Date: 2021-02-01T14:42:10+00:00

Actual source code: pepopts.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:    PEP routines related to options that can be set via the command-line
     12:    or procedurally
     13: */

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

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

     22:    Collective on pep

     24:    Input Parameters:
     25: +  pep      - the polynomial eigensolver context
     26: .  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: PEPMonitorSet(), PEPSetTrackAll(), PEPConvMonitorSetFromOptions()
     35: @*/
     36: PetscErrorCode PEPMonitorSetFromOptions(PEP pep,const char name[],const char help[],const char manual[],PetscErrorCode (*monitor)(PEP,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,PetscViewerAndFormat*),PetscBool trackall)
     37: {
     38:   PetscErrorCode       ierr;
     39:   PetscBool            flg;
     40:   PetscViewer          viewer;
     41:   PetscViewerFormat    format;
     42:   PetscViewerAndFormat *vf;

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

     57: /*@C
     58:    PEPConvMonitorSetFromOptions - 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 pep

     63:    Input Parameters:
     64: +  pep      - the polynomial 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: PEPMonitorSet(), PEPMonitorSetFromOptions()
     73: @*/
     74: PetscErrorCode PEPConvMonitorSetFromOptions(PEP pep,const char name[],const char help[],const char manual[],PetscErrorCode (*monitor)(PEP,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)pep),((PetscObject)pep)->options,((PetscObject)pep)->prefix,name,&viewer,&format,&flg);
     84:   if (flg) {
     85:     SlepcConvMonitorCreate(viewer,format,&ctx);
     86:     PetscObjectDereference((PetscObject)viewer);
     87:     PEPMonitorSet(pep,(PetscErrorCode (*)(PEP,PetscInt,PetscInt,PetscScalar*,PetscScalar*,PetscReal*,PetscInt,void*))monitor,ctx,(PetscErrorCode (*)(void**))SlepcConvMonitorDestroy);
     88:   }
     89:   return(0);
     90: }

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

     97:    Collective on pep

     99:    Input Parameters:
    100: .  pep - the polynomial eigensolver context

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

    105:    Level: beginner
    106: @*/
    107: PetscErrorCode PEPSetFromOptions(PEP pep)
    108: {
    109:   PetscErrorCode  ierr;
    110:   char            type[256];
    111:   PetscBool       set,flg,flg1,flg2,flg3,flg4,flg5;
    112:   PetscReal       r,t,array[2]={0,0};
    113:   PetscScalar     s;
    114:   PetscInt        i,j,k;
    115:   PetscDrawLG     lg;
    116:   PEPScale        scale;
    117:   PEPRefine       refine;
    118:   PEPRefineScheme scheme;

    122:   PEPRegisterAll();
    123:   PetscObjectOptionsBegin((PetscObject)pep);
    124:     PetscOptionsFList("-pep_type","Polynomial eigensolver method","PEPSetType",PEPList,(char*)(((PetscObject)pep)->type_name?((PetscObject)pep)->type_name:PEPTOAR),type,sizeof(type),&flg);
    125:     if (flg) {
    126:       PEPSetType(pep,type);
    127:     } else if (!((PetscObject)pep)->type_name) {
    128:       PEPSetType(pep,PEPTOAR);
    129:     }

    131:     PetscOptionsBoolGroupBegin("-pep_general","General polynomial eigenvalue problem","PEPSetProblemType",&flg);
    132:     if (flg) { PEPSetProblemType(pep,PEP_GENERAL); }
    133:     PetscOptionsBoolGroup("-pep_hermitian","Hermitian polynomial eigenvalue problem","PEPSetProblemType",&flg);
    134:     if (flg) { PEPSetProblemType(pep,PEP_HERMITIAN); }
    135:     PetscOptionsBoolGroup("-pep_hyperbolic","Hyperbolic polynomial eigenvalue problem","PEPSetProblemType",&flg);
    136:     if (flg) { PEPSetProblemType(pep,PEP_HYPERBOLIC); }
    137:     PetscOptionsBoolGroupEnd("-pep_gyroscopic","Gyroscopic polynomial eigenvalue problem","PEPSetProblemType",&flg);
    138:     if (flg) { PEPSetProblemType(pep,PEP_GYROSCOPIC); }

    140:     scale = pep->scale;
    141:     PetscOptionsEnum("-pep_scale","Scaling strategy","PEPSetScale",PEPScaleTypes,(PetscEnum)scale,(PetscEnum*)&scale,&flg1);
    142:     r = pep->sfactor;
    143:     PetscOptionsReal("-pep_scale_factor","Scale factor","PEPSetScale",pep->sfactor,&r,&flg2);
    144:     if (!flg2 && r==1.0) r = PETSC_DEFAULT;
    145:     j = pep->sits;
    146:     PetscOptionsInt("-pep_scale_its","Number of iterations in diagonal scaling","PEPSetScale",pep->sits,&j,&flg3);
    147:     t = pep->slambda;
    148:     PetscOptionsReal("-pep_scale_lambda","Estimate of eigenvalue (modulus) for diagonal scaling","PEPSetScale",pep->slambda,&t,&flg4);
    149:     if (flg1 || flg2 || flg3 || flg4) { PEPSetScale(pep,scale,r,NULL,NULL,j,t); }

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

    153:     refine = pep->refine;
    154:     PetscOptionsEnum("-pep_refine","Iterative refinement method","PEPSetRefine",PEPRefineTypes,(PetscEnum)refine,(PetscEnum*)&refine,&flg1);
    155:     i = pep->npart;
    156:     PetscOptionsInt("-pep_refine_partitions","Number of partitions of the communicator for iterative refinement","PEPSetRefine",pep->npart,&i,&flg2);
    157:     r = pep->rtol;
    158:     PetscOptionsReal("-pep_refine_tol","Tolerance for iterative refinement","PEPSetRefine",pep->rtol==PETSC_DEFAULT?SLEPC_DEFAULT_TOL/1000:pep->rtol,&r,&flg3);
    159:     j = pep->rits;
    160:     PetscOptionsInt("-pep_refine_its","Maximum number of iterations for iterative refinement","PEPSetRefine",pep->rits,&j,&flg4);
    161:     scheme = pep->scheme;
    162:     PetscOptionsEnum("-pep_refine_scheme","Scheme used for linear systems within iterative refinement","PEPSetRefine",PEPRefineSchemes,(PetscEnum)scheme,(PetscEnum*)&scheme,&flg5);
    163:     if (flg1 || flg2 || flg3 || flg4 || flg5) { PEPSetRefine(pep,refine,i,r,j,scheme); }

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

    171:     PetscOptionsBoolGroupBegin("-pep_conv_rel","Relative error convergence test","PEPSetConvergenceTest",&flg);
    172:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_REL); }
    173:     PetscOptionsBoolGroup("-pep_conv_norm","Convergence test relative to the matrix norms","PEPSetConvergenceTest",&flg);
    174:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_NORM); }
    175:     PetscOptionsBoolGroup("-pep_conv_abs","Absolute error convergence test","PEPSetConvergenceTest",&flg);
    176:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_ABS); }
    177:     PetscOptionsBoolGroupEnd("-pep_conv_user","User-defined convergence test","PEPSetConvergenceTest",&flg);
    178:     if (flg) { PEPSetConvergenceTest(pep,PEP_CONV_USER); }

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

    185:     i = pep->nev;
    186:     PetscOptionsInt("-pep_nev","Number of eigenvalues to compute","PEPSetDimensions",pep->nev,&i,&flg1);
    187:     j = pep->ncv;
    188:     PetscOptionsInt("-pep_ncv","Number of basis vectors","PEPSetDimensions",pep->ncv,&j,&flg2);
    189:     k = pep->mpd;
    190:     PetscOptionsInt("-pep_mpd","Maximum dimension of projected problem","PEPSetDimensions",pep->mpd,&k,&flg3);
    191:     if (flg1 || flg2 || flg3) { PEPSetDimensions(pep,i,j,k); }

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

    195:     PetscOptionsBoolGroupBegin("-pep_largest_magnitude","Compute largest eigenvalues in magnitude","PEPSetWhichEigenpairs",&flg);
    196:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_LARGEST_MAGNITUDE); }
    197:     PetscOptionsBoolGroup("-pep_smallest_magnitude","Compute smallest eigenvalues in magnitude","PEPSetWhichEigenpairs",&flg);
    198:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_SMALLEST_MAGNITUDE); }
    199:     PetscOptionsBoolGroup("-pep_largest_real","Compute eigenvalues with largest real parts","PEPSetWhichEigenpairs",&flg);
    200:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_LARGEST_REAL); }
    201:     PetscOptionsBoolGroup("-pep_smallest_real","Compute eigenvalues with smallest real parts","PEPSetWhichEigenpairs",&flg);
    202:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_SMALLEST_REAL); }
    203:     PetscOptionsBoolGroup("-pep_largest_imaginary","Compute eigenvalues with largest imaginary parts","PEPSetWhichEigenpairs",&flg);
    204:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_LARGEST_IMAGINARY); }
    205:     PetscOptionsBoolGroup("-pep_smallest_imaginary","Compute eigenvalues with smallest imaginary parts","PEPSetWhichEigenpairs",&flg);
    206:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_SMALLEST_IMAGINARY); }
    207:     PetscOptionsBoolGroup("-pep_target_magnitude","Compute eigenvalues closest to target","PEPSetWhichEigenpairs",&flg);
    208:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_TARGET_MAGNITUDE); }
    209:     PetscOptionsBoolGroup("-pep_target_real","Compute eigenvalues with real parts closest to target","PEPSetWhichEigenpairs",&flg);
    210:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_TARGET_REAL); }
    211:     PetscOptionsBoolGroup("-pep_target_imaginary","Compute eigenvalues with imaginary parts closest to target","PEPSetWhichEigenpairs",&flg);
    212:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_TARGET_IMAGINARY); }
    213:     PetscOptionsBoolGroupEnd("-pep_all","Compute all eigenvalues in an interval or a region","PEPSetWhichEigenpairs",&flg);
    214:     if (flg) { PEPSetWhichEigenpairs(pep,PEP_ALL); }

    216:     PetscOptionsScalar("-pep_target","Value of the target","PEPSetTarget",pep->target,&s,&flg);
    217:     if (flg) {
    218:       if (pep->which!=PEP_TARGET_REAL && pep->which!=PEP_TARGET_IMAGINARY) {
    219:         PEPSetWhichEigenpairs(pep,PEP_TARGET_MAGNITUDE);
    220:       }
    221:       PEPSetTarget(pep,s);
    222:     }

    224:     k = 2;
    225:     PetscOptionsRealArray("-pep_interval","Computational interval (two real values separated with a comma without spaces)","PEPSetInterval",array,&k,&flg);
    226:     if (flg) {
    227:       if (k<2) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_SIZ,"Must pass two values in -pep_interval (comma-separated without spaces)");
    228:       PEPSetWhichEigenpairs(pep,PEP_ALL);
    229:       PEPSetInterval(pep,array[0],array[1]);
    230:     }

    232:     /* -----------------------------------------------------------------------*/
    233:     /*
    234:       Cancels all monitors hardwired into code before call to PEPSetFromOptions()
    235:     */
    236:     PetscOptionsBool("-pep_monitor_cancel","Remove any hardwired monitor routines","PEPMonitorCancel",PETSC_FALSE,&flg,&set);
    237:     if (set && flg) {
    238:       PEPMonitorCancel(pep);
    239:     }
    240:     /*
    241:       Text monitors
    242:     */
    243:     PEPMonitorSetFromOptions(pep,"-pep_monitor","Monitor first unconverged approximate eigenvalue and error estimate","PEPMonitorFirst",PEPMonitorFirst,PETSC_FALSE);
    244:     PEPConvMonitorSetFromOptions(pep,"-pep_monitor_conv","Monitor approximate eigenvalues and error estimates as they converge","PEPMonitorConverged",PEPMonitorConverged);
    245:     PEPMonitorSetFromOptions(pep,"-pep_monitor_all","Monitor approximate eigenvalues and error estimates","PEPMonitorAll",PEPMonitorAll,PETSC_TRUE);
    246:     /*
    247:       Line graph monitors
    248:     */
    249:     PetscOptionsBool("-pep_monitor_lg","Monitor first unconverged approximate error estimate graphically","PEPMonitorSet",PETSC_FALSE,&flg,&set);
    250:     if (set && flg) {
    251:       PEPMonitorLGCreate(PetscObjectComm((PetscObject)pep),NULL,"Error estimates",PETSC_DECIDE,PETSC_DECIDE,300,300,&lg);
    252:       PEPMonitorSet(pep,PEPMonitorLG,lg,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
    253:     }
    254:     PetscOptionsBool("-pep_monitor_lg_all","Monitor error estimates graphically","PEPMonitorSet",PETSC_FALSE,&flg,&set);
    255:     if (set && flg) {
    256:       PEPMonitorLGCreate(PetscObjectComm((PetscObject)pep),NULL,"Error estimates",PETSC_DECIDE,PETSC_DECIDE,300,300,&lg);
    257:       PEPMonitorSet(pep,PEPMonitorLGAll,lg,(PetscErrorCode (*)(void**))PetscDrawLGDestroy);
    258:       PEPSetTrackAll(pep,PETSC_TRUE);
    259:     }

    261:     /* -----------------------------------------------------------------------*/
    262:     PetscOptionsName("-pep_view","Print detailed information on solver used","PEPView",NULL);
    263:     PetscOptionsName("-pep_view_vectors","View computed eigenvectors","PEPVectorsView",NULL);
    264:     PetscOptionsName("-pep_view_values","View computed eigenvalues","PEPValuesView",NULL);
    265:     PetscOptionsName("-pep_converged_reason","Print reason for convergence, and number of iterations","PEPConvergedReasonView",NULL);
    266:     PetscOptionsName("-pep_error_absolute","Print absolute errors of each eigenpair","PEPErrorView",NULL);
    267:     PetscOptionsName("-pep_error_relative","Print relative errors of each eigenpair","PEPErrorView",NULL);
    268:     PetscOptionsName("-pep_error_backward","Print backward errors of each eigenpair","PEPErrorView",NULL);

    270:     if (pep->ops->setfromoptions) {
    271:       (*pep->ops->setfromoptions)(PetscOptionsObject,pep);
    272:     }
    273:     PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)pep);
    274:   PetscOptionsEnd();

    276:   if (!pep->V) { PEPGetBV(pep,&pep->V); }
    277:   BVSetFromOptions(pep->V);
    278:   if (!pep->rg) { PEPGetRG(pep,&pep->rg); }
    279:   RGSetFromOptions(pep->rg);
    280:   if (!pep->ds) { PEPGetDS(pep,&pep->ds); }
    281:   DSSetFromOptions(pep->ds);
    282:   if (!pep->st) { PEPGetST(pep,&pep->st); }
    283:   PEPSetDefaultST(pep);
    284:   STSetFromOptions(pep->st);
    285:   if (!pep->refineksp) { PEPRefineGetKSP(pep,&pep->refineksp); }
    286:   KSPSetFromOptions(pep->refineksp);
    287:   return(0);
    288: }

    290: /*@C
    291:    PEPGetTolerances - Gets the tolerance and maximum iteration count used
    292:    by the PEP convergence tests.

    294:    Not Collective

    296:    Input Parameter:
    297: .  pep - the polynomial eigensolver context

    299:    Output Parameters:
    300: +  tol - the convergence tolerance
    301: -  maxits - maximum number of iterations

    303:    Notes:
    304:    The user can specify NULL for any parameter that is not needed.

    306:    Level: intermediate

    308: .seealso: PEPSetTolerances()
    309: @*/
    310: PetscErrorCode PEPGetTolerances(PEP pep,PetscReal *tol,PetscInt *maxits)
    311: {
    314:   if (tol)    *tol    = pep->tol;
    315:   if (maxits) *maxits = pep->max_it;
    316:   return(0);
    317: }

    319: /*@
    320:    PEPSetTolerances - Sets the tolerance and maximum iteration count used
    321:    by the PEP convergence tests.

    323:    Logically Collective on pep

    325:    Input Parameters:
    326: +  pep - the polynomial eigensolver context
    327: .  tol - the convergence tolerance
    328: -  maxits - maximum number of iterations to use

    330:    Options Database Keys:
    331: +  -pep_tol <tol> - Sets the convergence tolerance
    332: -  -pep_max_it <maxits> - Sets the maximum number of iterations allowed

    334:    Notes:
    335:    Use PETSC_DEFAULT for either argument to assign a reasonably good value.

    337:    Level: intermediate

    339: .seealso: PEPGetTolerances()
    340: @*/
    341: PetscErrorCode PEPSetTolerances(PEP pep,PetscReal tol,PetscInt maxits)
    342: {
    347:   if (tol == PETSC_DEFAULT) {
    348:     pep->tol   = PETSC_DEFAULT;
    349:     pep->state = PEP_STATE_INITIAL;
    350:   } else {
    351:     if (tol <= 0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    352:     pep->tol = tol;
    353:   }
    354:   if (maxits == PETSC_DEFAULT || maxits == PETSC_DECIDE) {
    355:     pep->max_it = PETSC_DEFAULT;
    356:     pep->state  = PEP_STATE_INITIAL;
    357:   } else {
    358:     if (maxits <= 0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
    359:     pep->max_it = maxits;
    360:   }
    361:   return(0);
    362: }

    364: /*@C
    365:    PEPGetDimensions - Gets the number of eigenvalues to compute
    366:    and the dimension of the subspace.

    368:    Not Collective

    370:    Input Parameter:
    371: .  pep - the polynomial eigensolver context

    373:    Output Parameters:
    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:    Notes:
    379:    The user can specify NULL for any parameter that is not needed.

    381:    Level: intermediate

    383: .seealso: PEPSetDimensions()
    384: @*/
    385: PetscErrorCode PEPGetDimensions(PEP pep,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
    386: {
    389:   if (nev) *nev = pep->nev;
    390:   if (ncv) *ncv = pep->ncv;
    391:   if (mpd) *mpd = pep->mpd;
    392:   return(0);
    393: }

    395: /*@
    396:    PEPSetDimensions - Sets the number of eigenvalues to compute
    397:    and the dimension of the subspace.

    399:    Logically Collective on pep

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

    407:    Options Database Keys:
    408: +  -pep_nev <nev> - Sets the number of eigenvalues
    409: .  -pep_ncv <ncv> - Sets the dimension of the subspace
    410: -  -pep_mpd <mpd> - Sets the maximum projected dimension

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

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

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

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

    428:    Level: intermediate

    430: .seealso: PEPGetDimensions(), PEPSetInterval(), PEPSTOARSetDimensions()
    431: @*/
    432: PetscErrorCode PEPSetDimensions(PEP pep,PetscInt nev,PetscInt ncv,PetscInt mpd)
    433: {
    439:   if (nev<1) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
    440:   pep->nev = nev;
    441:   if (ncv == PETSC_DECIDE || ncv == PETSC_DEFAULT) {
    442:     pep->ncv = PETSC_DEFAULT;
    443:   } else {
    444:     if (ncv<1) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
    445:     pep->ncv = ncv;
    446:   }
    447:   if (mpd == PETSC_DECIDE || mpd == PETSC_DEFAULT) {
    448:     pep->mpd = PETSC_DEFAULT;
    449:   } else {
    450:     if (mpd<1) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
    451:     pep->mpd = mpd;
    452:   }
    453:   pep->state = PEP_STATE_INITIAL;
    454:   return(0);
    455: }

    457: /*@
    458:    PEPSetWhichEigenpairs - Specifies which portion of the spectrum is
    459:    to be sought.

    461:    Logically Collective on pep

    463:    Input Parameters:
    464: +  pep   - eigensolver context obtained from PEPCreate()
    465: -  which - the portion of the spectrum to be sought

    467:    Possible values:
    468:    The parameter 'which' can have one of these values

    470: +     PEP_LARGEST_MAGNITUDE - largest eigenvalues in magnitude (default)
    471: .     PEP_SMALLEST_MAGNITUDE - smallest eigenvalues in magnitude
    472: .     PEP_LARGEST_REAL - largest real parts
    473: .     PEP_SMALLEST_REAL - smallest real parts
    474: .     PEP_LARGEST_IMAGINARY - largest imaginary parts
    475: .     PEP_SMALLEST_IMAGINARY - smallest imaginary parts
    476: .     PEP_TARGET_MAGNITUDE - eigenvalues closest to the target (in magnitude)
    477: .     PEP_TARGET_REAL - eigenvalues with real part closest to target
    478: .     PEP_TARGET_IMAGINARY - eigenvalues with imaginary part closest to target
    479: .     PEP_ALL - all eigenvalues contained in a given interval
    480: -     PEP_WHICH_USER - user defined ordering set with PEPSetEigenvalueComparison()

    482:    Options Database Keys:
    483: +   -pep_largest_magnitude - Sets largest eigenvalues in magnitude
    484: .   -pep_smallest_magnitude - Sets smallest eigenvalues in magnitude
    485: .   -pep_largest_real - Sets largest real parts
    486: .   -pep_smallest_real - Sets smallest real parts
    487: .   -pep_largest_imaginary - Sets largest imaginary parts
    488: .   -pep_smallest_imaginary - Sets smallest imaginary parts
    489: .   -pep_target_magnitude - Sets eigenvalues closest to target
    490: .   -pep_target_real - Sets real parts closest to target
    491: .   -pep_target_imaginary - Sets imaginary parts closest to target
    492: -   -pep_all - Sets all eigenvalues in an interval

    494:    Notes:
    495:    Not all eigensolvers implemented in PEP account for all the possible values
    496:    stated above. If SLEPc is compiled for real numbers PEP_LARGEST_IMAGINARY
    497:    and PEP_SMALLEST_IMAGINARY use the absolute value of the imaginary part
    498:    for eigenvalue selection.

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

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

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

    510:    Level: intermediate

    512: .seealso: PEPGetWhichEigenpairs(), PEPSetTarget(), PEPSetInterval(),
    513:           PEPSetDimensions(), PEPSetEigenvalueComparison(), PEPWhich
    514: @*/
    515: PetscErrorCode PEPSetWhichEigenpairs(PEP pep,PEPWhich which)
    516: {
    520:   switch (which) {
    521:     case PEP_LARGEST_MAGNITUDE:
    522:     case PEP_SMALLEST_MAGNITUDE:
    523:     case PEP_LARGEST_REAL:
    524:     case PEP_SMALLEST_REAL:
    525:     case PEP_LARGEST_IMAGINARY:
    526:     case PEP_SMALLEST_IMAGINARY:
    527:     case PEP_TARGET_MAGNITUDE:
    528:     case PEP_TARGET_REAL:
    529: #if defined(PETSC_USE_COMPLEX)
    530:     case PEP_TARGET_IMAGINARY:
    531: #endif
    532:     case PEP_ALL:
    533:     case PEP_WHICH_USER:
    534:       if (pep->which != which) {
    535:         pep->state = PEP_STATE_INITIAL;
    536:         pep->which = which;
    537:       }
    538:       break;
    539: #if !defined(PETSC_USE_COMPLEX)
    540:     case PEP_TARGET_IMAGINARY:
    541:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_SUP,"PEP_TARGET_IMAGINARY can be used only with complex scalars");
    542: #endif
    543:     default:
    544:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'which' value");
    545:   }
    546:   return(0);
    547: }

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

    553:     Not Collective

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

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

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

    564:     Level: intermediate

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

    577: /*@C
    578:    PEPSetEigenvalueComparison - Specifies the eigenvalue comparison function
    579:    when PEPSetWhichEigenpairs() is set to PEP_WHICH_USER.

    581:    Logically Collective on pep

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

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

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

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

    604:    Level: advanced

    606: .seealso: PEPSetWhichEigenpairs(), PEPWhich
    607: @*/
    608: PetscErrorCode PEPSetEigenvalueComparison(PEP pep,PetscErrorCode (*func)(PetscScalar,PetscScalar,PetscScalar,PetscScalar,PetscInt*,void*),void* ctx)
    609: {
    612:   pep->sc->comparison    = func;
    613:   pep->sc->comparisonctx = ctx;
    614:   pep->which             = PEP_WHICH_USER;
    615:   return(0);
    616: }

    618: /*@
    619:    PEPSetProblemType - Specifies the type of the polynomial eigenvalue problem.

    621:    Logically Collective on pep

    623:    Input Parameters:
    624: +  pep  - the polynomial eigensolver context
    625: -  type - a known type of polynomial eigenvalue problem

    627:    Options Database Keys:
    628: +  -pep_general - general problem with no particular structure
    629: .  -pep_hermitian - problem whose coefficient matrices are Hermitian
    630: .  -pep_hyperbolic - Hermitian problem that satisfies the definition of hyperbolic
    631: -  -pep_gyroscopic - problem with Hamiltonian structure

    633:    Notes:
    634:    Allowed values for the problem type are: general (PEP_GENERAL), Hermitian
    635:    (PEP_HERMITIAN), hyperbolic (PEP_HYPERBOLIC), and gyroscopic (PEP_GYROSCOPIC).

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

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

    646:    Level: intermediate

    648: .seealso: PEPSetOperators(), PEPSetType(), PEPGetProblemType(), PEPProblemType
    649: @*/
    650: PetscErrorCode PEPSetProblemType(PEP pep,PEPProblemType type)
    651: {
    655:   if (type!=PEP_GENERAL && type!=PEP_HERMITIAN && type!=PEP_HYPERBOLIC && type!=PEP_GYROSCOPIC) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_WRONG,"Unknown eigenvalue problem type");
    656:   if (type != pep->problem_type) {
    657:     pep->problem_type = type;
    658:     pep->state = PEP_STATE_INITIAL;
    659:   }
    660:   return(0);
    661: }

    663: /*@
    664:    PEPGetProblemType - Gets the problem type from the PEP object.

    666:    Not Collective

    668:    Input Parameter:
    669: .  pep - the polynomial eigensolver context

    671:    Output Parameter:
    672: .  type - the problem type

    674:    Level: intermediate

    676: .seealso: PEPSetProblemType(), PEPProblemType
    677: @*/
    678: PetscErrorCode PEPGetProblemType(PEP pep,PEPProblemType *type)
    679: {
    683:   *type = pep->problem_type;
    684:   return(0);
    685: }

    687: /*@
    688:    PEPSetBasis - Specifies the type of polynomial basis used to describe the
    689:    polynomial eigenvalue problem.

    691:    Logically Collective on pep

    693:    Input Parameters:
    694: +  pep   - the polynomial eigensolver context
    695: -  basis - the type of polynomial basis

    697:    Options Database Key:
    698: .  -pep_basis <basis> - Select the basis type

    700:    Notes:
    701:    By default, the coefficient matrices passed via PEPSetOperators() are
    702:    expressed in the monomial basis, i.e.
    703:    P(lambda) = A_0 + lambda*A_1 + lambda^2*A_2 + ... + lambda^d*A_d.
    704:    Other polynomial bases may have better numerical behaviour, but the user
    705:    must then pass the coefficient matrices accordingly.

    707:    Level: intermediate

    709: .seealso: PEPSetOperators(), PEPGetBasis(), PEPBasis
    710: @*/
    711: PetscErrorCode PEPSetBasis(PEP pep,PEPBasis basis)
    712: {
    716:   pep->basis = basis;
    717:   return(0);
    718: }

    720: /*@
    721:    PEPGetBasis - Gets the type of polynomial basis from the PEP object.

    723:    Not Collective

    725:    Input Parameter:
    726: .  pep - the polynomial eigensolver context

    728:    Output Parameter:
    729: .  basis - the polynomial basis

    731:    Level: intermediate

    733: .seealso: PEPSetBasis(), PEPBasis
    734: @*/
    735: PetscErrorCode PEPGetBasis(PEP pep,PEPBasis *basis)
    736: {
    740:   *basis = pep->basis;
    741:   return(0);
    742: }

    744: /*@
    745:    PEPSetTrackAll - Specifies if the solver must compute the residual of all
    746:    approximate eigenpairs or not.

    748:    Logically Collective on pep

    750:    Input Parameters:
    751: +  pep      - the eigensolver context
    752: -  trackall - whether compute all residuals or not

    754:    Notes:
    755:    If the user sets trackall=PETSC_TRUE then the solver explicitly computes
    756:    the residual for each eigenpair approximation. Computing the residual is
    757:    usually an expensive operation and solvers commonly compute the associated
    758:    residual to the first unconverged eigenpair.
    759:    The options '-pep_monitor_all' and '-pep_monitor_lg_all' automatically
    760:    activate this option.

    762:    Level: developer

    764: .seealso: PEPGetTrackAll()
    765: @*/
    766: PetscErrorCode PEPSetTrackAll(PEP pep,PetscBool trackall)
    767: {
    771:   pep->trackall = trackall;
    772:   return(0);
    773: }

    775: /*@
    776:    PEPGetTrackAll - Returns the flag indicating whether all residual norms must
    777:    be computed or not.

    779:    Not Collective

    781:    Input Parameter:
    782: .  pep - the eigensolver context

    784:    Output Parameter:
    785: .  trackall - the returned flag

    787:    Level: developer

    789: .seealso: PEPSetTrackAll()
    790: @*/
    791: PetscErrorCode PEPGetTrackAll(PEP pep,PetscBool *trackall)
    792: {
    796:   *trackall = pep->trackall;
    797:   return(0);
    798: }

    800: /*@C
    801:    PEPSetConvergenceTestFunction - Sets a function to compute the error estimate
    802:    used in the convergence test.

    804:    Logically Collective on pep

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

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

    815: +   pep    - eigensolver context obtained from PEPCreate()
    816: .   eigr   - real part of the eigenvalue
    817: .   eigi   - imaginary part of the eigenvalue
    818: .   res    - residual norm associated to the eigenpair
    819: .   errest - (output) computed error estimate
    820: -   ctx    - optional context, as set by PEPSetConvergenceTestFunction()

    822:    Note:
    823:    If the error estimate returned by the convergence test function is less than
    824:    the tolerance, then the eigenvalue is accepted as converged.

    826:    Level: advanced

    828: .seealso: PEPSetConvergenceTest(), PEPSetTolerances()
    829: @*/
    830: PetscErrorCode PEPSetConvergenceTestFunction(PEP pep,PetscErrorCode (*func)(PEP,PetscScalar,PetscScalar,PetscReal,PetscReal*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    831: {

    836:   if (pep->convergeddestroy) {
    837:     (*pep->convergeddestroy)(pep->convergedctx);
    838:   }
    839:   pep->convergeduser    = func;
    840:   pep->convergeddestroy = destroy;
    841:   pep->convergedctx     = ctx;
    842:   if (func == PEPConvergedRelative) pep->conv = PEP_CONV_REL;
    843:   else if (func == PEPConvergedNorm) pep->conv = PEP_CONV_NORM;
    844:   else if (func == PEPConvergedAbsolute) pep->conv = PEP_CONV_ABS;
    845:   else {
    846:     pep->conv      = PEP_CONV_USER;
    847:     pep->converged = pep->convergeduser;
    848:   }
    849:   return(0);
    850: }

    852: /*@
    853:    PEPSetConvergenceTest - Specifies how to compute the error estimate
    854:    used in the convergence test.

    856:    Logically Collective on pep

    858:    Input Parameters:
    859: +  pep  - eigensolver context obtained from PEPCreate()
    860: -  conv - the type of convergence test

    862:    Options Database Keys:
    863: +  -pep_conv_abs    - Sets the absolute convergence test
    864: .  -pep_conv_rel    - Sets the convergence test relative to the eigenvalue
    865: .  -pep_conv_norm   - Sets the convergence test relative to the matrix norms
    866: -  -pep_conv_user   - Selects the user-defined convergence test

    868:    Note:
    869:    The parameter 'conv' can have one of these values
    870: +     PEP_CONV_ABS    - absolute error ||r||
    871: .     PEP_CONV_REL    - error relative to the eigenvalue l, ||r||/|l|
    872: .     PEP_CONV_NORM   - error relative matrix norms, ||r||/sum_i(l^i*||A_i||)
    873: -     PEP_CONV_USER   - function set by PEPSetConvergenceTestFunction()

    875:    Level: intermediate

    877: .seealso: PEPGetConvergenceTest(), PEPSetConvergenceTestFunction(), PEPSetStoppingTest(), PEPConv
    878: @*/
    879: PetscErrorCode PEPSetConvergenceTest(PEP pep,PEPConv conv)
    880: {
    884:   switch (conv) {
    885:     case PEP_CONV_ABS:  pep->converged = PEPConvergedAbsolute; break;
    886:     case PEP_CONV_REL:  pep->converged = PEPConvergedRelative; break;
    887:     case PEP_CONV_NORM: pep->converged = PEPConvergedNorm; break;
    888:     case PEP_CONV_USER:
    889:       if (!pep->convergeduser) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ORDER,"Must call PEPSetConvergenceTestFunction() first");
    890:       pep->converged = pep->convergeduser;
    891:       break;
    892:     default:
    893:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'conv' value");
    894:   }
    895:   pep->conv = conv;
    896:   return(0);
    897: }

    899: /*@
    900:    PEPGetConvergenceTest - Gets the method used to compute the error estimate
    901:    used in the convergence test.

    903:    Not Collective

    905:    Input Parameters:
    906: .  pep   - eigensolver context obtained from PEPCreate()

    908:    Output Parameters:
    909: .  conv  - the type of convergence test

    911:    Level: intermediate

    913: .seealso: PEPSetConvergenceTest(), PEPConv
    914: @*/
    915: PetscErrorCode PEPGetConvergenceTest(PEP pep,PEPConv *conv)
    916: {
    920:   *conv = pep->conv;
    921:   return(0);
    922: }

    924: /*@C
    925:    PEPSetStoppingTestFunction - Sets a function to decide when to stop the outer
    926:    iteration of the eigensolver.

    928:    Logically Collective on pep

    930:    Input Parameters:
    931: +  pep     - eigensolver context obtained from PEPCreate()
    932: .  func    - pointer to the stopping test function
    933: .  ctx     - context for private data for the stopping routine (may be null)
    934: -  destroy - a routine for destroying the context (may be null)

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

    939: +   pep    - eigensolver context obtained from PEPCreate()
    940: .   its    - current number of iterations
    941: .   max_it - maximum number of iterations
    942: .   nconv  - number of currently converged eigenpairs
    943: .   nev    - number of requested eigenpairs
    944: .   reason - (output) result of the stopping test
    945: -   ctx    - optional context, as set by PEPSetStoppingTestFunction()

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

    953:    Level: advanced

    955: .seealso: PEPSetStoppingTest(), PEPStoppingBasic()
    956: @*/
    957: PetscErrorCode PEPSetStoppingTestFunction(PEP pep,PetscErrorCode (*func)(PEP,PetscInt,PetscInt,PetscInt,PetscInt,PEPConvergedReason*,void*),void* ctx,PetscErrorCode (*destroy)(void*))
    958: {

    963:   if (pep->stoppingdestroy) {
    964:     (*pep->stoppingdestroy)(pep->stoppingctx);
    965:   }
    966:   pep->stoppinguser    = func;
    967:   pep->stoppingdestroy = destroy;
    968:   pep->stoppingctx     = ctx;
    969:   if (func == PEPStoppingBasic) pep->stop = PEP_STOP_BASIC;
    970:   else {
    971:     pep->stop     = PEP_STOP_USER;
    972:     pep->stopping = pep->stoppinguser;
    973:   }
    974:   return(0);
    975: }

    977: /*@
    978:    PEPSetStoppingTest - Specifies how to decide the termination of the outer
    979:    loop of the eigensolver.

    981:    Logically Collective on pep

    983:    Input Parameters:
    984: +  pep  - eigensolver context obtained from PEPCreate()
    985: -  stop - the type of stopping test

    987:    Options Database Keys:
    988: +  -pep_stop_basic - Sets the default stopping test
    989: -  -pep_stop_user  - Selects the user-defined stopping test

    991:    Note:
    992:    The parameter 'stop' can have one of these values
    993: +     PEP_STOP_BASIC - default stopping test
    994: -     PEP_STOP_USER  - function set by PEPSetStoppingTestFunction()

    996:    Level: advanced

    998: .seealso: PEPGetStoppingTest(), PEPSetStoppingTestFunction(), PEPSetConvergenceTest(), PEPStop
    999: @*/
    1000: PetscErrorCode PEPSetStoppingTest(PEP pep,PEPStop stop)
    1001: {
    1005:   switch (stop) {
    1006:     case PEP_STOP_BASIC: pep->stopping = PEPStoppingBasic; break;
    1007:     case PEP_STOP_USER:
    1008:       if (!pep->stoppinguser) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ORDER,"Must call PEPSetStoppingTestFunction() first");
    1009:       pep->stopping = pep->stoppinguser;
    1010:       break;
    1011:     default:
    1012:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'stop' value");
    1013:   }
    1014:   pep->stop = stop;
    1015:   return(0);
    1016: }

    1018: /*@
    1019:    PEPGetStoppingTest - Gets the method used to decide the termination of the outer
    1020:    loop of the eigensolver.

    1022:    Not Collective

    1024:    Input Parameters:
    1025: .  pep   - eigensolver context obtained from PEPCreate()

    1027:    Output Parameters:
    1028: .  stop  - the type of stopping test

    1030:    Level: advanced

    1032: .seealso: PEPSetStoppingTest(), PEPStop
    1033: @*/
    1034: PetscErrorCode PEPGetStoppingTest(PEP pep,PEPStop *stop)
    1035: {
    1039:   *stop = pep->stop;
    1040:   return(0);
    1041: }

    1043: /*@
    1044:    PEPSetScale - Specifies the scaling strategy to be used.

    1046:    Logically Collective on pep

    1048:    Input Parameters:
    1049: +  pep    - the eigensolver context
    1050: .  scale  - scaling strategy
    1051: .  alpha  - the scaling factor used in the scalar strategy
    1052: .  Dl     - the left diagonal matrix of the diagonal scaling algorithm
    1053: .  Dr     - the right diagonal matrix of the diagonal scaling algorithm
    1054: .  its    - number of iterations of the diagonal scaling algorithm
    1055: -  lambda - approximation to wanted eigenvalues (modulus)

    1057:    Options Database Keys:
    1058: +  -pep_scale <type> - scaling type, one of <none,scalar,diagonal,both>
    1059: .  -pep_scale_factor <alpha> - the scaling factor
    1060: .  -pep_scale_its <its> - number of iterations
    1061: -  -pep_scale_lambda <lambda> - approximation to eigenvalues

    1063:    Notes:
    1064:    There are two non-exclusive scaling strategies: scalar and diagonal.

    1066:    In the scalar strategy, scaling is applied to the eigenvalue, that is,
    1067:    mu = lambda/alpha is the new eigenvalue and all matrices are scaled
    1068:    accordingly. After solving the scaled problem, the original lambda is
    1069:    recovered. Parameter 'alpha' must be positive. Use PETSC_DEFAULT to let
    1070:    the solver compute a reasonable scaling factor.

    1072:    In the diagonal strategy, the solver works implicitly with matrix Dl*A*Dr,
    1073:    where Dl and Dr are appropriate diagonal matrices. This improves the accuracy
    1074:    of the computed results in some cases. The user may provide the Dr and Dl
    1075:    matrices represented as Vec objects storing diagonal elements. If not
    1076:    provided, these matrices are computed internally. This option requires
    1077:    that the polynomial coefficient matrices are of MATAIJ type.
    1078:    The parameter 'its' is the number of iterations performed by the method.
    1079:    Parameter 'lambda' must be positive. Use PETSC_DEFAULT or set lambda = 1.0 if
    1080:    no information about eigenvalues is available.

    1082:    Level: intermediate

    1084: .seealso: PEPGetScale()
    1085: @*/
    1086: PetscErrorCode PEPSetScale(PEP pep,PEPScale scale,PetscReal alpha,Vec Dl,Vec Dr,PetscInt its,PetscReal lambda)
    1087: {

    1093:   pep->scale = scale;
    1094:   if (scale==PEP_SCALE_SCALAR || scale==PEP_SCALE_BOTH) {
    1096:     if (alpha == PETSC_DEFAULT || alpha == PETSC_DECIDE) {
    1097:       pep->sfactor = 0.0;
    1098:       pep->sfactor_set = PETSC_FALSE;
    1099:     } else {
    1100:       if (alpha<=0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of alpha. Must be > 0");
    1101:       pep->sfactor = alpha;
    1102:       pep->sfactor_set = PETSC_TRUE;
    1103:     }
    1104:   }
    1105:   if (scale==PEP_SCALE_DIAGONAL || scale==PEP_SCALE_BOTH) {
    1106:     if (Dl) {
    1109:       PetscObjectReference((PetscObject)Dl);
    1110:       VecDestroy(&pep->Dl);
    1111:       pep->Dl = Dl;
    1112:     }
    1113:     if (Dr) {
    1116:       PetscObjectReference((PetscObject)Dr);
    1117:       VecDestroy(&pep->Dr);
    1118:       pep->Dr = Dr;
    1119:     }
    1122:     if (its==PETSC_DECIDE || its==PETSC_DEFAULT) pep->sits = 5;
    1123:     else pep->sits = its;
    1124:     if (lambda==PETSC_DECIDE || lambda==PETSC_DEFAULT) pep->slambda = 1.0;
    1125:     else if (lambda<=0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of lambda. Must be > 0");
    1126:     else pep->slambda = lambda;
    1127:   }
    1128:   pep->state = PEP_STATE_INITIAL;
    1129:   return(0);
    1130: }

    1132: /*@C
    1133:    PEPGetScale - Gets the scaling strategy used by the PEP object, and the
    1134:    associated parameters.

    1136:    Not Collectiv, but vectors are shared by all processors that share the PEP

    1138:    Input Parameter:
    1139: .  pep - the eigensolver context

    1141:    Output Parameters:
    1142: +  scale  - scaling strategy
    1143: .  alpha  - the scaling factor used in the scalar strategy
    1144: .  Dl     - the left diagonal matrix of the diagonal scaling algorithm
    1145: .  Dr     - the right diagonal matrix of the diagonal scaling algorithm
    1146: .  its    - number of iterations of the diagonal scaling algorithm
    1147: -  lambda - approximation to wanted eigenvalues (modulus)

    1149:    Level: intermediate

    1151:    Note:
    1152:    The user can specify NULL for any parameter that is not needed.

    1154:    If Dl or Dr were not set by the user, then the ones computed internally are
    1155:    returned (or a null pointer if called before PEPSetUp).

    1157: .seealso: PEPSetScale(), PEPSetUp()
    1158: @*/
    1159: PetscErrorCode PEPGetScale(PEP pep,PEPScale *scale,PetscReal *alpha,Vec *Dl,Vec *Dr,PetscInt *its,PetscReal *lambda)
    1160: {
    1163:   if (scale)  *scale  = pep->scale;
    1164:   if (alpha)  *alpha  = pep->sfactor;
    1165:   if (Dl)     *Dl     = pep->Dl;
    1166:   if (Dr)     *Dr     = pep->Dr;
    1167:   if (its)    *its    = pep->sits;
    1168:   if (lambda) *lambda = pep->slambda;
    1169:   return(0);
    1170: }

    1172: /*@
    1173:    PEPSetExtract - Specifies the extraction strategy to be used.

    1175:    Logically Collective on pep

    1177:    Input Parameters:
    1178: +  pep     - the eigensolver context
    1179: -  extract - extraction strategy

    1181:    Options Database Keys:
    1182: .  -pep_extract <type> - extraction type, one of <none,norm,residual,structured>

    1184:    Level: intermediate

    1186: .seealso: PEPGetExtract()
    1187: @*/
    1188: PetscErrorCode PEPSetExtract(PEP pep,PEPExtract extract)
    1189: {
    1193:   pep->extract = extract;
    1194:   return(0);
    1195: }

    1197: /*@
    1198:    PEPGetExtract - Gets the extraction strategy used by the PEP object.

    1200:    Not Collective

    1202:    Input Parameter:
    1203: .  pep - the eigensolver context

    1205:    Output Parameter:
    1206: .  extract - extraction strategy

    1208:    Level: intermediate

    1210: .seealso: PEPSetExtract(), PEPExtract
    1211: @*/
    1212: PetscErrorCode PEPGetExtract(PEP pep,PEPExtract *extract)
    1213: {
    1217:   *extract = pep->extract;
    1218:   return(0);
    1219: }

    1221: /*@
    1222:    PEPSetRefine - Specifies the refinement type (and options) to be used
    1223:    after the solve.

    1225:    Logically Collective on pep

    1227:    Input Parameters:
    1228: +  pep    - the polynomial eigensolver context
    1229: .  refine - refinement type
    1230: .  npart  - number of partitions of the communicator
    1231: .  tol    - the convergence tolerance
    1232: .  its    - maximum number of refinement iterations
    1233: -  scheme - which scheme to be used for solving the involved linear systems

    1235:    Options Database Keys:
    1236: +  -pep_refine <type> - refinement type, one of <none,simple,multiple>
    1237: .  -pep_refine_partitions <n> - the number of partitions
    1238: .  -pep_refine_tol <tol> - the tolerance
    1239: .  -pep_refine_its <its> - number of iterations
    1240: -  -pep_refine_scheme - to set the scheme for the linear solves

    1242:    Notes:
    1243:    By default, iterative refinement is disabled, since it may be very
    1244:    costly. There are two possible refinement strategies: simple and multiple.
    1245:    The simple approach performs iterative refinement on each of the
    1246:    converged eigenpairs individually, whereas the multiple strategy works
    1247:    with the invariant pair as a whole, refining all eigenpairs simultaneously.
    1248:    The latter may be required for the case of multiple eigenvalues.

    1250:    In some cases, especially when using direct solvers within the
    1251:    iterative refinement method, it may be helpful for improved scalability
    1252:    to split the communicator in several partitions. The npart parameter
    1253:    indicates how many partitions to use (defaults to 1).

    1255:    The tol and its parameters specify the stopping criterion. In the simple
    1256:    method, refinement continues until the residual of each eigenpair is
    1257:    below the tolerance (tol defaults to the PEP tol, but may be set to a
    1258:    different value). In contrast, the multiple method simply performs its
    1259:    refinement iterations (just one by default).

    1261:    The scheme argument is used to change the way in which linear systems are
    1262:    solved. Possible choices are: explicit, mixed block elimination (MBE),
    1263:    and Schur complement.

    1265:    Level: intermediate

    1267: .seealso: PEPGetRefine()
    1268: @*/
    1269: PetscErrorCode PEPSetRefine(PEP pep,PEPRefine refine,PetscInt npart,PetscReal tol,PetscInt its,PEPRefineScheme scheme)
    1270: {
    1272:   PetscMPIInt    size;

    1281:   pep->refine = refine;
    1282:   if (refine) {  /* process parameters only if not REFINE_NONE */
    1283:     if (npart!=pep->npart) {
    1284:       PetscSubcommDestroy(&pep->refinesubc);
    1285:       KSPDestroy(&pep->refineksp);
    1286:     }
    1287:     if (npart == PETSC_DEFAULT || npart == PETSC_DECIDE) {
    1288:       pep->npart = 1;
    1289:     } else {
    1290:       MPI_Comm_size(PetscObjectComm((PetscObject)pep),&size);
    1291:       if (npart<1 || npart>size) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of npart");
    1292:       pep->npart = npart;
    1293:     }
    1294:     if (tol == PETSC_DEFAULT || tol == PETSC_DECIDE) {
    1295:       pep->rtol = PETSC_DEFAULT;
    1296:     } else {
    1297:       if (tol<=0.0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    1298:       pep->rtol = tol;
    1299:     }
    1300:     if (its==PETSC_DECIDE || its==PETSC_DEFAULT) {
    1301:       pep->rits = PETSC_DEFAULT;
    1302:     } else {
    1303:       if (its<0) SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be >= 0");
    1304:       pep->rits = its;
    1305:     }
    1306:     pep->scheme = scheme;
    1307:   }
    1308:   pep->state = PEP_STATE_INITIAL;
    1309:   return(0);
    1310: }

    1312: /*@C
    1313:    PEPGetRefine - Gets the refinement strategy used by the PEP object, and the
    1314:    associated parameters.

    1316:    Not Collective

    1318:    Input Parameter:
    1319: .  pep - the polynomial eigensolver context

    1321:    Output Parameters:
    1322: +  refine - refinement type
    1323: .  npart  - number of partitions of the communicator
    1324: .  tol    - the convergence tolerance
    1325: .  its    - maximum number of refinement iterations
    1326: -  scheme - the scheme used for solving linear systems

    1328:    Level: intermediate

    1330:    Note:
    1331:    The user can specify NULL for any parameter that is not needed.

    1333: .seealso: PEPSetRefine()
    1334: @*/
    1335: PetscErrorCode PEPGetRefine(PEP pep,PEPRefine *refine,PetscInt *npart,PetscReal *tol,PetscInt *its,PEPRefineScheme *scheme)
    1336: {
    1339:   if (refine) *refine = pep->refine;
    1340:   if (npart)  *npart  = pep->npart;
    1341:   if (tol)    *tol    = pep->rtol;
    1342:   if (its)    *its    = pep->rits;
    1343:   if (scheme) *scheme = pep->scheme;
    1344:   return(0);
    1345: }

    1347: /*@C
    1348:    PEPSetOptionsPrefix - Sets the prefix used for searching for all
    1349:    PEP options in the database.

    1351:    Logically Collective on pep

    1353:    Input Parameters:
    1354: +  pep - the polynomial eigensolver context
    1355: -  prefix - the prefix string to prepend to all PEP option requests

    1357:    Notes:
    1358:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1359:    The first character of all runtime options is AUTOMATICALLY the
    1360:    hyphen.

    1362:    For example, to distinguish between the runtime options for two
    1363:    different PEP contexts, one could call
    1364: .vb
    1365:       PEPSetOptionsPrefix(pep1,"qeig1_")
    1366:       PEPSetOptionsPrefix(pep2,"qeig2_")
    1367: .ve

    1369:    Level: advanced

    1371: .seealso: PEPAppendOptionsPrefix(), PEPGetOptionsPrefix()
    1372: @*/
    1373: PetscErrorCode PEPSetOptionsPrefix(PEP pep,const char *prefix)
    1374: {

    1379:   if (!pep->st) { PEPGetST(pep,&pep->st); }
    1380:   STSetOptionsPrefix(pep->st,prefix);
    1381:   if (!pep->V) { PEPGetBV(pep,&pep->V); }
    1382:   BVSetOptionsPrefix(pep->V,prefix);
    1383:   if (!pep->ds) { PEPGetDS(pep,&pep->ds); }
    1384:   DSSetOptionsPrefix(pep->ds,prefix);
    1385:   if (!pep->rg) { PEPGetRG(pep,&pep->rg); }
    1386:   RGSetOptionsPrefix(pep->rg,prefix);
    1387:   PetscObjectSetOptionsPrefix((PetscObject)pep,prefix);
    1388:   return(0);
    1389: }

    1391: /*@C
    1392:    PEPAppendOptionsPrefix - Appends to the prefix used for searching for all
    1393:    PEP options in the database.

    1395:    Logically Collective on pep

    1397:    Input Parameters:
    1398: +  pep - the polynomial eigensolver context
    1399: -  prefix - the prefix string to prepend to all PEP option requests

    1401:    Notes:
    1402:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1403:    The first character of all runtime options is AUTOMATICALLY the hyphen.

    1405:    Level: advanced

    1407: .seealso: PEPSetOptionsPrefix(), PEPGetOptionsPrefix()
    1408: @*/
    1409: PetscErrorCode PEPAppendOptionsPrefix(PEP pep,const char *prefix)
    1410: {

    1415:   if (!pep->st) { PEPGetST(pep,&pep->st); }
    1416:   STAppendOptionsPrefix(pep->st,prefix);
    1417:   if (!pep->V) { PEPGetBV(pep,&pep->V); }
    1418:   BVAppendOptionsPrefix(pep->V,prefix);
    1419:   if (!pep->ds) { PEPGetDS(pep,&pep->ds); }
    1420:   DSAppendOptionsPrefix(pep->ds,prefix);
    1421:   if (!pep->rg) { PEPGetRG(pep,&pep->rg); }
    1422:   RGAppendOptionsPrefix(pep->rg,prefix);
    1423:   PetscObjectAppendOptionsPrefix((PetscObject)pep,prefix);
    1424:   return(0);
    1425: }

    1427: /*@C
    1428:    PEPGetOptionsPrefix - Gets the prefix used for searching for all
    1429:    PEP options in the database.

    1431:    Not Collective

    1433:    Input Parameters:
    1434: .  pep - the polynomial eigensolver context

    1436:    Output Parameters:
    1437: .  prefix - pointer to the prefix string used is returned

    1439:    Note:
    1440:    On the Fortran side, the user should pass in a string 'prefix' of
    1441:    sufficient length to hold the prefix.

    1443:    Level: advanced

    1445: .seealso: PEPSetOptionsPrefix(), PEPAppendOptionsPrefix()
    1446: @*/
    1447: PetscErrorCode PEPGetOptionsPrefix(PEP pep,const char *prefix[])
    1448: {

    1454:   PetscObjectGetOptionsPrefix((PetscObject)pep,prefix);
    1455:   return(0);
    1456: }