Actual source code: nepopts.c
slepc-3.10.1 2018-10-23
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2018, 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>       /*I "slepcnep.h" I*/
     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)->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)->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;
    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,256,&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? nep->max_it: PETSC_DEFAULT;
    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? nep->ncv: PETSC_DEFAULT;
    170:     PetscOptionsInt("-nep_ncv","Number of basis vectors","NEPSetDimensions",nep->ncv,&j,&flg2);
    171:     k = nep->mpd? nep->mpd: PETSC_DEFAULT;
    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:     /* -----------------------------------------------------------------------*/
    207:     /*
    208:       Cancels all monitors hardwired into code before call to NEPSetFromOptions()
    209:     */
    210:     PetscOptionsBool("-nep_monitor_cancel","Remove any hardwired monitor routines","NEPMonitorCancel",PETSC_FALSE,&flg,&set);
    211:     if (set && flg) {
    212:       NEPMonitorCancel(nep);
    213:     }
    214:     /*
    215:       Text monitors
    216:     */
    217:     NEPMonitorSetFromOptions(nep,"-nep_monitor","Monitor first unconverged approximate eigenvalue and error estimate","NEPMonitorFirst",NEPMonitorFirst,PETSC_FALSE);
    218:     NEPConvMonitorSetFromOptions(nep,"-nep_monitor_conv","Monitor approximate eigenvalues and error estimates as they converge","NEPMonitorConverged",NEPMonitorConverged);
    219:     NEPMonitorSetFromOptions(nep,"-nep_monitor_all","Monitor approximate eigenvalues and error estimates","NEPMonitorAll",NEPMonitorAll,PETSC_TRUE);
    220:     /*
    221:       Line graph monitors
    222:     */
    223:     PetscOptionsBool("-nep_monitor_lg","Monitor first unconverged approximate error estimate graphically","NEPMonitorSet",PETSC_FALSE,&flg,&set);
    224:     if (set && flg) {
    225:       NEPMonitorLGCreate(PetscObjectComm((PetscObject)nep),NULL,"Error estimates",PETSC_DECIDE,PETSC_DECIDE,300,300,&lg);
    226:       NEPMonitorSet(nep,NEPMonitorLG,lg,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
    227:     }
    228:     PetscOptionsBool("-nep_monitor_lg_all","Monitor error estimates graphically","NEPMonitorSet",PETSC_FALSE,&flg,&set);
    229:     if (set && flg) {
    230:       NEPMonitorLGCreate(PetscObjectComm((PetscObject)nep),NULL,"Error estimates",PETSC_DECIDE,PETSC_DECIDE,300,300,&lg);
    231:       NEPMonitorSet(nep,NEPMonitorLGAll,lg,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
    232:       NEPSetTrackAll(nep,PETSC_TRUE);
    233:     }

    235:     /* -----------------------------------------------------------------------*/
    236:     PetscOptionsName("-nep_view","Print detailed information on solver used","NEPView",NULL);
    237:     PetscOptionsName("-nep_view_vectors","View computed eigenvectors","NEPVectorsView",NULL);
    238:     PetscOptionsName("-nep_view_values","View computed eigenvalues","NEPValuesView",NULL);
    239:     PetscOptionsName("-nep_converged_reason","Print reason for convergence, and number of iterations","NEPReasonView",NULL);
    240:     PetscOptionsName("-nep_error_absolute","Print absolute errors of each eigenpair","NEPErrorView",NULL);
    241:     PetscOptionsName("-nep_error_relative","Print relative errors of each eigenpair","NEPErrorView",NULL);

    243:     if (nep->ops->setfromoptions) {
    244:       (*nep->ops->setfromoptions)(PetscOptionsObject,nep);
    245:     }
    246:     PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)nep);
    247:   PetscOptionsEnd();

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

    261: /*@C
    262:    NEPGetTolerances - Gets the tolerance and maximum iteration count used
    263:    by the NEP convergence tests.

    265:    Not Collective

    267:    Input Parameter:
    268: .  nep - the nonlinear eigensolver context

    270:    Output Parameters:
    271: +  tol - the convergence tolerance
    272: -  maxits - maximum number of iterations

    274:    Notes:
    275:    The user can specify NULL for any parameter that is not needed.

    277:    Level: intermediate

    279: .seealso: NEPSetTolerances()
    280: @*/
    281: PetscErrorCode NEPGetTolerances(NEP nep,PetscReal *tol,PetscInt *maxits)
    282: {
    285:   if (tol)    *tol    = nep->tol;
    286:   if (maxits) *maxits = nep->max_it;
    287:   return(0);
    288: }

    290: /*@
    291:    NEPSetTolerances - Sets the tolerance and maximum iteration count used
    292:    by the NEP convergence tests.

    294:    Logically Collective on NEP

    296:    Input Parameters:
    297: +  nep    - the nonlinear eigensolver context
    298: .  tol    - the convergence tolerance
    299: -  maxits - maximum number of iterations to use

    301:    Options Database Keys:
    302: +  -nep_tol <tol> - Sets the convergence tolerance
    303: -  -nep_max_it <maxits> - Sets the maximum number of iterations allowed

    305:    Notes:
    306:    Use PETSC_DEFAULT for either argument to assign a reasonably good value.

    308:    Level: intermediate

    310: .seealso: NEPGetTolerances()
    311: @*/
    312: PetscErrorCode NEPSetTolerances(NEP nep,PetscReal tol,PetscInt maxits)
    313: {
    318:   if (tol == PETSC_DEFAULT) {
    319:     nep->tol   = PETSC_DEFAULT;
    320:     nep->state = NEP_STATE_INITIAL;
    321:   } else {
    322:     if (tol <= 0.0) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    323:     nep->tol = tol;
    324:   }
    325:   if (maxits == PETSC_DEFAULT || maxits == PETSC_DECIDE) {
    326:     nep->max_it = 0;
    327:     nep->state  = NEP_STATE_INITIAL;
    328:   } else {
    329:     if (maxits <= 0) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
    330:     nep->max_it = maxits;
    331:   }
    332:   return(0);
    333: }

    335: /*@C
    336:    NEPGetDimensions - Gets the number of eigenvalues to compute
    337:    and the dimension of the subspace.

    339:    Not Collective

    341:    Input Parameter:
    342: .  nep - the nonlinear eigensolver context

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

    349:    Notes:
    350:    The user can specify NULL for any parameter that is not needed.

    352:    Level: intermediate

    354: .seealso: NEPSetDimensions()
    355: @*/
    356: PetscErrorCode NEPGetDimensions(NEP nep,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
    357: {
    360:   if (nev) *nev = nep->nev;
    361:   if (ncv) *ncv = nep->ncv;
    362:   if (mpd) *mpd = nep->mpd;
    363:   return(0);
    364: }

    366: /*@
    367:    NEPSetDimensions - Sets the number of eigenvalues to compute
    368:    and the dimension of the subspace.

    370:    Logically Collective on NEP

    372:    Input Parameters:
    373: +  nep - the nonlinear eigensolver context
    374: .  nev - number of eigenvalues to compute
    375: .  ncv - the maximum dimension of the subspace to be used by the solver
    376: -  mpd - the maximum dimension allowed for the projected problem

    378:    Options Database Keys:
    379: +  -nep_nev <nev> - Sets the number of eigenvalues
    380: .  -nep_ncv <ncv> - Sets the dimension of the subspace
    381: -  -nep_mpd <mpd> - Sets the maximum projected dimension

    383:    Notes:
    384:    Use PETSC_DEFAULT for ncv and mpd to assign a reasonably good value, which is
    385:    dependent on the solution method.

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

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

    396:    Level: intermediate

    398: .seealso: NEPGetDimensions()
    399: @*/
    400: PetscErrorCode NEPSetDimensions(NEP nep,PetscInt nev,PetscInt ncv,PetscInt mpd)
    401: {
    407:   if (nev<1) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
    408:   nep->nev = nev;
    409:   if (ncv == PETSC_DECIDE || ncv == PETSC_DEFAULT) {
    410:     nep->ncv = 0;
    411:   } else {
    412:     if (ncv<1) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
    413:     nep->ncv = ncv;
    414:   }
    415:   if (mpd == PETSC_DECIDE || mpd == PETSC_DEFAULT) {
    416:     nep->mpd = 0;
    417:   } else {
    418:     if (mpd<1) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
    419:     nep->mpd = mpd;
    420:   }
    421:   nep->state = NEP_STATE_INITIAL;
    422:   return(0);
    423: }

    425: /*@
    426:     NEPSetWhichEigenpairs - Specifies which portion of the spectrum is
    427:     to be sought.

    429:     Logically Collective on NEP

    431:     Input Parameters:
    432: +   nep   - eigensolver context obtained from NEPCreate()
    433: -   which - the portion of the spectrum to be sought

    435:     Possible values:
    436:     The parameter 'which' can have one of these values

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

    450:     Options Database Keys:
    451: +   -nep_largest_magnitude - Sets largest eigenvalues in magnitude
    452: .   -nep_smallest_magnitude - Sets smallest eigenvalues in magnitude
    453: .   -nep_largest_real - Sets largest real parts
    454: .   -nep_smallest_real - Sets smallest real parts
    455: .   -nep_largest_imaginary - Sets largest imaginary parts
    456: .   -nep_smallest_imaginary - Sets smallest imaginary parts
    457: .   -nep_target_magnitude - Sets eigenvalues closest to target
    458: .   -nep_target_real - Sets real parts closest to target
    459: .   -nep_target_imaginary - Sets imaginary parts closest to target
    460: -   -nep_all - Sets all eigenvalues in a region

    462:     Notes:
    463:     Not all eigensolvers implemented in NEP account for all the possible values
    464:     stated above. If SLEPc is compiled for real numbers NEP_LARGEST_IMAGINARY
    465:     and NEP_SMALLEST_IMAGINARY use the absolute value of the imaginary part
    466:     for eigenvalue selection.

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

    470:     NEP_ALL is intended for use in the context of the CISS solver for
    471:     computing all eigenvalues in a region.

    473:     Level: intermediate

    475: .seealso: NEPGetWhichEigenpairs(), NEPSetTarget(), NEPSetEigenvalueComparison(), NEPWhich
    476: @*/
    477: PetscErrorCode NEPSetWhichEigenpairs(NEP nep,NEPWhich which)
    478: {
    482:   switch (which) {
    483:     case NEP_LARGEST_MAGNITUDE:
    484:     case NEP_SMALLEST_MAGNITUDE:
    485:     case NEP_LARGEST_REAL:
    486:     case NEP_SMALLEST_REAL:
    487:     case NEP_LARGEST_IMAGINARY:
    488:     case NEP_SMALLEST_IMAGINARY:
    489:     case NEP_TARGET_MAGNITUDE:
    490:     case NEP_TARGET_REAL:
    491: #if defined(PETSC_USE_COMPLEX)
    492:     case NEP_TARGET_IMAGINARY:
    493: #endif
    494:     case EPS_ALL:
    495:     case NEP_WHICH_USER:
    496:       if (nep->which != which) {
    497:         nep->state = NEP_STATE_INITIAL;
    498:         nep->which = which;
    499:       }
    500:       break;
    501:     default:
    502:       SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'which' value");
    503:   }
    504:   return(0);
    505: }

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

    511:     Not Collective

    513:     Input Parameter:
    514: .   nep - eigensolver context obtained from NEPCreate()

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

    519:     Notes:
    520:     See NEPSetWhichEigenpairs() for possible values of 'which'.

    522:     Level: intermediate

    524: .seealso: NEPSetWhichEigenpairs(), NEPWhich
    525: @*/
    526: PetscErrorCode NEPGetWhichEigenpairs(NEP nep,NEPWhich *which)
    527: {
    531:   *which = nep->which;
    532:   return(0);
    533: }

    535: /*@C
    536:    NEPSetEigenvalueComparison - Specifies the eigenvalue comparison function
    537:    when NEPSetWhichEigenpairs() is set to NEP_WHICH_USER.

    539:    Logically Collective on NEP

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

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

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

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

    562:    Level: advanced

    564: .seealso: NEPSetWhichEigenpairs(), NEPWhich
    565: @*/
    566: PetscErrorCode NEPSetEigenvalueComparison(NEP nep,PetscErrorCode (*func)(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*),void* ctx)
    567: {
    570:   nep->sc->comparison    = func;
    571:   nep->sc->comparisonctx = ctx;
    572:   nep->which             = NEP_WHICH_USER;
    573:   return(0);
    574: }

    576: /*@
    577:    NEPSetProblemType - Specifies the type of the nonlinear eigenvalue problem.

    579:    Logically Collective on NEP

    581:    Input Parameters:
    582: +  nep  - the nonlinear eigensolver context
    583: -  type - a known type of nonlinear eigenvalue problem

    585:    Options Database Keys:
    586: +  -nep_general - general problem with no particular structure
    587: -  -nep_rational - a rational eigenvalue problem defined in split form with all f_i rational

    589:    Notes:
    590:    Allowed values for the problem type are: general (NEP_GENERAL), and rational
    591:    (NEP_RATIONAL).

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

    597:    Level: intermediate

    599: .seealso: NEPSetType(), NEPGetProblemType(), NEPProblemType
    600: @*/
    601: PetscErrorCode NEPSetProblemType(NEP nep,NEPProblemType type)
    602: {
    606:   if (type!=NEP_GENERAL && type!=NEP_RATIONAL) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_WRONG,"Unknown eigenvalue problem type");
    607:   if (type != nep->problem_type) {
    608:     nep->problem_type = type;
    609:     nep->state = NEP_STATE_INITIAL;
    610:   }
    611:   return(0);
    612: }

    614: /*@
    615:    NEPGetProblemType - Gets the problem type from the NEP object.

    617:    Not Collective

    619:    Input Parameter:
    620: .  nep - the nonlinear eigensolver context

    622:    Output Parameter:
    623: .  type - the problem type

    625:    Level: intermediate

    627: .seealso: NEPSetProblemType(), NEPProblemType
    628: @*/
    629: PetscErrorCode NEPGetProblemType(NEP nep,NEPProblemType *type)
    630: {
    634:   *type = nep->problem_type;
    635:   return(0);
    636: }

    638: /*@C
    639:    NEPSetConvergenceTestFunction - Sets a function to compute the error estimate
    640:    used in the convergence test.

    642:    Logically Collective on NEP

    644:    Input Parameters:
    645: +  nep     - nonlinear eigensolver context obtained from NEPCreate()
    646: .  func    - a pointer to the convergence test function
    647: .  ctx     - context for private data for the convergence routine (may be null)
    648: -  destroy - a routine for destroying the context (may be null)

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

    653: +   nep    - nonlinear eigensolver context obtained from NEPCreate()
    654: .   eigr   - real part of the eigenvalue
    655: .   eigi   - imaginary part of the eigenvalue
    656: .   res    - residual norm associated to the eigenpair
    657: .   errest - (output) computed error estimate
    658: -   ctx    - optional context, as set by NEPSetConvergenceTestFunction()

    660:    Note:
    661:    If the error estimate returned by the convergence test function is less than
    662:    the tolerance, then the eigenvalue is accepted as converged.

    664:    Level: advanced

    666: .seealso: NEPSetConvergenceTest(), NEPSetTolerances()
    667: @*/
    668: PetscErrorCode NEPSetConvergenceTestFunction(NEP nep,PetscErrorCode (*func)(NEP,PetscScalar,PetscScalar,PetscReal,PetscReal*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    669: {

    674:   if (nep->convergeddestroy) {
    675:     (*nep->convergeddestroy)(nep->convergedctx);
    676:   }
    677:   nep->convergeduser    = func;
    678:   nep->convergeddestroy = destroy;
    679:   nep->convergedctx     = ctx;
    680:   if (func == NEPConvergedRelative) nep->conv = NEP_CONV_REL;
    681:   else if (func == NEPConvergedNorm) nep->conv = NEP_CONV_NORM;
    682:   else if (func == NEPConvergedAbsolute) nep->conv = NEP_CONV_ABS;
    683:   else {
    684:     nep->conv      = NEP_CONV_USER;
    685:     nep->converged = nep->convergeduser;
    686:   }
    687:   return(0);
    688: }

    690: /*@
    691:    NEPSetConvergenceTest - Specifies how to compute the error estimate
    692:    used in the convergence test.

    694:    Logically Collective on NEP

    696:    Input Parameters:
    697: +  nep  - nonlinear eigensolver context obtained from NEPCreate()
    698: -  conv - the type of convergence test

    700:    Options Database Keys:
    701: +  -nep_conv_abs  - Sets the absolute convergence test
    702: .  -nep_conv_rel  - Sets the convergence test relative to the eigenvalue
    703: -  -nep_conv_user - Selects the user-defined convergence test

    705:    Note:
    706:    The parameter 'conv' can have one of these values
    707: +     NEP_CONV_ABS  - absolute error ||r||
    708: .     NEP_CONV_REL  - error relative to the eigenvalue l, ||r||/|l|
    709: .     NEP_CONV_NORM - error relative matrix norms, ||r||/sum_i(|f_i(l)|*||A_i||)
    710: -     NEP_CONV_USER - function set by NEPSetConvergenceTestFunction()

    712:    Level: intermediate

    714: .seealso: NEPGetConvergenceTest(), NEPSetConvergenceTestFunction(), NEPSetStoppingTest(), NEPConv
    715: @*/
    716: PetscErrorCode NEPSetConvergenceTest(NEP nep,NEPConv conv)
    717: {
    721:   switch (conv) {
    722:     case NEP_CONV_ABS:  nep->converged = NEPConvergedAbsolute; break;
    723:     case NEP_CONV_REL:  nep->converged = NEPConvergedRelative; break;
    724:     case NEP_CONV_NORM: nep->converged = NEPConvergedNorm; break;
    725:     case NEP_CONV_USER:
    726:       if (!nep->convergeduser) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ORDER,"Must call NEPSetConvergenceTestFunction() first");
    727:       nep->converged = nep->convergeduser;
    728:       break;
    729:     default:
    730:       SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'conv' value");
    731:   }
    732:   nep->conv = conv;
    733:   return(0);
    734: }

    736: /*@
    737:    NEPGetConvergenceTest - Gets the method used to compute the error estimate
    738:    used in the convergence test.

    740:    Not Collective

    742:    Input Parameters:
    743: .  nep   - nonlinear eigensolver context obtained from NEPCreate()

    745:    Output Parameters:
    746: .  conv  - the type of convergence test

    748:    Level: intermediate

    750: .seealso: NEPSetConvergenceTest(), NEPConv
    751: @*/
    752: PetscErrorCode NEPGetConvergenceTest(NEP nep,NEPConv *conv)
    753: {
    757:   *conv = nep->conv;
    758:   return(0);
    759: }

    761: /*@C
    762:    NEPSetStoppingTestFunction - Sets a function to decide when to stop the outer
    763:    iteration of the eigensolver.

    765:    Logically Collective on NEP

    767:    Input Parameters:
    768: +  nep     - nonlinear eigensolver context obtained from NEPCreate()
    769: .  func    - pointer to the stopping test function
    770: .  ctx     - context for private data for the stopping routine (may be null)
    771: -  destroy - a routine for destroying the context (may be null)

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

    776: +   nep    - nonlinear eigensolver context obtained from NEPCreate()
    777: .   its    - current number of iterations
    778: .   max_it - maximum number of iterations
    779: .   nconv  - number of currently converged eigenpairs
    780: .   nev    - number of requested eigenpairs
    781: .   reason - (output) result of the stopping test
    782: -   ctx    - optional context, as set by NEPSetStoppingTestFunction()

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

    790:    Level: advanced

    792: .seealso: NEPSetStoppingTest(), NEPStoppingBasic()
    793: @*/
    794: PetscErrorCode NEPSetStoppingTestFunction(NEP nep,PetscErrorCode (*func)(NEP,PetscInt,PetscInt,PetscInt,PetscInt,NEPConvergedReason*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    795: {

    800:   if (nep->stoppingdestroy) {
    801:     (*nep->stoppingdestroy)(nep->stoppingctx);
    802:   }
    803:   nep->stoppinguser    = func;
    804:   nep->stoppingdestroy = destroy;
    805:   nep->stoppingctx     = ctx;
    806:   if (func == NEPStoppingBasic) nep->stop = NEP_STOP_BASIC;
    807:   else {
    808:     nep->stop     = NEP_STOP_USER;
    809:     nep->stopping = nep->stoppinguser;
    810:   }
    811:   return(0);
    812: }

    814: /*@
    815:    NEPSetStoppingTest - Specifies how to decide the termination of the outer
    816:    loop of the eigensolver.

    818:    Logically Collective on NEP

    820:    Input Parameters:
    821: +  nep  - nonlinear eigensolver context obtained from NEPCreate()
    822: -  stop - the type of stopping test

    824:    Options Database Keys:
    825: +  -nep_stop_basic - Sets the default stopping test
    826: -  -nep_stop_user  - Selects the user-defined stopping test

    828:    Note:
    829:    The parameter 'stop' can have one of these values
    830: +     NEP_STOP_BASIC - default stopping test
    831: -     NEP_STOP_USER  - function set by NEPSetStoppingTestFunction()

    833:    Level: advanced

    835: .seealso: NEPGetStoppingTest(), NEPSetStoppingTestFunction(), NEPSetConvergenceTest(), NEPStop
    836: @*/
    837: PetscErrorCode NEPSetStoppingTest(NEP nep,NEPStop stop)
    838: {
    842:   switch (stop) {
    843:     case NEP_STOP_BASIC: nep->stopping = NEPStoppingBasic; break;
    844:     case NEP_STOP_USER:
    845:       if (!nep->stoppinguser) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ORDER,"Must call NEPSetStoppingTestFunction() first");
    846:       nep->stopping = nep->stoppinguser;
    847:       break;
    848:     default:
    849:       SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'stop' value");
    850:   }
    851:   nep->stop = stop;
    852:   return(0);
    853: }

    855: /*@
    856:    NEPGetStoppingTest - Gets the method used to decide the termination of the outer
    857:    loop of the eigensolver.

    859:    Not Collective

    861:    Input Parameters:
    862: .  nep   - nonlinear eigensolver context obtained from NEPCreate()

    864:    Output Parameters:
    865: .  stop  - the type of stopping test

    867:    Level: advanced

    869: .seealso: NEPSetStoppingTest(), NEPStop
    870: @*/
    871: PetscErrorCode NEPGetStoppingTest(NEP nep,NEPStop *stop)
    872: {
    876:   *stop = nep->stop;
    877:   return(0);
    878: }

    880: /*@
    881:    NEPSetTrackAll - Specifies if the solver must compute the residual of all
    882:    approximate eigenpairs or not.

    884:    Logically Collective on NEP

    886:    Input Parameters:
    887: +  nep      - the eigensolver context
    888: -  trackall - whether compute all residuals or not

    890:    Notes:
    891:    If the user sets trackall=PETSC_TRUE then the solver explicitly computes
    892:    the residual for each eigenpair approximation. Computing the residual is
    893:    usually an expensive operation and solvers commonly compute the associated
    894:    residual to the first unconverged eigenpair.
    895:    The options '-nep_monitor_all' and '-nep_monitor_lg_all' automatically
    896:    activate this option.

    898:    Level: developer

    900: .seealso: NEPGetTrackAll()
    901: @*/
    902: PetscErrorCode NEPSetTrackAll(NEP nep,PetscBool trackall)
    903: {
    907:   nep->trackall = trackall;
    908:   return(0);
    909: }

    911: /*@
    912:    NEPGetTrackAll - Returns the flag indicating whether all residual norms must
    913:    be computed or not.

    915:    Not Collective

    917:    Input Parameter:
    918: .  nep - the eigensolver context

    920:    Output Parameter:
    921: .  trackall - the returned flag

    923:    Level: developer

    925: .seealso: NEPSetTrackAll()
    926: @*/
    927: PetscErrorCode NEPGetTrackAll(NEP nep,PetscBool *trackall)
    928: {
    932:   *trackall = nep->trackall;
    933:   return(0);
    934: }

    936: /*@
    937:    NEPSetRefine - Specifies the refinement type (and options) to be used
    938:    after the solve.

    940:    Logically Collective on NEP

    942:    Input Parameters:
    943: +  nep    - the nonlinear eigensolver context
    944: .  refine - refinement type
    945: .  npart  - number of partitions of the communicator
    946: .  tol    - the convergence tolerance
    947: .  its    - maximum number of refinement iterations
    948: -  scheme - which scheme to be used for solving the involved linear systems

    950:    Options Database Keys:
    951: +  -nep_refine <type> - refinement type, one of <none,simple,multiple>
    952: .  -nep_refine_partitions <n> - the number of partitions
    953: .  -nep_refine_tol <tol> - the tolerance
    954: .  -nep_refine_its <its> - number of iterations
    955: -  -nep_refine_scheme - to set the scheme for the linear solves

    957:    Notes:
    958:    By default, iterative refinement is disabled, since it may be very
    959:    costly. There are two possible refinement strategies: simple and multiple.
    960:    The simple approach performs iterative refinement on each of the
    961:    converged eigenpairs individually, whereas the multiple strategy works
    962:    with the invariant pair as a whole, refining all eigenpairs simultaneously.
    963:    The latter may be required for the case of multiple eigenvalues.

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

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

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

    980:    Level: intermediate

    982: .seealso: NEPGetRefine()
    983: @*/
    984: PetscErrorCode NEPSetRefine(NEP nep,NEPRefine refine,PetscInt npart,PetscReal tol,PetscInt its,NEPRefineScheme scheme)
    985: {
    987:   PetscMPIInt    size;

    996:   nep->refine = refine;
    997:   if (refine) {  /* process parameters only if not REFINE_NONE */
    998:     if (npart!=nep->npart) {
    999:       PetscSubcommDestroy(&nep->refinesubc);
    1000:       KSPDestroy(&nep->refineksp);
    1001:     }
    1002:     if (npart == PETSC_DEFAULT || npart == PETSC_DECIDE) {
    1003:       nep->npart = 1;
    1004:     } else {
    1005:       MPI_Comm_size(PetscObjectComm((PetscObject)nep),&size);
    1006:       if (npart<1 || npart>size) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of npart");
    1007:       nep->npart = npart;
    1008:     }
    1009:     if (tol == PETSC_DEFAULT || tol == PETSC_DECIDE) {
    1010:       nep->rtol = PETSC_DEFAULT;
    1011:     } else {
    1012:       if (tol<=0.0) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    1013:       nep->rtol = tol;
    1014:     }
    1015:     if (its==PETSC_DECIDE || its==PETSC_DEFAULT) {
    1016:       nep->rits = PETSC_DEFAULT;
    1017:     } else {
    1018:       if (its<0) SETERRQ(PetscObjectComm((PetscObject)nep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be >= 0");
    1019:       nep->rits = its;
    1020:     }
    1021:     nep->scheme = scheme;
    1022:   }
    1023:   nep->state = NEP_STATE_INITIAL;
    1024:   return(0);
    1025: }

    1027: /*@C
    1028:    NEPGetRefine - Gets the refinement strategy used by the NEP object, and the
    1029:    associated parameters.

    1031:    Not Collective

    1033:    Input Parameter:
    1034: .  nep - the nonlinear eigensolver context

    1036:    Output Parameters:
    1037: +  refine - refinement type
    1038: .  npart  - number of partitions of the communicator
    1039: .  tol    - the convergence tolerance
    1040: -  its    - maximum number of refinement iterations
    1041: -  scheme - the scheme used for solving linear systems

    1043:    Level: intermediate

    1045:    Note:
    1046:    The user can specify NULL for any parameter that is not needed.

    1048: .seealso: NEPSetRefine()
    1049: @*/
    1050: PetscErrorCode NEPGetRefine(NEP nep,NEPRefine *refine,PetscInt *npart,PetscReal *tol,PetscInt *its,NEPRefineScheme *scheme)
    1051: {
    1054:   if (refine) *refine = nep->refine;
    1055:   if (npart)  *npart  = nep->npart;
    1056:   if (tol)    *tol    = nep->rtol;
    1057:   if (its)    *its    = nep->rits;
    1058:   if (scheme) *scheme = nep->scheme;
    1059:   return(0);
    1060: }

    1062: /*@C
    1063:    NEPSetOptionsPrefix - Sets the prefix used for searching for all
    1064:    NEP options in the database.

    1066:    Logically Collective on NEP

    1068:    Input Parameters:
    1069: +  nep - the nonlinear eigensolver context
    1070: -  prefix - the prefix string to prepend to all NEP option requests

    1072:    Notes:
    1073:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1074:    The first character of all runtime options is AUTOMATICALLY the
    1075:    hyphen.

    1077:    For example, to distinguish between the runtime options for two
    1078:    different NEP contexts, one could call
    1079: .vb
    1080:       NEPSetOptionsPrefix(nep1,"neig1_")
    1081:       NEPSetOptionsPrefix(nep2,"neig2_")
    1082: .ve

    1084:    Level: advanced

    1086: .seealso: NEPAppendOptionsPrefix(), NEPGetOptionsPrefix()
    1087: @*/
    1088: PetscErrorCode NEPSetOptionsPrefix(NEP nep,const char *prefix)
    1089: {

    1094:   if (!nep->V) { NEPGetBV(nep,&nep->V); }
    1095:   BVSetOptionsPrefix(nep->V,prefix);
    1096:   if (!nep->ds) { NEPGetDS(nep,&nep->ds); }
    1097:   DSSetOptionsPrefix(nep->ds,prefix);
    1098:   if (!nep->rg) { NEPGetRG(nep,&nep->rg); }
    1099:   RGSetOptionsPrefix(nep->rg,prefix);
    1100:   PetscObjectSetOptionsPrefix((PetscObject)nep,prefix);
    1101:   return(0);
    1102: }

    1104: /*@C
    1105:    NEPAppendOptionsPrefix - Appends to the prefix used for searching for all
    1106:    NEP options in the database.

    1108:    Logically Collective on NEP

    1110:    Input Parameters:
    1111: +  nep - the nonlinear eigensolver context
    1112: -  prefix - the prefix string to prepend to all NEP option requests

    1114:    Notes:
    1115:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1116:    The first character of all runtime options is AUTOMATICALLY the hyphen.

    1118:    Level: advanced

    1120: .seealso: NEPSetOptionsPrefix(), NEPGetOptionsPrefix()
    1121: @*/
    1122: PetscErrorCode NEPAppendOptionsPrefix(NEP nep,const char *prefix)
    1123: {

    1128:   if (!nep->V) { NEPGetBV(nep,&nep->V); }
    1129:   BVAppendOptionsPrefix(nep->V,prefix);
    1130:   if (!nep->ds) { NEPGetDS(nep,&nep->ds); }
    1131:   DSAppendOptionsPrefix(nep->ds,prefix);
    1132:   if (!nep->rg) { NEPGetRG(nep,&nep->rg); }
    1133:   RGAppendOptionsPrefix(nep->rg,prefix);
    1134:   PetscObjectAppendOptionsPrefix((PetscObject)nep,prefix);
    1135:   return(0);
    1136: }

    1138: /*@C
    1139:    NEPGetOptionsPrefix - Gets the prefix used for searching for all
    1140:    NEP options in the database.

    1142:    Not Collective

    1144:    Input Parameters:
    1145: .  nep - the nonlinear eigensolver context

    1147:    Output Parameters:
    1148: .  prefix - pointer to the prefix string used is returned

    1150:    Note:
    1151:    On the Fortran side, the user should pass in a string 'prefix' of
    1152:    sufficient length to hold the prefix.

    1154:    Level: advanced

    1156: .seealso: NEPSetOptionsPrefix(), NEPAppendOptionsPrefix()
    1157: @*/
    1158: PetscErrorCode NEPGetOptionsPrefix(NEP nep,const char *prefix[])
    1159: {

    1165:   PetscObjectGetOptionsPrefix((PetscObject)nep,prefix);
    1166:   return(0);
    1167: }