceTest(nep,NEP_CONV_NORM); }
    157:     PetscOptionsBoolGroup("-nep_conv_abs","Absolute error convergence test","NEPSetConvergenceTest",&flg);
    158:     if (flg) { NEPSetConvergenceTest(nep,NEP_CONV_ABS); }
    159:     PetscOptionsBoolGroupEnd("-nep_conv_user","User-defined convergence test","NEPSetConvergenceTest",&flg);
    160:     if (flg) { NEPSetConvergenceTest(nep,NEP_CONV_USER); }

    162:     PetscOptionsBoolGroupBegin("-nep_stop_basic","Stop iteration if all eigenvalues converged or max_it reached","NEPSetStoppingTest",&flg);
    163:     if (flg) { NEPSetStoppingTest(nep,NEP_STOP_BASIC); }
    164:     PetscOptionsBoolGroupEnd("-nep_stop_user","User-defined stopping test","NEPSetStoppingTest",&flg);
    165:     if (flg) { NEPSetStoppingTest(nep,NEP_STOP_USER); }

    167:     i = nep->nev;
    168:     PetscOptionsInt("-nep_nev","Number of eigenvalues to compute","NEPSetDimensions",nep->nev,&i,&flg1);
    169:     j = nep->ncv;
    170:     PetscOptionsInt("-nep_ncv","Number of basis vectors","NEPSetDimensions",nep->ncv,&j,&flg2);
    171:     k = nep->mpd;
    172:     PetscOptionsInt("-nep_mpd","Maximum dimension of projected problem","NEPSetDimensions",nep->mpd,&k,&flg3);
    173:     if (flg1 || flg2 || flg3) {
    174:       NEPSetDimensions(nep,i,j,k);
    175:     }

    177:     PetscOptionsBoolGroupBegin("-nep_largest_magnitude","Compute largest eigenvalues in magnitude","NEPSetWhichEigenpairs",&flg);
    178:     if (flg) { NEPSetWhichEigenpairs(nep,NEP_LARGEST_MAGNITUDE); }
    179:     PetscOptionsBoolGroup("-nep_smallest_magnitude","Compute smallest eigenvalues in magnitude","NEPSetWhichEigenpairs",&flg);
    180:     if (flg) { NEPSetWhichEigenpairs(nep,NEP_SMALLEST_MAGNITUDE); }
    181:     PetscOptionsBoolGroup("-nep_largest_real","Compute eigenvalues with largest real parts","NEPSetWhichEigenpairs",&flg);
    182:     if (flg) { NEPSetWhichEigenpairs(nep,NEP_LARGEST_REAL); }
    183:     PetscOptionsBoolGroup("-nep_smallest_real","Compute eigenvalues with smallest real parts","NEPSetWhichEigenpairs",&flg);
    184:     if (flg) { NEPSetWhichEigenpairs(nep,NEP_SMALLEST_REAL); }
    185:     PetscOptionsBoolGroup("-nep_largest_imaginary","Compute eigenvalues with largest imaginary parts","NEPSetWhichEigenpairs",&flg);
    186:     if (flg) { NEPSetWhichEigenpairs(nep,NEP_LARGEST_IMAGINARY); }
    187:     PetscOptionsBoolGroup("-nep_smallest_imaginary","Compute eigenvalues with smallest imaginary parts","NEPSetWhichEigenpairs",&flg);
    188:     if (flg) { NEPSetWhichEigenpairs(nep,NEP_SMALLEST_IMAGINARY); }
    189:     PetscOptionsBoolGroup("-nep_target_magnitude","Compute eigenvalues closest to target","NEPSetWhichEigenpairs",&flg);
    190:     if (flg) { NEPSetWhichEigenpairs(nep,NEP_TARGET_MAGNITUDE); }
    191:     PetscOptionsBoolGroup("-nep_target_real","Compute eigenvalues with real parts closest to target","NEPSetWhichEigenpairs",&flg);
    192:     if (flg) { NEPSetWhichEigenpairs(nep,NEP_TARGET_REAL); }
    193:     PetscOptionsBoolGroup("-nep_target_imaginary","Compute eigenvalues with imaginary parts closest to target","NEPSetWhichEigenpairs",&flg);
    194:     if (flg) { NEPSetWhichEigenpairs(nep,NEP_TARGET_IMAGINARY); }
    195:     PetscOptionsBoolGroupEnd("-nep_all","Compute all eigenvalues in a region","NEPSetWhichEigenpairs",&flg);
    196:     if (flg) { NEPSetWhichEigenpairs(nep,NEP_ALL); }

    198:     PetscOptionsScalar("-nep_target","Value of the target","NEPSetTarget",nep->target,&s,&flg);
    199:     if (flg) {
    200:       if (nep->which!=NEP_TARGET_REAL && nep->which!=NEP_TARGET_IMAGINARY) {
    201:         NEPSetWhichEigenpairs(nep,NEP_TARGET_MAGNITUDE);
    202:       }
    203:       NEPSetTarget(nep,s);
    204:     }

    206:     PetscOptionsBool("-nep_two_sided","Use two-sided variant (to compute left eigenvectors)","NEPSetTwoSided",nep->twosided,&bval,&flg);
    207:     if (flg) { NEPSetTwoSided(nep,bval); }

    209:     /* -----------------------------------------------------------------------*/
    210:     /*
    211:       Cancels all monitors hardwired into code before call to NEPSetFromOptions()
    212:     */
    213:     PetscOptionsBool("-nep_monitor_cancel","Remove any hardwired monitor routines","NEPMonitorCancel",PETSC_FALSE,&flg,&set);
    214:     if (set && flg) {
    215:       NEPMonitorCancel(nep);
    216:     }
    217:     /*
    218:       Text monitors
    219:     */
    220:     NEPMonitorSetFromOptions(nep,"-nep_monitor","Monitor first unconverged approximate eigenvalue and error estimate","NEPMonitorFirst",NEPMonitorFirst,PETSC_FALSE);
    221:     NEPConvMonitorSetFromOptions(nep,"-nep_monitor_conv","Monitor approximate eigenvalues and error estimates as they converge","NEPMonitorConverged",NEPMonitorConverged);
    222:     NEPMonitorSetFromOptions(nep,"-nep_monitor_all","Monitor approximate eigenvalues and error estimates","NEPMonitorAll",NEPMonitorAll,PETSC_TRUE);
    223:     /*
    224:       Line graph monitors
    225:     */
    226:     PetscOptionsBool("-nep_monitor_lg","Monitor first unconverged approximate error estimate graphically","NEPMonitorSet",PETSC_FALSE,&flg,&set);
    227:     if (set && flg) {
    228:       NEPMonitorLGCreate(PetscObjectComm((PetscObject)nep),NULL,"Error estimates",PETSC_DECIDE,PETSC_DECIDE,300,300,&lg);
    229:       NEPMonitorSet(nep,NEPMonitorLG,lg,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
    230:     }
    231:     PetscOptionsBool("-nep_monitor_lg_all","Monitor error estimates graphically","NEPMonitorSet",PETSC_FALSE,&flg,&set);
    232:     if (set && flg) {
    233:       NEPMonitorLGCreate(PetscObjectComm((PetscObject)nep),NULL,"Error estimates",PETSC_DECIDE,PETSC_DECIDE,300,300,&lg);
    234:       NEPMonitorSet(nep,NEPMonitorLGAll,lg,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
    235:       NEPSetTrackAll(nep,PETSC_TRUE);
    236:     }

    238:     /* -----------------------------------------------------------------------*/
    239:     PetscOptionsName("-nep_view","Print detailed information on solver used","NEPView",NULL);
    240:     PetscOptionsName("-nep_view_vectors","View computed eigenvectors","NEPVectorsView",NULL);
    241:     PetscOptionsName("-nep_view_values","View computed eigenvalues","NEPValuesView",NULL);
    242:     PetscOptionsName("-nep_converged_reason","Print reason for convergence, and number of iterations","NEPConvergedReasonView",NULL);
    243:     PetscOptionsName("-nep_error_absolute","Print absolute errors of each eigenpair","NEPErrorView",NULL);
    244:     PetscOptionsName("-nep_error_relative","Print relative errors of each eigenpair","NEPErrorView",NULL);

    246:     if (nep->ops->setfromoptions) {
    247:       (*nep->ops->setfromoptions)(PetscOptionsObject,nep);
    248:     }
    249:     PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)nep);
    250:   PetscOptionsEnd();

    252:   if (!nep->V) { NEPGetBV(nep,&nep->V); }
    253:   BVSetFromOptions(nep->V);
    254:   if (!nep->rg) { NEPGetRG(nep,&nep->rg); }
    255:   RGSetFromOptions(nep->rg);
    256:   if (nep->useds) {
    257:     if (!nep->ds) { NEPGetDS(nep,&nep->ds); }
    258:     DSSetFromOptions(nep->ds);
    259:   }
    260:   if (!nep->refineksp) { NEPRefineGetKSP(nep,&nep->refineksp); }
    261:   KSPSetFromOptions(nep->refineksp);
    262:   if (nep->fui==NEP_USER_INTERFACE_SPLIT) for (i=0;i<nep->nt;i++) {FNSetFromOptions(nep->f[i]);}
    263:   return(0);
    264: }

    266: /*@C
    267:    NEPGetTolerances - Gets the tolerance and maximum iteration count used
    268:    by the NEP convergence tests.

    270:    Not Collective

    272:    Input Parameter:
    273: .  nep - the nonlinear eigensolver context

    275:    Output Parameters:
    276: +  tol - the convergence tolerance
    277: -  maxits - maximum number of iterations

    279:    Notes:
    280:    The user can specify NULL for any parameter that is not needed.

    282:    Level: intermediate

    284: .seealso: NEPSetTolerances()
    285: @*/
    286: PetscErrorCode NEPGetTolerances(NEP nep,PetscReal *tol,PetscInt *maxits)
    287: {
    290:   if (tol)    *tol    = nep->tol;
    291:   if (maxits) *maxits = nep->max_it;
    292:   return(0);
    293: }

    295: /*@
    296:    NEPSetTolerances - Sets the tolerance and maximum iteration count used
    297:    by the NEP convergence tests.

    299:    Logically Collective on nep

    301:    Input Parameters:
    302: +  nep    - the nonlinear eigensolver context
    303: .  tol    - the convergence tolerance
    304: -  maxits - maximum number of iterations to use

    306:    Options Database Keys:
    307: +  -nep_tol <tol> - Sets the convergence tolerance
    308: -  -nep_max_it <maxits> - Sets the maximum number of iterations allowed

    310:    Notes:
    311:    Use PETSC_DEFAULT for either argument to assign a reasonably good value.

    313:    Level: intermediate

    315: .seealso: NEPGetTolerances()
    316: @*/
    317: PetscErrorCode NEPSetTolerances(NEP nep,PetscReal tol,PetscInt maxits)
    318: {
    323:   if (tol == PETSC_DEFAULT) {
    324:     nep->tol   = PETSC_DEFAULT;
    325:     nep->state = NEP_STATE_INITIAL;
    326:   } else {
    327:     if (tol <= 0.0) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    328:     nep->tol = tol;
    329:   }
    330:   if (maxits == PETSC_DEFAULT || maxits == PETSC_DECIDE) {
    331:     nep->max_it = PETSC_DEFAULT;
    332:     nep->state  = NEP_STATE_INITIAL;
    333:   } else {
    334:     if (maxits <= 0) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
    335:     nep->max_it = maxits;
    336:   }
    337:   return(0);
    338: }

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

    344:    Not Collective

    346:    Input Parameter:
    347: .  nep - the nonlinear eigensolver context

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

    354:    Notes:
    355:    The user can specify NULL for any parameter that is not needed.

    357:    Level: intermediate

    359: .seealso: NEPSetDimensions()
    360: @*/
    361: PetscErrorCode NEPGetDimensions(NEP nep,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
    362: {
    365:   if (nev) *nev = nep->nev;
    366:   if (ncv) *ncv = nep->ncv;
    367:   if (mpd) *mpd = nep->mpd;
    368:   return(0);
    369: }

    371: /*@
    372:    NEPSetDimensions - Sets the number of eigenvalues to compute
    373:    and the dimension of the subspace.

    375:    Logically Collective on nep

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

    383:    Options Database Keys:
    384: +  -nep_nev <nev> - Sets the number of eigenvalues
    385: .  -nep_ncv <ncv> - Sets the dimension of the subspace
    386: -  -nep_mpd <mpd> - Sets the maximum projected dimension

    388:    Notes:
    389:    Use PETSC_DEFAULT for ncv and mpd to assign a reasonably good value, which is
    390:    dependent on the solution method.

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

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

    401:    Level: intermediate

    403: .seealso: NEPGetDimensions()
    404: @*/
    405: PetscErrorCode NEPSetDimensions(NEP nep,PetscInt nev,PetscInt ncv,PetscInt mpd)
    406: {
    412:   if (nev<1) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
    413:   nep->nev = nev;
    414:   if (ncv == PETSC_DECIDE || ncv == PETSC_DEFAULT) {
    415:     nep->ncv = PETSC_DEFAULT;
    416:   } else {
    417:     if (ncv<1) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
    418:     nep->ncv = ncv;
    419:   }
    420:   if (mpd == PETSC_DECIDE || mpd == PETSC_DEFAULT) {
    421:     nep->mpd = PETSC_DEFAULT;
    422:   } else {
    423:     if (mpd<1) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
    424:     nep->mpd = mpd;
    425:   }
    426:   nep->state = NEP_STATE_INITIAL;
    427:   return(0);
    428: }

    430: /*@
    431:     NEPSetWhichEigenpairs - Specifies which portion of the spectrum is
    432:     to be sought.

    434:     Logically Collective on nep

    436:     Input Parameters:
    437: +   nep   - eigensolver context obtained from NEPCreate()
    438: -   which - the portion of the spectrum to be sought

    440:     Possible values:
    441:     The parameter 'which' can have one of these values

    443: +     NEP_LARGEST_MAGNITUDE - largest eigenvalues in magnitude (default)
    444: .     NEP_SMALLEST_MAGNITUDE - smallest eigenvalues in magnitude
    445: .     NEP_LARGEST_REAL - largest real parts
    446: .     NEP_SMALLEST_REAL - smallest real parts
    447: .     NEP_LARGEST_IMAGINARY - largest imaginary parts
    448: .     NEP_SMALLEST_IMAGINARY - smallest imaginary parts
    449: .     NEP_TARGET_MAGNITUDE - eigenvalues closest to the target (in magnitude)
    450: .     NEP_TARGET_REAL - eigenvalues with real part closest to target
    451: .     NEP_TARGET_IMAGINARY - eigenvalues with imaginary part closest to target
    452: .     NEP_ALL - all eigenvalues contained in a given region
    453: -     NEP_WHICH_USER - user defined ordering set with NEPSetEigenvalueComparison()

    455:     Options Database Keys:
    456: +   -nep_largest_magnitude - Sets largest eigenvalues in magnitude
    457: .   -nep_smallest_magnitude - Sets smallest eigenvalues in magnitude
    458: .   -nep_largest_real - Sets largest real parts
    459: .   -nep_smallest_real - Sets smallest real parts
    460: .   -nep_largest_imaginary - Sets largest imaginary parts
    461: .   -nep_smallest_imaginary - Sets smallest imaginary parts
    462: .   -nep_target_magnitude - Sets eigenvalues closest to target
    463: .   -nep_target_real - Sets real parts closest to target
    464: .   -nep_target_imaginary - Sets imaginary parts closest to target
    465: -   -nep_all - Sets all eigenvalues in a region

    467:     Notes:
    468:     Not all eigensolvers implemented in NEP account for all the possible values
    469:     stated above. If SLEPc is compiled for real numbers NEP_LARGEST_IMAGINARY
    470:     and NEP_SMALLEST_IMAGINARY use the absolute value of the imaginary part
    471:     for eigenvalue selection.

    473:     The target is a scalar value provided with NEPSetTarget().

    475:     Level: intermediate

    477: .seealso: NEPGetWhichEigenpairs(), NEPSetTarget(), NEPSetEigenvalueComparison(), NEPWhich
    478: @*/
    479: PetscErrorCode NEPSetWhichEigenpairs(NEP nep,NEPWhich which)
    480: {
    484:   switch (which) {
    485:     case NEP_LARGEST_MAGNITUDE:
    486:     case NEP_SMALLEST_MAGNITUDE:
    487:     case NEP_LARGEST_REAL:
    488:     case NEP_SMALLEST_REAL:
    489:     case NEP_LARGEST_IMAGINARY:
    490:     case NEP_SMALLEST_IMAGINARY:
    491:     case NEP_TARGET_MAGNITUDE:
    492:     case NEP_TARGET_REAL:
    493: #if defined(PETSC_USE_COMPLEX)
    494:     case NEP_TARGET_IMAGINARY:
    495: #endif
    496:     case NEP_ALL:
    497:     case NEP_WHICH_USER:
    498:       if (nep->which != which) {
    499:         nep->state = NEP_STATE_INITIAL;
    500:         nep->which = which;
    501:       }
    502:       break;
    503: #if !defined(PETSC_USE_COMPLEX)
    504:     case NEP_TARGET_IMAGINARY:
    505:       SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_SUP,"NEP_TARGET_IMAGINARY can be used only with complex scalars");
    506: #endif
    507:     default:
    508:       SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'which' value");
    509:   }
    510:   return(0);
    511: }

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

    517:     Not Collective

    519:     Input Parameter:
    520: .   nep - eigensolver context obtained from NEPCreate()

    522:     Output Parameter:
    523: .   which - the portion of the spectrum to be sought

    525:     Notes:
    526:     See NEPSetWhichEigenpairs() for possible values of 'which'.

    528:     Level: intermediate

    530: .seealso: NEPSetWhichEigenpairs(), NEPWhich
    531: @*/
    532: PetscErrorCode NEPGetWhichEigenpairs(NEP nep,NEPWhich *which)
    533: {
    537:   *which = nep->which;
    538:   return(0);
    539: }

    541: /*@C
    542:    NEPSetEigenvalueComparison - Specifies the eigenvalue comparison function
    543:    when NEPSetWhichEigenpairs() is set to NEP_WHICH_USER.

    545:    Logically Collective on nep

    547:    Input Parameters:
    548: +  nep  - eigensolver context obtained from NEPCreate()
    549: .  func - a pointer to the comparison function
    550: -  ctx  - a context pointer (the last parameter to the comparison function)

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

    555: +   ar     - real part of the 1st eigenvalue
    556: .   ai     - imaginary part of the 1st eigenvalue
    557: .   br     - real part of the 2nd eigenvalue
    558: .   bi     - imaginary part of the 2nd eigenvalue
    559: .   res    - result of comparison
    560: -   ctx    - optional context, as set by NEPSetEigenvalueComparison()

    562:    Note:
    563:    The returning parameter 'res' can be
    564: +  negative - if the 1st eigenvalue is preferred to the 2st one
    565: .  zero     - if both eigenvalues are equally preferred
    566: -  positive - if the 2st eigenvalue is preferred to the 1st one

    568:    Level: advanced

    570: .seealso: NEPSetWhichEigenpairs(), NEPWhich
    571: @*/
    572: PetscErrorCode NEPSetEigenvalueComparison(NEP nep,PetscErrorCode (*func)(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*),void* ctx)
    573: {
    576:   nep->sc->comparison    = func;
    577:   nep->sc->comparisonctx = ctx;
    578:   nep->which             = NEP_WHICH_USER;
    579:   return(0);
    580: }

    582: /*@
    583:    NEPSetProblemType - Specifies the type of the nonlinear eigenvalue problem.

    585:    Logically Collective on nep

    587:    Input Parameters:
    588: +  nep  - the nonlinear eigensolver context
    589: -  type - a known type of nonlinear eigenvalue problem

    591:    Options Database Keys:
    592: +  -nep_general - general problem with no particular structure
    593: -  -nep_rational - a rational eigenvalue problem defined in split form with all f_i rational

    595:    Notes:
    596:    Allowed values for the problem type are: general (NEP_GENERAL), and rational
    597:    (NEP_RATIONAL).

    599:    This function is used to provide a hint to the NEP solver to exploit certain
    600:    properties of the nonlinear eigenproblem. This hint may be used or not,
    601:    depending on the solver. By default, no particular structure is assumed.

    603:    Level: intermediate

    605: .seealso: NEPSetType(), NEPGetProblemType(), NEPProblemType
    606: @*/
    607: PetscErrorCode NEPSetProblemType(NEP nep,NEPProblemType type)
    608: {
    612:   if (type!=NEP_GENERAL && type!=NEP_RATIONAL) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_WRONG,"Unknown eigenvalue problem type");
    613:   if (type != nep->problem_type) {
    614:     nep->problem_type = type;
    615:     nep->state = NEP_STATE_INITIAL;
    616:   }
    617:   return(0);
    618: }

    620: /*@
    621:    NEPGetProblemType - Gets the problem type from the NEP object.

    623:    Not Collective

    625:    Input Parameter:
    626: .  nep - the nonlinear eigensolver context

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

    631:    Level: intermediate

    633: .seealso: NEPSetProblemType(), NEPProblemType
    634: @*/
    635: PetscErrorCode NEPGetProblemType(NEP nep,NEPProblemType *type)
    636: {
    640:   *type = nep->problem_type;
    641:   return(0);
    642: }

    644: /*@
    645:    NEPSetTwoSided - Sets the solver to use a two-sided variant so that left
    646:    eigenvectors are also computed.

    648:    Logically Collective on nep

    650:    Input Parameters:
    651: +  nep      - the eigensolver context
    652: -  twosided - whether the two-sided variant is to be used or not

    654:    Options Database Keys:
    655: .  -nep_two_sided <boolean> - Sets/resets the twosided flag

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

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

    665:    Level: advanced

    667: .seealso: NEPGetTwoSided(), NEPGetLeftEigenvector()
    668: @*/
    669: PetscErrorCode NEPSetTwoSided(NEP nep,PetscBool twosided)
    670: {
    674:   if (twosided!=nep->twosided) {
    675:     nep->twosided = twosided;
    676:     nep->state    = NEP_STATE_INITIAL;
    677:   }
    678:   return(0);
    679: }

    681: /*@
    682:    NEPGetTwoSided - Returns the flag indicating whether a two-sided variant
    683:    of the algorithm is being used or not.

    685:    Not Collective

    687:    Input Parameter:
    688: .  nep - the eigensolver context

    690:    Output Parameter:
    691: .  twosided - the returned flag

    693:    Level: advanced

    695: .seealso: NEPSetTwoSided()
    696: @*/
    697: PetscErrorCode NEPGetTwoSided(NEP nep,PetscBool *twosided)
    698: {
    702:   *twosided = nep->twosided;
    703:   return(0);
    704: }

    706: /*@C
    707:    NEPSetConvergenceTestFunction - Sets a function to compute the error estimate
    708:    used in the convergence test.

    710:    Logically Collective on nep

    712:    Input Parameters:
    713: +  nep     - nonlinear eigensolver context obtained from NEPCreate()
    714: .  func    - a pointer to the convergence test function
    715: .  ctx     - context for private data for the convergence routine (may be null)
    716: -  destroy - a routine for destroying the context (may be null)

    718:    Calling Sequence of func:
    719: $   func(NEP nep,PetscScalar eigr,PetscScalar eigi,PetscReal res,PetscReal *errest,void *ctx)

    721: +   nep    - nonlinear eigensolver context obtained from NEPCreate()
    722: .   eigr   - real part of the eigenvalue
    723: .   eigi   - imaginary part of the eigenvalue
    724: .   res    - residual norm associated to the eigenpair
    725: .   errest - (output) computed error estimate
    726: -   ctx    - optional context, as set by NEPSetConvergenceTestFunction()

    728:    Note:
    729:    If the error estimate returned by the convergence test function is less than
    730:    the tolerance, then the eigenvalue is accepted as converged.

    732:    Level: advanced

    734: .seealso: NEPSetConvergenceTest(), NEPSetTolerances()
    735: @*/
    736: PetscErrorCode NEPSetConvergenceTestFunction(NEP nep,PetscErrorCode (*func)(NEP,PetscScalar,PetscScalar,PetscReal,PetscReal*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    737: {

    742:   if (nep->convergeddestroy) {
    743:     (*nep->convergeddestroy)(nep->convergedctx);
    744:   }
    745:   nep->convergeduser    = func;
    746:   nep->convergeddestroy = destroy;
    747:   nep->convergedctx     = ctx;
    748:   if (func == NEPConvergedRelative) nep->conv = NEP_CONV_REL;
    749:   else if (func == NEPConvergedNorm) nep->conv = NEP_CONV_NORM;
    750:   else if (func == NEPConvergedAbsolute) nep->conv = NEP_CONV_ABS;
    751:   else {
    752:     nep->conv      = NEP_CONV_USER;
    753:     nep->converged = nep->convergeduser;
    754:   }
    755:   return(0);
    756: }

    758: /*@
    759:    NEPSetConvergenceTest - Specifies how to compute the error estimate
    760:    used in the convergence test.

    762:    Logically Collective on nep

    764:    Input Parameters:
    765: +  nep  - nonlinear eigensolver context obtained from NEPCreate()
    766: -  conv - the type of convergence test

    768:    Options Database Keys:
    769: +  -nep_conv_abs  - Sets the absolute convergence test
    770: .  -nep_conv_rel  - Sets the convergence test relative to the eigenvalue
    771: -  -nep_conv_user - Selects the user-defined convergence test

    773:    Note:
    774:    The parameter 'conv' can have one of these values
    775: +     NEP_CONV_ABS  - absolute error ||r||
    776: .     NEP_CONV_REL  - error relative to the eigenvalue l, ||r||/|l|
    777: .     NEP_CONV_NORM - error relative matrix norms, ||r||/sum_i(|f_i(l)|*||A_i||)
    778: -     NEP_CONV_USER - function set by NEPSetConvergenceTestFunction()

    780:    Level: intermediate

    782: .seealso: NEPGetConvergenceTest(), NEPSetConvergenceTestFunction(), NEPSetStoppingTest(), NEPConv
    783: @*/
    784: PetscErrorCode NEPSetConvergenceTest(NEP nep,NEPConv conv)
    785: {
    789:   switch (conv) {
    790:     case NEP_CONV_ABS:  nep->converged = NEPConvergedAbsolute; break;
    791:     case NEP_CONV_REL:  nep->converged = NEPConvergedRelative; break;
    792:     case NEP_CONV_NORM: nep->converged = NEPConvergedNorm; break;
    793:     case NEP_CONV_USER:
    794:       if (!nep->convergeduser) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ORDER,"Must call NEPSetConvergenceTestFunction() first");
    795:       nep->converged = nep->convergeduser;
    796:       break;
    797:     default:
    798:       SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'conv' value");
    799:   }
    800:   nep->conv = conv;
    801:   return(0);
    802: }

    804: /*@
    805:    NEPGetConvergenceTest - Gets the method used to compute the error estimate
    806:    used in the convergence test.

    808:    Not Collective

    810:    Input Parameters:
    811: .  nep   - nonlinear eigensolver context obtained from NEPCreate()

    813:    Output Parameters:
    814: .  conv  - the type of convergence test

    816:    Level: intermediate

    818: .seealso: NEPSetConvergenceTest(), NEPConv
    819: @*/
    820: PetscErrorCode NEPGetConvergenceTest(NEP nep,NEPConv *conv)
    821: {
    825:   *conv = nep->conv;
    826:   return(0);
    827: }

    829: /*@C
    830:    NEPSetStoppingTestFunction - Sets a function to decide when to stop the outer
    831:    iteration of the eigensolver.

    833:    Logically Collective on nep

    835:    Input Parameters:
    836: +  nep     - nonlinear eigensolver context obtained from NEPCreate()
    837: .  func    - pointer to the stopping test function
    838: .  ctx     - context for private data for the stopping routine (may be null)
    839: -  destroy - a routine for destroying the context (may be null)

    841:    Calling Sequence of func:
    842: $   func(NEP nep,PetscInt its,PetscInt max_it,PetscInt nconv,PetscInt nev,NEPConvergedReason *reason,void *ctx)

    844: +   nep    - nonlinear eigensolver context obtained from NEPCreate()
    845: .   its    - current number of iterations
    846: .   max_it - maximum number of iterations
    847: .   nconv  - number of currently converged eigenpairs
    848: .   nev    - number of requested eigenpairs
    849: .   reason - (output) result of the stopping test
    850: -   ctx    - optional context, as set by NEPSetStoppingTestFunction()

    852:    Note:
    853:    Normal usage is to first call the default routine NEPStoppingBasic() and then
    854:    set reason to NEP_CONVERGED_USER if some user-defined conditions have been
    855:    met. To let the eigensolver continue iterating, the result must be left as
    856:    NEP_CONVERGED_ITERATING.

    858:    Level: advanced

    860: .seealso: NEPSetStoppingTest(), NEPStoppingBasic()
    861: @*/
    862: PetscErrorCode NEPSetStoppingTestFunction(NEP nep,PetscErrorCode (*func)(NEP,PetscInt,PetscInt,PetscInt,PetscInt,NEPConvergedReason*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    863: {

    868:   if (nep->stoppingdestroy) {
    869:     (*nep->stoppingdestroy)(nep->stoppingctx);
    870:   }
    871:   nep->stoppinguser    = func;
    872:   nep->stoppingdestroy = destroy;
    873:   nep->stoppingctx     = ctx;
    874:   if (func == NEPStoppingBasic) nep->stop = NEP_STOP_BASIC;
    875:   else {
    876:     nep->stop     = NEP_STOP_USER;
    877:     nep->stopping = nep->stoppinguser;
    878:   }
    879:   return(0);
    880: }

    882: /*@
    883:    NEPSetStoppingTest - Specifies how to decide the termination of the outer
    884:    loop of the eigensolver.

    886:    Logically Collective on nep

    888:    Input Parameters:
    889: +  nep  - nonlinear eigensolver context obtained from NEPCreate()
    890: -  stop - the type of stopping test

    892:    Options Database Keys:
    893: +  -nep_stop_basic - Sets the default stopping test
    894: -  -nep_stop_user  - Selects the user-defined stopping test

    896:    Note:
    897:    The parameter 'stop' can have one of these values
    898: +     NEP_STOP_BASIC - default stopping test
    899: -     NEP_STOP_USER  - function set by NEPSetStoppingTestFunction()

    901:    Level: advanced

    903: .seealso: NEPGetStoppingTest(), NEPSetStoppingTestFunction(), NEPSetConvergenceTest(), NEPStop
    904: @*/
    905: PetscErrorCode NEPSetStoppingTest(NEP nep,NEPStop stop)
    906: {
    910:   switch (stop) {
    911:     case NEP_STOP_BASIC: nep->stopping = NEPStoppingBasic; break;
    912:     case NEP_STOP_USER:
    913:       if (!nep->stoppinguser) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ORDER,"Must call NEPSetStoppingTestFunction() first");
    914:       nep->stopping = nep->stoppinguser;
    915:       break;
    916:     default:
    917:       SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'stop' value");
    918:   }
    919:   nep->stop = stop;
    920:   return(0);
    921: }

    923: /*@
    924:    NEPGetStoppingTest - Gets the method used to decide the termination of the outer
    925:    loop of the eigensolver.

    927:    Not Collective

    929:    Input Parameters:
    930: .  nep   - nonlinear eigensolver context obtained from NEPCreate()

    932:    Output Parameters:
    933: .  stop  - the type of stopping test

    935:    Level: advanced

    937: .seealso: NEPSetStoppingTest(), NEPStop
    938: @*/
    939: PetscErrorCode NEPGetStoppingTest(NEP nep,NEPStop *stop)
    940: {
    944:   *stop = nep->stop;
    945:   return(0);
    946: }

    948: /*@
    949:    NEPSetTrackAll - Specifies if the solver must compute the residual of all
    950:    approximate eigenpairs or not.

    952:    Logically Collective on nep

    954:    Input Parameters:
    955: +  nep      - the eigensolver context
    956: -  trackall - whether compute all residuals or not

    958:    Notes:
    959:    If the user sets trackall=PETSC_TRUE then the solver explicitly computes
    960:    the residual for each eigenpair approximation. Computing the residual is
    961:    usually an expensive operation and solvers commonly compute the associated
    962:    residual to the first unconverged eigenpair.
    963:    The options '-nep_monitor_all' and '-nep_monitor_lg_all' automatically
    964:    activate this option.

    966:    Level: developer

    968: .seealso: NEPGetTrackAll()
    969: @*/
    970: PetscErrorCode NEPSetTrackAll(NEP nep,PetscBool trackall)
    971: {
    975:   nep->trackall = trackall;
    976:   return(0);
    977: }

    979: /*@
    980:    NEPGetTrackAll - Returns the flag indicating whether all residual norms must
    981:    be computed or not.

    983:    Not Collective

    985:    Input Parameter:
    986: .  nep - the eigensolver context

    988:    Output Parameter:
    989: .  trackall - the returned flag

    991:    Level: developer

    993: .seealso: NEPSetTrackAll()
    994: @*/
    995: PetscErrorCode NEPGetTrackAll(NEP nep,PetscBool *trackall)
    996: {
    1000:   *trackall = nep->trackall;
    1001:   return(0);
    1002: }

    1004: /*@
    1005:    NEPSetRefine - Specifies the refinement type (and options) to be used
    1006:    after the solve.

    1008:    Logically Collective on nep

    1010:    Input Parameters:
    1011: +  nep    - the nonlinear eigensolver context
    1012: .  refine - refinement type
    1013: .  npart  - number of partitions of the communicator
    1014: .  tol    - the convergence tolerance
    1015: .  its    - maximum number of refinement iterations
    1016: -  scheme - which scheme to be used for solving the involved linear systems

    1018:    Options Database Keys:
    1019: +  -nep_refine <type> - refinement type, one of <none,simple,multiple>
    1020: .  -nep_refine_partitions <n> - the number of partitions
    1021: .  -nep_refine_tol <tol> - the tolerance
    1022: .  -nep_refine_its <its> - number of iterations
    1023: -  -nep_refine_scheme - to set the scheme for the linear solves

    1025:    Notes:
    1026:    By default, iterative refinement is disabled, since it may be very
    1027:    costly. There are two possible refinement strategies: simple and multiple.
    1028:    The simple approach performs iterative refinement on each of the
    1029:    converged eigenpairs individually, whereas the multiple strategy works
    1030:    with the invariant pair as a whole, refining all eigenpairs simultaneously.
    1031:    The latter may be required for the case of multiple eigenvalues.

    1033:    In some cases, especially when using direct solvers within the
    1034:    iterative refinement method, it may be helpful for improved scalability
    1035:    to split the communicator in several partitions. The npart parameter
    1036:    indicates how many partitions to use (defaults to 1).

    1038:    The tol and its parameters specify the stopping criterion. In the simple
    1039:    method, refinement continues until the residual of each eigenpair is
    1040:    below the tolerance (tol defaults to the NEP tol, but may be set to a
    1041:    different value). In contrast, the multiple method simply performs its
    1042:    refinement iterations (just one by default).

    1044:    The scheme argument is used to change the way in which linear systems are
    1045:    solved. Possible choices are: explicit, mixed block elimination (MBE),
    1046:    and Schur complement.

    1048:    Level: intermediate

    1050: .seealso: NEPGetRefine()
    1051: @*/
    1052: PetscErrorCode NEPSetRefine(NEP nep,NEPRefine refine,PetscInt npart,PetscReal tol,PetscInt its,NEPRefineScheme scheme)
    1053: {
    1055:   PetscMPIInt    size;

    1064:   nep->refine = refine;
    1065:   if (refine) {  /* process parameters only if not REFINE_NONE */
    1066:     if (npart!=nep->npart) {
    1067:       PetscSubcommDestroy(&nep->refinesubc);
    1068:       KSPDestroy(&nep->refineksp);
    1069:     }
    1070:     if (npart == PETSC_DEFAULT || npart == PETSC_DECIDE) {
    1071:       nep->npart = 1;
    1072:     } else {
    1073:       MPI_Comm_size(PetscObjectComm((PetscObject)nep),&size);
    1074:       if (npart<1 || npart>size) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of npart");
    1075:       nep->npart = npart;
    1076:     }
    1077:     if (tol == PETSC_DEFAULT || tol == PETSC_DECIDE) {
    1078:       nep->rtol = PETSC_DEFAULT;
    1079:     } else {
    1080:       if (tol<=0.0) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    1081:       nep->rtol = tol;
    1082:     }
    1083:     if (its==PETSC_DECIDE || its==PETSC_DEFAULT) {
    1084:       nep->rits = PETSC_DEFAULT;
    1085:     } else {
    1086:       if (its<0) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be >= 0");
    1087:       nep->rits = its;
    1088:     }
    1089:     nep->scheme = scheme;
    1090:   }
    1091:   nep->state = NEP_STATE_INITIAL;
    1092:   return(0);
    1093: }

    1095: /*@C
    1096:    NEPGetRefine - Gets the refinement strategy used by the NEP object, and the
    1097:    associated parameters.

    1099:    Not Collective

    1101:    Input Parameter:
    1102: .  nep - the nonlinear eigensolver context

    1104:    Output Parameters:
    1105: +  refine - refinement type
    1106: .  npart  - number of partitions of the communicator
    1107: .  tol    - the convergence tolerance
    1108: -  its    - maximum number of refinement iterations
    1109: -  scheme - the scheme used for solving linear systems

    1111:    Level: intermediate

    1113:    Note:
    1114:    The user can specify NULL for any parameter that is not needed.

    1116: .seealso: NEPSetRefine()
    1117: @*/
    1118: PetscErrorCode NEPGetRefine(NEP nep,NEPRefine *refine,PetscInt *npart,PetscReal *tol,PetscInt *its,NEPRefineScheme *scheme)
    1119: {
    1122:   if (refine) *refine = nep->refine;
    1123:   if (npart)  *npart  = nep->npart;
    1124:   if (tol)    *tol    = nep->rtol;
    1125:   if (its)    *its    = nep->rits;
    1126:   if (scheme) *scheme = nep->scheme;
    1127:   return(0);
    1128: }

    1130: /*@C
    1131:    NEPSetOptionsPrefix - Sets the prefix used for searching for all
    1132:    NEP options in the database.

    1134:    Logically Collective on nep

    1136:    Input Parameters:
    1137: +  nep - the nonlinear eigensolver context
    1138: -  prefix - the prefix string to prepend to all NEP option requests

    1140:    Notes:
    1141:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1142:    The first character of all runtime options is AUTOMATICALLY the
    1143:    hyphen.

    1145:    For example, to distinguish between the runtime options for two
    1146:    different NEP contexts, one could call
    1147: .vb
    1148:       NEPSetOptionsPrefix(nep1,"neig1_")
    1149:       NEPSetOptionsPrefix(nep2,"neig2_")
    1150: .ve

    1152:    Level: advanced

    1154: .seealso: NEPAppendOptionsPrefix(), NEPGetOptionsPrefix()
    1155: @*/
    1156: PetscErrorCode NEPSetOptionsPrefix(NEP nep,const char *prefix)
    1157: {

    1162:   if (!nep->V) { NEPGetBV(nep,&nep->V); }
    1163:   BVSetOptionsPrefix(nep->V,prefix);
    1164:   if (!nep->ds) { NEPGetDS(nep,&nep->ds); }
    1165:   DSSetOptionsPrefix(nep->ds,prefix);
    1166:   if (!nep->rg) { NEPGetRG(nep,&nep->rg); }
    1167:   RGSetOptionsPrefix(nep->rg,prefix);
    1168:   PetscObjectSetOptionsPrefix((PetscObject)nep,prefix);
    1169:   return(0);
    1170: }

    1172: /*@C
    1173:    NEPAppendOptionsPrefix - Appends to the prefix used for searching for all
    1174:    NEP options in the database.

    1176:    Logically Collective on nep

    1178:    Input Parameters:
    1179: +  nep - the nonlinear eigensolver context
    1180: -  prefix - the prefix string to prepend to all NEP option requests

    1182:    Notes:
    1183:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1184:    The first character of all runtime options is AUTOMATICALLY the hyphen.

    1186:    Level: advanced

    1188: .seealso: NEPSetOptionsPrefix(), NEPGetOptionsPrefix()
    1189: @*/
    1190: PetscErrorCode NEPAppendOptionsPrefix(NEP nep,const char *prefix)
    1191: {

    1196:   if (!nep->V) { NEPGetBV(nep,&nep->V); }
    1197:   BVAppendOptionsPrefix(nep->V,prefix);
    1198:   if (!nep->ds) { NEPGetDS(nep,&nep->ds); }
    1199:   DSAppendOptionsPrefix(nep->ds,prefix);
    1200:   if (!nep->rg) { NEPGetRG(nep,&nep->rg); }
    1201:   RGAppendOptionsPrefix(nep->rg,prefix);
    1202:   PetscObjectAppendOptionsPrefix((PetscObject)nep,prefix);
    1203:   return(0);
    1204: }

    1206: /*@C
    1207:    NEPGetOptionsPrefix - Gets the prefix used for searching for all
    1208:    NEP options in the database.

    1210:    Not Collective

    1212:    Input Parameters:
    1213: .  nep - the nonlinear eigensolver context

    1215:    Output Parameters:
    1216: .  prefix - pointer to the prefix string used is returned

    1218:    Note:
    1219:    On the Fortran side, the user should pass in a string 'prefix' of
    1220:    sufficient length to hold the prefix.

    1222:    Level: advanced

    1224: .seealso: NEPSetOptionsPrefix(), NEPAppendOptionsPrefix()
    1225: @*/
    1226: PetscErrorCode NEPGetOptionsPrefix(NEP nep,const char *prefix[])
    1227: {

    1233:   PetscObjectGetOptionsPrefix((PetscObject)nep,prefix);
    1234:   return(0);
    1235: }