Date: 2024-12-02T08:57:37+00:00

Actual source code: pepopts.c
slepc-3.22.2 2024-12-02
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-, 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

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

     31:    Level: developer

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

     47:   PetscFunctionBegin;
     48:   PetscCall(PetscOptionsCreateViewer(PetscObjectComm((PetscObject)pep),((PetscObject)pep)->options,((PetscObject)pep)->prefix,opt,&viewer,&format,&flg));
     49:   if (!flg) PetscFunctionReturn(PETSC_SUCCESS);

     51:   PetscCall(PetscViewerGetType(viewer,&vtype));
     52:   PetscCall(SlepcMonitorMakeKey_Internal(name,vtype,format,key));
     53:   PetscCall(PetscFunctionListFind(PEPMonitorList,key,&mfunc));
     54:   PetscCheck(mfunc,PetscObjectComm((PetscObject)pep),PETSC_ERR_SUP,"Specified viewer and format not supported");
     55:   PetscCall(PetscFunctionListFind(PEPMonitorCreateList,key,&cfunc));
     56:   PetscCall(PetscFunctionListFind(PEPMonitorDestroyList,key,&dfunc));
     57:   if (!cfunc) cfunc = PetscViewerAndFormatCreate_Internal;
     58:   if (!dfunc) dfunc = PetscViewerAndFormatDestroy;

     60:   PetscCall((*cfunc)(viewer,format,ctx,&vf));
     61:   PetscCall(PetscViewerDestroy(&viewer));
     62:   PetscCall(PEPMonitorSet(pep,mfunc,vf,(PetscErrorCode(*)(void **))dfunc));
     63:   if (trackall) PetscCall(PEPSetTrackAll(pep,PETSC_TRUE));
     64:   PetscFunctionReturn(PETSC_SUCCESS);
     65: }

     67: /*@
     68:    PEPSetFromOptions - Sets PEP options from the options database.
     69:    This routine must be called before PEPSetUp() if the user is to be
     70:    allowed to set the solver type.

     72:    Collective

     74:    Input Parameters:
     75: .  pep - the polynomial eigensolver context

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

     80:    Level: beginner

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

     95:   PetscFunctionBegin;
     97:   PetscCall(PEPRegisterAll());
     98:   PetscObjectOptionsBegin((PetscObject)pep);
     99:     PetscCall(PetscOptionsFList("-pep_type","Polynomial eigensolver method","PEPSetType",PEPList,(char*)(((PetscObject)pep)->type_name?((PetscObject)pep)->type_name:PEPTOAR),type,sizeof(type),&flg));
    100:     if (flg) PetscCall(PEPSetType(pep,type));
    101:     else if (!((PetscObject)pep)->type_name) PetscCall(PEPSetType(pep,PEPTOAR));

    103:     PetscCall(PetscOptionsBoolGroupBegin("-pep_general","General polynomial eigenvalue problem","PEPSetProblemType",&flg));
    104:     if (flg) PetscCall(PEPSetProblemType(pep,PEP_GENERAL));
    105:     PetscCall(PetscOptionsBoolGroup("-pep_hermitian","Hermitian polynomial eigenvalue problem","PEPSetProblemType",&flg));
    106:     if (flg) PetscCall(PEPSetProblemType(pep,PEP_HERMITIAN));
    107:     PetscCall(PetscOptionsBoolGroup("-pep_hyperbolic","Hyperbolic polynomial eigenvalue problem","PEPSetProblemType",&flg));
    108:     if (flg) PetscCall(PEPSetProblemType(pep,PEP_HYPERBOLIC));
    109:     PetscCall(PetscOptionsBoolGroupEnd("-pep_gyroscopic","Gyroscopic polynomial eigenvalue problem","PEPSetProblemType",&flg));
    110:     if (flg) PetscCall(PEPSetProblemType(pep,PEP_GYROSCOPIC));

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

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

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

    137:     i = pep->max_it;
    138:     PetscCall(PetscOptionsInt("-pep_max_it","Maximum number of iterations","PEPSetTolerances",pep->max_it,&i,&flg1));
    139:     r = pep->tol;
    140:     PetscCall(PetscOptionsReal("-pep_tol","Tolerance","PEPSetTolerances",SlepcDefaultTol(pep->tol),&r,&flg2));
    141:     if (flg1 || flg2) PetscCall(PEPSetTolerances(pep,r,i));

    143:     PetscCall(PetscOptionsBoolGroupBegin("-pep_conv_rel","Relative error convergence test","PEPSetConvergenceTest",&flg));
    144:     if (flg) PetscCall(PEPSetConvergenceTest(pep,PEP_CONV_REL));
    145:     PetscCall(PetscOptionsBoolGroup("-pep_conv_norm","Convergence test relative to the matrix norms","PEPSetConvergenceTest",&flg));
    146:     if (flg) PetscCall(PEPSetConvergenceTest(pep,PEP_CONV_NORM));
    147:     PetscCall(PetscOptionsBoolGroup("-pep_conv_abs","Absolute error convergence test","PEPSetConvergenceTest",&flg));
    148:     if (flg) PetscCall(PEPSetConvergenceTest(pep,PEP_CONV_ABS));
    149:     PetscCall(PetscOptionsBoolGroupEnd("-pep_conv_user","User-defined convergence test","PEPSetConvergenceTest",&flg));
    150:     if (flg) PetscCall(PEPSetConvergenceTest(pep,PEP_CONV_USER));

    152:     PetscCall(PetscOptionsBoolGroupBegin("-pep_stop_basic","Stop iteration if all eigenvalues converged or max_it reached","PEPSetStoppingTest",&flg));
    153:     if (flg) PetscCall(PEPSetStoppingTest(pep,PEP_STOP_BASIC));
    154:     PetscCall(PetscOptionsBoolGroupEnd("-pep_stop_user","User-defined stopping test","PEPSetStoppingTest",&flg));
    155:     if (flg) PetscCall(PEPSetStoppingTest(pep,PEP_STOP_USER));

    157:     i = pep->nev;
    158:     PetscCall(PetscOptionsInt("-pep_nev","Number of eigenvalues to compute","PEPSetDimensions",pep->nev,&i,&flg1));
    159:     j = pep->ncv;
    160:     PetscCall(PetscOptionsInt("-pep_ncv","Number of basis vectors","PEPSetDimensions",pep->ncv,&j,&flg2));
    161:     k = pep->mpd;
    162:     PetscCall(PetscOptionsInt("-pep_mpd","Maximum dimension of projected problem","PEPSetDimensions",pep->mpd,&k,&flg3));
    163:     if (flg1 || flg2 || flg3) PetscCall(PEPSetDimensions(pep,i,j,k));

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

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

    188:     PetscCall(PetscOptionsScalar("-pep_target","Value of the target","PEPSetTarget",pep->target,&s,&flg));
    189:     if (flg) {
    190:       if (pep->which!=PEP_TARGET_REAL && pep->which!=PEP_TARGET_IMAGINARY) PetscCall(PEPSetWhichEigenpairs(pep,PEP_TARGET_MAGNITUDE));
    191:       PetscCall(PEPSetTarget(pep,s));
    192:     }

    194:     k = 2;
    195:     PetscCall(PetscOptionsRealArray("-pep_interval","Computational interval (two real values separated with a comma without spaces)","PEPSetInterval",array,&k,&flg));
    196:     if (flg) {
    197:       PetscCheck(k>1,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_SIZ,"Must pass two values in -pep_interval (comma-separated without spaces)");
    198:       PetscCall(PEPSetWhichEigenpairs(pep,PEP_ALL));
    199:       PetscCall(PEPSetInterval(pep,array[0],array[1]));
    200:     }

    202:     /* -----------------------------------------------------------------------*/
    203:     /*
    204:       Cancels all monitors hardwired into code before call to PEPSetFromOptions()
    205:     */
    206:     PetscCall(PetscOptionsBool("-pep_monitor_cancel","Remove any hardwired monitor routines","PEPMonitorCancel",PETSC_FALSE,&flg,&set));
    207:     if (set && flg) PetscCall(PEPMonitorCancel(pep));
    208:     PetscCall(PEPMonitorSetFromOptions(pep,"-pep_monitor","first_approximation",NULL,PETSC_FALSE));
    209:     PetscCall(PEPMonitorSetFromOptions(pep,"-pep_monitor_all","all_approximations",NULL,PETSC_TRUE));
    210:     PetscCall(PEPMonitorSetFromOptions(pep,"-pep_monitor_conv","convergence_history",NULL,PETSC_FALSE));

    212:     /* -----------------------------------------------------------------------*/
    213:     PetscCall(PetscOptionsName("-pep_view","Print detailed information on solver used","PEPView",&set));
    214:     PetscCall(PetscOptionsName("-pep_view_vectors","View computed eigenvectors","PEPVectorsView",&set));
    215:     PetscCall(PetscOptionsName("-pep_view_values","View computed eigenvalues","PEPValuesView",&set));
    216:     PetscCall(PetscOptionsName("-pep_converged_reason","Print reason for convergence, and number of iterations","PEPConvergedReasonView",&set));
    217:     PetscCall(PetscOptionsName("-pep_error_absolute","Print absolute errors of each eigenpair","PEPErrorView",&set));
    218:     PetscCall(PetscOptionsName("-pep_error_relative","Print relative errors of each eigenpair","PEPErrorView",&set));
    219:     PetscCall(PetscOptionsName("-pep_error_backward","Print backward errors of each eigenpair","PEPErrorView",&set));

    221:     PetscTryTypeMethod(pep,setfromoptions,PetscOptionsObject);
    222:     PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)pep,PetscOptionsObject));
    223:   PetscOptionsEnd();

    225:   if (!pep->V) PetscCall(PEPGetBV(pep,&pep->V));
    226:   PetscCall(BVSetFromOptions(pep->V));
    227:   if (!pep->rg) PetscCall(PEPGetRG(pep,&pep->rg));
    228:   PetscCall(RGSetFromOptions(pep->rg));
    229:   if (!pep->ds) PetscCall(PEPGetDS(pep,&pep->ds));
    230:   PetscCall(PEPSetDSType(pep));
    231:   PetscCall(DSSetFromOptions(pep->ds));
    232:   if (!pep->st) PetscCall(PEPGetST(pep,&pep->st));
    233:   PetscCall(PEPSetDefaultST(pep));
    234:   PetscCall(STSetFromOptions(pep->st));
    235:   if (!pep->refineksp) PetscCall(PEPRefineGetKSP(pep,&pep->refineksp));
    236:   PetscCall(KSPSetFromOptions(pep->refineksp));
    237:   PetscFunctionReturn(PETSC_SUCCESS);
    238: }

    240: /*@
    241:    PEPGetTolerances - Gets the tolerance and maximum iteration count used
    242:    by the PEP convergence tests.

    244:    Not Collective

    246:    Input Parameter:
    247: .  pep - the polynomial eigensolver context

    249:    Output Parameters:
    250: +  tol - the convergence tolerance
    251: -  maxits - maximum number of iterations

    253:    Notes:
    254:    The user can specify NULL for any parameter that is not needed.

    256:    Level: intermediate

    258: .seealso: PEPSetTolerances()
    259: @*/
    260: PetscErrorCode PEPGetTolerances(PEP pep,PetscReal *tol,PetscInt *maxits)
    261: {
    262:   PetscFunctionBegin;
    264:   if (tol)    *tol    = pep->tol;
    265:   if (maxits) *maxits = pep->max_it;
    266:   PetscFunctionReturn(PETSC_SUCCESS);
    267: }

    269: /*@
    270:    PEPSetTolerances - Sets the tolerance and maximum iteration count used
    271:    by the PEP convergence tests.

    273:    Logically Collective

    275:    Input Parameters:
    276: +  pep - the polynomial eigensolver context
    277: .  tol - the convergence tolerance
    278: -  maxits - maximum number of iterations to use

    280:    Options Database Keys:
    281: +  -pep_tol <tol> - Sets the convergence tolerance
    282: -  -pep_max_it <maxits> - Sets the maximum number of iterations allowed

    284:    Notes:
    285:    Use PETSC_CURRENT to retain the current value of any of the parameters.
    286:    Use PETSC_DETERMINE for either argument to assign a default value computed
    287:    internally (may be different in each solver).
    288:    For maxits use PETSC_UMLIMITED to indicate there is no upper bound on this value.

    290:    Level: intermediate

    292: .seealso: PEPGetTolerances()
    293: @*/
    294: PetscErrorCode PEPSetTolerances(PEP pep,PetscReal tol,PetscInt maxits)
    295: {
    296:   PetscFunctionBegin;
    300:   if (tol == (PetscReal)PETSC_DETERMINE) {
    301:     pep->tol   = PETSC_DETERMINE;
    302:     pep->state = PEP_STATE_INITIAL;
    303:   } else if (tol != (PetscReal)PETSC_CURRENT) {
    304:     PetscCheck(tol>0.0,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    305:     pep->tol = tol;
    306:   }
    307:   if (maxits == PETSC_DETERMINE) {
    308:     pep->max_it = PETSC_DETERMINE;
    309:     pep->state  = PEP_STATE_INITIAL;
    310:   } else if (maxits == PETSC_UNLIMITED) {
    311:     pep->max_it = PETSC_INT_MAX;
    312:   } else if (maxits != PETSC_CURRENT) {
    313:     PetscCheck(maxits>0,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of maxits. Must be > 0");
    314:     pep->max_it = maxits;
    315:   }
    316:   PetscFunctionReturn(PETSC_SUCCESS);
    317: }

    319: /*@
    320:    PEPGetDimensions - Gets the number of eigenvalues to compute
    321:    and the dimension of the subspace.

    323:    Not Collective

    325:    Input Parameter:
    326: .  pep - the polynomial eigensolver context

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

    333:    Notes:
    334:    The user can specify NULL for any parameter that is not needed.

    336:    Level: intermediate

    338: .seealso: PEPSetDimensions()
    339: @*/
    340: PetscErrorCode PEPGetDimensions(PEP pep,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
    341: {
    342:   PetscFunctionBegin;
    344:   if (nev) *nev = pep->nev;
    345:   if (ncv) *ncv = pep->ncv;
    346:   if (mpd) *mpd = pep->mpd;
    347:   PetscFunctionReturn(PETSC_SUCCESS);
    348: }

    350: /*@
    351:    PEPSetDimensions - Sets the number of eigenvalues to compute
    352:    and the dimension of the subspace.

    354:    Logically Collective

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

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

    367:    Notes:
    368:    Use PETSC_DETERMINE for ncv and mpd to assign a reasonably good value, which is
    369:    dependent on the solution method. For any of the arguments, use PETSC_CURRENT
    370:    to preserve the current value.

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

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

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

    384:    Level: intermediate

    386: .seealso: PEPGetDimensions(), PEPSetInterval(), PEPSTOARSetDimensions()
    387: @*/
    388: PetscErrorCode PEPSetDimensions(PEP pep,PetscInt nev,PetscInt ncv,PetscInt mpd)
    389: {
    390:   PetscFunctionBegin;
    395:   if (nev != PETSC_CURRENT) {
    396:     PetscCheck(nev>0,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
    397:     pep->nev = nev;
    398:   }
    399:   if (ncv == PETSC_DETERMINE) {
    400:     pep->ncv = PETSC_DETERMINE;
    401:   } else if (ncv != PETSC_CURRENT) {
    402:     PetscCheck(ncv>0,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
    403:     pep->ncv = ncv;
    404:   }
    405:   if (mpd == PETSC_DETERMINE) {
    406:     pep->mpd = PETSC_DETERMINE;
    407:   } else if (mpd != PETSC_CURRENT) {
    408:     PetscCheck(mpd>0,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
    409:     pep->mpd = mpd;
    410:   }
    411:   pep->state = PEP_STATE_INITIAL;
    412:   PetscFunctionReturn(PETSC_SUCCESS);
    413: }

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

    419:    Logically Collective

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

    425:    Options Database Keys:
    426: +   -pep_largest_magnitude - Sets largest eigenvalues in magnitude
    427: .   -pep_smallest_magnitude - Sets smallest eigenvalues in magnitude
    428: .   -pep_largest_real - Sets largest real parts
    429: .   -pep_smallest_real - Sets smallest real parts
    430: .   -pep_largest_imaginary - Sets largest imaginary parts
    431: .   -pep_smallest_imaginary - Sets smallest imaginary parts
    432: .   -pep_target_magnitude - Sets eigenvalues closest to target
    433: .   -pep_target_real - Sets real parts closest to target
    434: .   -pep_target_imaginary - Sets imaginary parts closest to target
    435: -   -pep_all - Sets all eigenvalues in an interval or region

    437:    Notes:
    438:    The parameter 'which' can have one of these values

    440: +     PEP_LARGEST_MAGNITUDE - largest eigenvalues in magnitude (default)
    441: .     PEP_SMALLEST_MAGNITUDE - smallest eigenvalues in magnitude
    442: .     PEP_LARGEST_REAL - largest real parts
    443: .     PEP_SMALLEST_REAL - smallest real parts
    444: .     PEP_LARGEST_IMAGINARY - largest imaginary parts
    445: .     PEP_SMALLEST_IMAGINARY - smallest imaginary parts
    446: .     PEP_TARGET_MAGNITUDE - eigenvalues closest to the target (in magnitude)
    447: .     PEP_TARGET_REAL - eigenvalues with real part closest to target
    448: .     PEP_TARGET_IMAGINARY - eigenvalues with imaginary part closest to target
    449: .     PEP_ALL - all eigenvalues contained in a given interval or region
    450: -     PEP_WHICH_USER - user defined ordering set with PEPSetEigenvalueComparison()

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

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

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

    462:    PEP_ALL is intended for use in combination with an interval (see
    463:    PEPSetInterval()), when all eigenvalues within the interval are requested,
    464:    and also for computing all eigenvalues in a region with the CISS solver.
    465:    In both cases, the number of eigenvalues is unknown, so the nev parameter
    466:    has a different sense, see PEPSetDimensions().

    468:    Level: intermediate

    470: .seealso: PEPGetWhichEigenpairs(), PEPSetTarget(), PEPSetInterval(),
    471:           PEPSetDimensions(), PEPSetEigenvalueComparison(), PEPWhich
    472: @*/
    473: PetscErrorCode PEPSetWhichEigenpairs(PEP pep,PEPWhich which)
    474: {
    475:   PetscFunctionBegin;
    478:   switch (which) {
    479:     case PEP_LARGEST_MAGNITUDE:
    480:     case PEP_SMALLEST_MAGNITUDE:
    481:     case PEP_LARGEST_REAL:
    482:     case PEP_SMALLEST_REAL:
    483:     case PEP_LARGEST_IMAGINARY:
    484:     case PEP_SMALLEST_IMAGINARY:
    485:     case PEP_TARGET_MAGNITUDE:
    486:     case PEP_TARGET_REAL:
    487: #if defined(PETSC_USE_COMPLEX)
    488:     case PEP_TARGET_IMAGINARY:
    489: #endif
    490:     case PEP_ALL:
    491:     case PEP_WHICH_USER:
    492:       if (pep->which != which) {
    493:         pep->state = PEP_STATE_INITIAL;
    494:         pep->which = which;
    495:       }
    496:       break;
    497: #if !defined(PETSC_USE_COMPLEX)
    498:     case PEP_TARGET_IMAGINARY:
    499:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_SUP,"PEP_TARGET_IMAGINARY can be used only with complex scalars");
    500: #endif
    501:     default:
    502:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'which' value");
    503:   }
    504:   PetscFunctionReturn(PETSC_SUCCESS);
    505: }

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

    511:     Not Collective

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

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

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

    522:     Level: intermediate

    524: .seealso: PEPSetWhichEigenpairs(), PEPWhich
    525: @*/
    526: PetscErrorCode PEPGetWhichEigenpairs(PEP pep,PEPWhich *which)
    527: {
    528:   PetscFunctionBegin;
    530:   PetscAssertPointer(which,2);
    531:   *which = pep->which;
    532:   PetscFunctionReturn(PETSC_SUCCESS);
    533: }

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

    539:    Logically Collective

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

    546:    Calling sequence of comp:
    547: $  PetscErrorCode comp(PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *res,void *ctx)
    548: +   ar     - real part of the 1st eigenvalue
    549: .   ai     - imaginary part of the 1st eigenvalue
    550: .   br     - real part of the 2nd eigenvalue
    551: .   bi     - imaginary part of the 2nd eigenvalue
    552: .   res    - result of comparison
    553: -   ctx    - optional context, as set by PEPSetEigenvalueComparison()

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

    561:    Level: advanced

    563: .seealso: PEPSetWhichEigenpairs(), PEPWhich
    564: @*/
    565: PetscErrorCode PEPSetEigenvalueComparison(PEP pep,PetscErrorCode (*comp)(PetscScalar ar,PetscScalar ai,PetscScalar br,PetscScalar bi,PetscInt *res,void *ctx),void* ctx)
    566: {
    567:   PetscFunctionBegin;
    569:   pep->sc->comparison    = comp;
    570:   pep->sc->comparisonctx = ctx;
    571:   pep->which             = PEP_WHICH_USER;
    572:   PetscFunctionReturn(PETSC_SUCCESS);
    573: }

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

    578:    Logically Collective

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

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

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

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

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

    603:    Level: intermediate

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

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

    623:    Not Collective

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

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

    631:    Level: intermediate

    633: .seealso: PEPSetProblemType(), PEPProblemType
    634: @*/
    635: PetscErrorCode PEPGetProblemType(PEP pep,PEPProblemType *type)
    636: {
    637:   PetscFunctionBegin;
    639:   PetscAssertPointer(type,2);
    640:   *type = pep->problem_type;
    641:   PetscFunctionReturn(PETSC_SUCCESS);
    642: }

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

    648:    Logically Collective

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

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

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

    664:    Level: intermediate

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

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

    680:    Not Collective

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

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

    688:    Level: intermediate

    690: .seealso: PEPSetBasis(), PEPBasis
    691: @*/
    692: PetscErrorCode PEPGetBasis(PEP pep,PEPBasis *basis)
    693: {
    694:   PetscFunctionBegin;
    696:   PetscAssertPointer(basis,2);
    697:   *basis = pep->basis;
    698:   PetscFunctionReturn(PETSC_SUCCESS);
    699: }

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

    705:    Logically Collective

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

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

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

    719:    Level: developer

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

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

    736:    Not Collective

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

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

    744:    Level: developer

    746: .seealso: PEPSetTrackAll()
    747: @*/
    748: PetscErrorCode PEPGetTrackAll(PEP pep,PetscBool *trackall)
    749: {
    750:   PetscFunctionBegin;
    752:   PetscAssertPointer(trackall,2);
    753:   *trackall = pep->trackall;
    754:   PetscFunctionReturn(PETSC_SUCCESS);
    755: }

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

    761:    Logically Collective

    763:    Input Parameters:
    764: +  pep     - eigensolver context obtained from PEPCreate()
    765: .  conv    - convergence test function, see PEPConvergenceTestFn for the calling sequence
    766: .  ctx     - context for private data for the convergence routine (may be NULL)
    767: -  destroy - a routine for destroying the context (may be NULL)

    769:    Note:
    770:    If the error estimate returned by the convergence test function is less than
    771:    the tolerance, then the eigenvalue is accepted as converged.

    773:    Level: advanced

    775: .seealso: PEPSetConvergenceTest(), PEPSetTolerances()
    776: @*/
    777: PetscErrorCode PEPSetConvergenceTestFunction(PEP pep,PEPConvergenceTestFn *conv,void* ctx,PetscErrorCode (*destroy)(void*))
    778: {
    779:   PetscFunctionBegin;
    781:   if (pep->convergeddestroy) PetscCall((*pep->convergeddestroy)(pep->convergedctx));
    782:   pep->convergeduser    = conv;
    783:   pep->convergeddestroy = destroy;
    784:   pep->convergedctx     = ctx;
    785:   if (conv == PEPConvergedRelative) pep->conv = PEP_CONV_REL;
    786:   else if (conv == PEPConvergedNorm) pep->conv = PEP_CONV_NORM;
    787:   else if (conv == PEPConvergedAbsolute) pep->conv = PEP_CONV_ABS;
    788:   else {
    789:     pep->conv      = PEP_CONV_USER;
    790:     pep->converged = pep->convergeduser;
    791:   }
    792:   PetscFunctionReturn(PETSC_SUCCESS);
    793: }

    795: /*@
    796:    PEPSetConvergenceTest - Specifies how to compute the error estimate
    797:    used in the convergence test.

    799:    Logically Collective

    801:    Input Parameters:
    802: +  pep  - eigensolver context obtained from PEPCreate()
    803: -  conv - the type of convergence test

    805:    Options Database Keys:
    806: +  -pep_conv_abs    - Sets the absolute convergence test
    807: .  -pep_conv_rel    - Sets the convergence test relative to the eigenvalue
    808: .  -pep_conv_norm   - Sets the convergence test relative to the matrix norms
    809: -  -pep_conv_user   - Selects the user-defined convergence test

    811:    Note:
    812:    The parameter 'conv' can have one of these values
    813: +     PEP_CONV_ABS    - absolute error ||r||
    814: .     PEP_CONV_REL    - error relative to the eigenvalue l, ||r||/|l|
    815: .     PEP_CONV_NORM   - error relative matrix norms, ||r||/sum_i(l^i*||A_i||)
    816: -     PEP_CONV_USER   - function set by PEPSetConvergenceTestFunction()

    818:    Level: intermediate

    820: .seealso: PEPGetConvergenceTest(), PEPSetConvergenceTestFunction(), PEPSetStoppingTest(), PEPConv
    821: @*/
    822: PetscErrorCode PEPSetConvergenceTest(PEP pep,PEPConv conv)
    823: {
    824:   PetscFunctionBegin;
    827:   switch (conv) {
    828:     case PEP_CONV_ABS:  pep->converged = PEPConvergedAbsolute; break;
    829:     case PEP_CONV_REL:  pep->converged = PEPConvergedRelative; break;
    830:     case PEP_CONV_NORM: pep->converged = PEPConvergedNorm; break;
    831:     case PEP_CONV_USER:
    832:       PetscCheck(pep->convergeduser,PetscObjectComm((PetscObject)pep),PETSC_ERR_ORDER,"Must call PEPSetConvergenceTestFunction() first");
    833:       pep->converged = pep->convergeduser;
    834:       break;
    835:     default:
    836:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'conv' value");
    837:   }
    838:   pep->conv = conv;
    839:   PetscFunctionReturn(PETSC_SUCCESS);
    840: }

    842: /*@
    843:    PEPGetConvergenceTest - Gets the method used to compute the error estimate
    844:    used in the convergence test.

    846:    Not Collective

    848:    Input Parameters:
    849: .  pep   - eigensolver context obtained from PEPCreate()

    851:    Output Parameters:
    852: .  conv  - the type of convergence test

    854:    Level: intermediate

    856: .seealso: PEPSetConvergenceTest(), PEPConv
    857: @*/
    858: PetscErrorCode PEPGetConvergenceTest(PEP pep,PEPConv *conv)
    859: {
    860:   PetscFunctionBegin;
    862:   PetscAssertPointer(conv,2);
    863:   *conv = pep->conv;
    864:   PetscFunctionReturn(PETSC_SUCCESS);
    865: }

    867: /*@C
    868:    PEPSetStoppingTestFunction - Sets a function to decide when to stop the outer
    869:    iteration of the eigensolver.

    871:    Logically Collective

    873:    Input Parameters:
    874: +  pep     - eigensolver context obtained from PEPCreate()
    875: .  stop    - stopping test function, see PEPStoppingTestFn for the calling sequence
    876: .  ctx     - context for private data for the stopping routine (may be NULL)
    877: -  destroy - a routine for destroying the context (may be NULL)

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

    885:    Level: advanced

    887: .seealso: PEPSetStoppingTest(), PEPStoppingBasic()
    888: @*/
    889: PetscErrorCode PEPSetStoppingTestFunction(PEP pep,PEPStoppingTestFn *stop,void* ctx,PetscErrorCode (*destroy)(void*))
    890: {
    891:   PetscFunctionBegin;
    893:   if (pep->stoppingdestroy) PetscCall((*pep->stoppingdestroy)(pep->stoppingctx));
    894:   pep->stoppinguser    = stop;
    895:   pep->stoppingdestroy = destroy;
    896:   pep->stoppingctx     = ctx;
    897:   if (stop == PEPStoppingBasic) pep->stop = PEP_STOP_BASIC;
    898:   else {
    899:     pep->stop     = PEP_STOP_USER;
    900:     pep->stopping = pep->stoppinguser;
    901:   }
    902:   PetscFunctionReturn(PETSC_SUCCESS);
    903: }

    905: /*@
    906:    PEPSetStoppingTest - Specifies how to decide the termination of the outer
    907:    loop of the eigensolver.

    909:    Logically Collective

    911:    Input Parameters:
    912: +  pep  - eigensolver context obtained from PEPCreate()
    913: -  stop - the type of stopping test

    915:    Options Database Keys:
    916: +  -pep_stop_basic - Sets the default stopping test
    917: -  -pep_stop_user  - Selects the user-defined stopping test

    919:    Note:
    920:    The parameter 'stop' can have one of these values
    921: +     PEP_STOP_BASIC - default stopping test
    922: -     PEP_STOP_USER  - function set by PEPSetStoppingTestFunction()

    924:    Level: advanced

    926: .seealso: PEPGetStoppingTest(), PEPSetStoppingTestFunction(), PEPSetConvergenceTest(), PEPStop
    927: @*/
    928: PetscErrorCode PEPSetStoppingTest(PEP pep,PEPStop stop)
    929: {
    930:   PetscFunctionBegin;
    933:   switch (stop) {
    934:     case PEP_STOP_BASIC: pep->stopping = PEPStoppingBasic; break;
    935:     case PEP_STOP_USER:
    936:       PetscCheck(pep->stoppinguser,PetscObjectComm((PetscObject)pep),PETSC_ERR_ORDER,"Must call PEPSetStoppingTestFunction() first");
    937:       pep->stopping = pep->stoppinguser;
    938:       break;
    939:     default:
    940:       SETERRQ(PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Invalid 'stop' value");
    941:   }
    942:   pep->stop = stop;
    943:   PetscFunctionReturn(PETSC_SUCCESS);
    944: }

    946: /*@
    947:    PEPGetStoppingTest - Gets the method used to decide the termination of the outer
    948:    loop of the eigensolver.

    950:    Not Collective

    952:    Input Parameters:
    953: .  pep   - eigensolver context obtained from PEPCreate()

    955:    Output Parameters:
    956: .  stop  - the type of stopping test

    958:    Level: advanced

    960: .seealso: PEPSetStoppingTest(), PEPStop
    961: @*/
    962: PetscErrorCode PEPGetStoppingTest(PEP pep,PEPStop *stop)
    963: {
    964:   PetscFunctionBegin;
    966:   PetscAssertPointer(stop,2);
    967:   *stop = pep->stop;
    968:   PetscFunctionReturn(PETSC_SUCCESS);
    969: }

    971: /*@
    972:    PEPSetScale - Specifies the scaling strategy to be used.

    974:    Collective

    976:    Input Parameters:
    977: +  pep    - the eigensolver context
    978: .  scale  - scaling strategy
    979: .  alpha  - the scaling factor used in the scalar strategy
    980: .  Dl     - the left diagonal matrix of the diagonal scaling algorithm
    981: .  Dr     - the right diagonal matrix of the diagonal scaling algorithm
    982: .  its    - number of iterations of the diagonal scaling algorithm
    983: -  lambda - approximation to wanted eigenvalues (modulus)

    985:    Options Database Keys:
    986: +  -pep_scale <type> - scaling type, one of <none,scalar,diagonal,both>
    987: .  -pep_scale_factor <alpha> - the scaling factor
    988: .  -pep_scale_its <its> - number of iterations
    989: -  -pep_scale_lambda <lambda> - approximation to eigenvalues

    991:    Notes:
    992:    There are two non-exclusive scaling strategies, scalar and diagonal.

    994:    In the scalar strategy, scaling is applied to the eigenvalue, that is,
    995:    mu = lambda/alpha is the new eigenvalue and all matrices are scaled
    996:    accordingly. After solving the scaled problem, the original lambda is
    997:    recovered. Parameter 'alpha' must be positive. Use PETSC_DETERMINE to let
    998:    the solver compute a reasonable scaling factor, and PETSC_CURRENT to
    999:    retain a previously set value.

    1001:    In the diagonal strategy, the solver works implicitly with matrix Dl*A*Dr,
    1002:    where Dl and Dr are appropriate diagonal matrices. This improves the accuracy
    1003:    of the computed results in some cases. The user may provide the Dr and Dl
    1004:    matrices represented as Vec objects storing diagonal elements. If not
    1005:    provided, these matrices are computed internally. This option requires
    1006:    that the polynomial coefficient matrices are of MATAIJ type.
    1007:    The parameter 'its' is the number of iterations performed by the method.
    1008:    Parameter 'lambda' must be positive. Use PETSC_DETERMINE or set lambda = 1.0
    1009:    if no information about eigenvalues is available. PETSC_CURRENT can also
    1010:    be used to leave its and lambda unchanged.

    1012:    Level: intermediate

    1014: .seealso: PEPGetScale()
    1015: @*/
    1016: PetscErrorCode PEPSetScale(PEP pep,PEPScale scale,PetscReal alpha,Vec Dl,Vec Dr,PetscInt its,PetscReal lambda)
    1017: {
    1018:   PetscFunctionBegin;
    1021:   pep->scale = scale;
    1022:   if (scale==PEP_SCALE_SCALAR || scale==PEP_SCALE_BOTH) {
    1024:     if (alpha == (PetscReal)PETSC_DETERMINE) {
    1025:       pep->sfactor = 0.0;
    1026:       pep->sfactor_set = PETSC_FALSE;
    1027:     } else if (alpha != (PetscReal)PETSC_CURRENT) {
    1028:       PetscCheck(alpha>0.0,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of alpha. Must be > 0");
    1029:       pep->sfactor = alpha;
    1030:       pep->sfactor_set = PETSC_TRUE;
    1031:     }
    1032:   }
    1033:   if (scale==PEP_SCALE_DIAGONAL || scale==PEP_SCALE_BOTH) {
    1034:     if (Dl) {
    1036:       PetscCheckSameComm(pep,1,Dl,4);
    1037:       PetscCall(PetscObjectReference((PetscObject)Dl));
    1038:       PetscCall(VecDestroy(&pep->Dl));
    1039:       pep->Dl = Dl;
    1040:     }
    1041:     if (Dr) {
    1043:       PetscCheckSameComm(pep,1,Dr,5);
    1044:       PetscCall(PetscObjectReference((PetscObject)Dr));
    1045:       PetscCall(VecDestroy(&pep->Dr));
    1046:       pep->Dr = Dr;
    1047:     }
    1050:     if (its==PETSC_DETERMINE) pep->sits = 5;
    1051:     else if (its!=PETSC_CURRENT) {
    1052:       PetscCheck(its>0,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be > 0");
    1053:       pep->sits = its;
    1054:     }
    1055:     if (lambda == (PetscReal)PETSC_DETERMINE) pep->slambda = 1.0;
    1056:     else if (lambda != (PetscReal)PETSC_CURRENT) {
    1057:       PetscCheck(lambda>0.0,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of lambda. Must be > 0");
    1058:       pep->slambda = lambda;
    1059:     }
    1060:   }
    1061:   pep->state = PEP_STATE_INITIAL;
    1062:   PetscFunctionReturn(PETSC_SUCCESS);
    1063: }

    1065: /*@
    1066:    PEPGetScale - Gets the scaling strategy used by the PEP object, and the
    1067:    associated parameters.

    1069:    Not Collective

    1071:    Input Parameter:
    1072: .  pep - the eigensolver context

    1074:    Output Parameters:
    1075: +  scale  - scaling strategy
    1076: .  alpha  - the scaling factor used in the scalar strategy
    1077: .  Dl     - the left diagonal matrix of the diagonal scaling algorithm
    1078: .  Dr     - the right diagonal matrix of the diagonal scaling algorithm
    1079: .  its    - number of iterations of the diagonal scaling algorithm
    1080: -  lambda - approximation to wanted eigenvalues (modulus)

    1082:    Level: intermediate

    1084:    Note:
    1085:    The user can specify NULL for any parameter that is not needed.

    1087:    If Dl or Dr were not set by the user, then the ones computed internally are
    1088:    returned (or a null pointer if called before PEPSetUp).

    1090: .seealso: PEPSetScale(), PEPSetUp()
    1091: @*/
    1092: PetscErrorCode PEPGetScale(PEP pep,PEPScale *scale,PetscReal *alpha,Vec *Dl,Vec *Dr,PetscInt *its,PetscReal *lambda)
    1093: {
    1094:   PetscFunctionBegin;
    1096:   if (scale)  *scale  = pep->scale;
    1097:   if (alpha)  *alpha  = pep->sfactor;
    1098:   if (Dl)     *Dl     = pep->Dl;
    1099:   if (Dr)     *Dr     = pep->Dr;
    1100:   if (its)    *its    = pep->sits;
    1101:   if (lambda) *lambda = pep->slambda;
    1102:   PetscFunctionReturn(PETSC_SUCCESS);
    1103: }

    1105: /*@
    1106:    PEPSetExtract - Specifies the extraction strategy to be used.

    1108:    Logically Collective

    1110:    Input Parameters:
    1111: +  pep     - the eigensolver context
    1112: -  extract - extraction strategy

    1114:    Options Database Keys:
    1115: .  -pep_extract <type> - extraction type, one of <none,norm,residual,structured>

    1117:    Level: intermediate

    1119: .seealso: PEPGetExtract()
    1120: @*/
    1121: PetscErrorCode PEPSetExtract(PEP pep,PEPExtract extract)
    1122: {
    1123:   PetscFunctionBegin;
    1126:   pep->extract = extract;
    1127:   PetscFunctionReturn(PETSC_SUCCESS);
    1128: }

    1130: /*@
    1131:    PEPGetExtract - Gets the extraction strategy used by the PEP object.

    1133:    Not Collective

    1135:    Input Parameter:
    1136: .  pep - the eigensolver context

    1138:    Output Parameter:
    1139: .  extract - extraction strategy

    1141:    Level: intermediate

    1143: .seealso: PEPSetExtract(), PEPExtract
    1144: @*/
    1145: PetscErrorCode PEPGetExtract(PEP pep,PEPExtract *extract)
    1146: {
    1147:   PetscFunctionBegin;
    1149:   PetscAssertPointer(extract,2);
    1150:   *extract = pep->extract;
    1151:   PetscFunctionReturn(PETSC_SUCCESS);
    1152: }

    1154: /*@
    1155:    PEPSetRefine - Specifies the refinement type (and options) to be used
    1156:    after the solve.

    1158:    Logically Collective

    1160:    Input Parameters:
    1161: +  pep    - the polynomial eigensolver context
    1162: .  refine - refinement type
    1163: .  npart  - number of partitions of the communicator
    1164: .  tol    - the convergence tolerance
    1165: .  its    - maximum number of refinement iterations
    1166: -  scheme - which scheme to be used for solving the involved linear systems

    1168:    Options Database Keys:
    1169: +  -pep_refine <type> - refinement type, one of <none,simple,multiple>
    1170: .  -pep_refine_partitions <n> - the number of partitions
    1171: .  -pep_refine_tol <tol> - the tolerance
    1172: .  -pep_refine_its <its> - number of iterations
    1173: -  -pep_refine_scheme - to set the scheme for the linear solves

    1175:    Notes:
    1176:    By default, iterative refinement is disabled, since it may be very
    1177:    costly. There are two possible refinement strategies, simple and multiple.
    1178:    The simple approach performs iterative refinement on each of the
    1179:    converged eigenpairs individually, whereas the multiple strategy works
    1180:    with the invariant pair as a whole, refining all eigenpairs simultaneously.
    1181:    The latter may be required for the case of multiple eigenvalues.

    1183:    In some cases, especially when using direct solvers within the
    1184:    iterative refinement method, it may be helpful for improved scalability
    1185:    to split the communicator in several partitions. The npart parameter
    1186:    indicates how many partitions to use (defaults to 1).

    1188:    The tol and its parameters specify the stopping criterion. In the simple
    1189:    method, refinement continues until the residual of each eigenpair is
    1190:    below the tolerance (tol defaults to the PEP tol, but may be set to a
    1191:    different value). In contrast, the multiple method simply performs its
    1192:    refinement iterations (just one by default).

    1194:    The scheme argument is used to change the way in which linear systems are
    1195:    solved. Possible choices are explicit, mixed block elimination (MBE),
    1196:    and Schur complement.

    1198:    Use PETSC_CURRENT to retain the current value of npart, tol or its. Use
    1199:    PETSC_DETERMINE to assign a default value.

    1201:    Level: intermediate

    1203: .seealso: PEPGetRefine()
    1204: @*/
    1205: PetscErrorCode PEPSetRefine(PEP pep,PEPRefine refine,PetscInt npart,PetscReal tol,PetscInt its,PEPRefineScheme scheme)
    1206: {
    1207:   PetscMPIInt    size;

    1209:   PetscFunctionBegin;
    1216:   pep->refine = refine;
    1217:   if (refine) {  /* process parameters only if not REFINE_NONE */
    1218:     if (npart!=pep->npart) {
    1219:       PetscCall(PetscSubcommDestroy(&pep->refinesubc));
    1220:       PetscCall(KSPDestroy(&pep->refineksp));
    1221:     }
    1222:     if (npart == PETSC_DETERMINE) {
    1223:       pep->npart = 1;
    1224:     } else if (npart != PETSC_CURRENT) {
    1225:       PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)pep),&size));
    1226:       PetscCheck(npart>0 && npart<=size,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of npart");
    1227:       pep->npart = npart;
    1228:     }
    1229:     if (tol == (PetscReal)PETSC_DETERMINE) {
    1230:       pep->rtol = PETSC_DETERMINE;
    1231:     } else if (tol != (PetscReal)PETSC_CURRENT) {
    1232:       PetscCheck(tol>0.0,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of tol. Must be > 0");
    1233:       pep->rtol = tol;
    1234:     }
    1235:     if (its==PETSC_DETERMINE) {
    1236:       pep->rits = PETSC_DETERMINE;
    1237:     } else if (its != PETSC_CURRENT) {
    1238:       PetscCheck(its>=0,PetscObjectComm((PetscObject)pep),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of its. Must be >= 0");
    1239:       pep->rits = its;
    1240:     }
    1241:     pep->scheme = scheme;
    1242:   }
    1243:   pep->state = PEP_STATE_INITIAL;
    1244:   PetscFunctionReturn(PETSC_SUCCESS);
    1245: }

    1247: /*@
    1248:    PEPGetRefine - Gets the refinement strategy used by the PEP object, and the
    1249:    associated parameters.

    1251:    Not Collective

    1253:    Input Parameter:
    1254: .  pep - the polynomial eigensolver context

    1256:    Output Parameters:
    1257: +  refine - refinement type
    1258: .  npart  - number of partitions of the communicator
    1259: .  tol    - the convergence tolerance
    1260: .  its    - maximum number of refinement iterations
    1261: -  scheme - the scheme used for solving linear systems

    1263:    Level: intermediate

    1265:    Note:
    1266:    The user can specify NULL for any parameter that is not needed.

    1268: .seealso: PEPSetRefine()
    1269: @*/
    1270: PetscErrorCode PEPGetRefine(PEP pep,PEPRefine *refine,PetscInt *npart,PetscReal *tol,PetscInt *its,PEPRefineScheme *scheme)
    1271: {
    1272:   PetscFunctionBegin;
    1274:   if (refine) *refine = pep->refine;
    1275:   if (npart)  *npart  = pep->npart;
    1276:   if (tol)    *tol    = pep->rtol;
    1277:   if (its)    *its    = pep->rits;
    1278:   if (scheme) *scheme = pep->scheme;
    1279:   PetscFunctionReturn(PETSC_SUCCESS);
    1280: }

    1282: /*@
    1283:    PEPSetOptionsPrefix - Sets the prefix used for searching for all
    1284:    PEP options in the database.

    1286:    Logically Collective

    1288:    Input Parameters:
    1289: +  pep - the polynomial eigensolver context
    1290: -  prefix - the prefix string to prepend to all PEP option requests

    1292:    Notes:
    1293:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1294:    The first character of all runtime options is AUTOMATICALLY the
    1295:    hyphen.

    1297:    For example, to distinguish between the runtime options for two
    1298:    different PEP contexts, one could call
    1299: .vb
    1300:       PEPSetOptionsPrefix(pep1,"qeig1_")
    1301:       PEPSetOptionsPrefix(pep2,"qeig2_")
    1302: .ve

    1304:    Level: advanced

    1306: .seealso: PEPAppendOptionsPrefix(), PEPGetOptionsPrefix()
    1307: @*/
    1308: PetscErrorCode PEPSetOptionsPrefix(PEP pep,const char *prefix)
    1309: {
    1310:   PetscFunctionBegin;
    1312:   if (!pep->st) PetscCall(PEPGetST(pep,&pep->st));
    1313:   PetscCall(STSetOptionsPrefix(pep->st,prefix));
    1314:   if (!pep->V) PetscCall(PEPGetBV(pep,&pep->V));
    1315:   PetscCall(BVSetOptionsPrefix(pep->V,prefix));
    1316:   if (!pep->ds) PetscCall(PEPGetDS(pep,&pep->ds));
    1317:   PetscCall(DSSetOptionsPrefix(pep->ds,prefix));
    1318:   if (!pep->rg) PetscCall(PEPGetRG(pep,&pep->rg));
    1319:   PetscCall(RGSetOptionsPrefix(pep->rg,prefix));
    1320:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)pep,prefix));
    1321:   PetscFunctionReturn(PETSC_SUCCESS);
    1322: }

    1324: /*@
    1325:    PEPAppendOptionsPrefix - Appends to the prefix used for searching for all
    1326:    PEP options in the database.

    1328:    Logically Collective

    1330:    Input Parameters:
    1331: +  pep - the polynomial eigensolver context
    1332: -  prefix - the prefix string to prepend to all PEP option requests

    1334:    Notes:
    1335:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    1336:    The first character of all runtime options is AUTOMATICALLY the hyphen.

    1338:    Level: advanced

    1340: .seealso: PEPSetOptionsPrefix(), PEPGetOptionsPrefix()
    1341: @*/
    1342: PetscErrorCode PEPAppendOptionsPrefix(PEP pep,const char *prefix)
    1343: {
    1344:   PetscFunctionBegin;
    1346:   if (!pep->st) PetscCall(PEPGetST(pep,&pep->st));
    1347:   PetscCall(STAppendOptionsPrefix(pep->st,prefix));
    1348:   if (!pep->V) PetscCall(PEPGetBV(pep,&pep->V));
    1349:   PetscCall(BVAppendOptionsPrefix(pep->V,prefix));
    1350:   if (!pep->ds) PetscCall(PEPGetDS(pep,&pep->ds));
    1351:   PetscCall(DSAppendOptionsPrefix(pep->ds,prefix));
    1352:   if (!pep->rg) PetscCall(PEPGetRG(pep,&pep->rg));
    1353:   PetscCall(RGAppendOptionsPrefix(pep->rg,prefix));
    1354:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)pep,prefix));
    1355:   PetscFunctionReturn(PETSC_SUCCESS);
    1356: }

    1358: /*@
    1359:    PEPGetOptionsPrefix - Gets the prefix used for searching for all
    1360:    PEP options in the database.

    1362:    Not Collective

    1364:    Input Parameters:
    1365: .  pep - the polynomial eigensolver context

    1367:    Output Parameters:
    1368: .  prefix - pointer to the prefix string used is returned

    1370:    Note:
    1371:    On the Fortran side, the user should pass in a string 'prefix' of
    1372:    sufficient length to hold the prefix.

    1374:    Level: advanced

    1376: .seealso: PEPSetOptionsPrefix(), PEPAppendOptionsPrefix()
    1377: @*/
    1378: PetscErrorCode PEPGetOptionsPrefix(PEP pep,const char *prefix[])
    1379: {
    1380:   PetscFunctionBegin;
    1382:   PetscAssertPointer(prefix,2);
    1383:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)pep,prefix));
    1384:   PetscFunctionReturn(PETSC_SUCCESS);
    1385: }