Actual source code: krylovschur.c
slepc-3.10.1 2018-10-23
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2018, Universitat Politecnica de Valencia, Spain

      6:    This file is part of SLEPc.
      7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
      8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      9: */
     10: /*
     11:    SLEPc eigensolver: "krylovschur"

     13:    Method: Krylov-Schur

     15:    Algorithm:

     17:        Single-vector Krylov-Schur method for non-symmetric problems,
     18:        including harmonic extraction.

     20:    References:

     22:        [1] "Krylov-Schur Methods in SLEPc", SLEPc Technical Report STR-7,
     23:            available at http://slepc.upv.es.

     25:        [2] G.W. Stewart, "A Krylov-Schur Algorithm for Large Eigenproblems",
     26:            SIAM J. Matrix Anal. App. 23(3):601-614, 2001.

     28:        [3] "Practical Implementation of Harmonic Krylov-Schur", SLEPc Technical
     29:             Report STR-9, available at http://slepc.upv.es.
     30: */

     32: #include <slepc/private/epsimpl.h>                /*I "slepceps.h" I*/
     33: #include "krylovschur.h"

     35: PetscErrorCode EPSGetArbitraryValues(EPS eps,PetscScalar *rr,PetscScalar *ri)
     36: {
     38:   PetscInt       i,newi,ld,n,l;
     39:   Vec            xr=eps->work[0],xi=eps->work[1];
     40:   PetscScalar    re,im,*Zr,*Zi,*X;

     43:   DSGetLeadingDimension(eps->ds,&ld);
     44:   DSGetDimensions(eps->ds,&n,NULL,&l,NULL,NULL);
     45:   for (i=l;i<n;i++) {
     46:     re = eps->eigr[i];
     47:     im = eps->eigi[i];
     48:     STBackTransform(eps->st,1,&re,&im);
     49:     newi = i;
     50:     DSVectors(eps->ds,DS_MAT_X,&newi,NULL);
     51:     DSGetArray(eps->ds,DS_MAT_X,&X);
     52:     Zr = X+i*ld;
     53:     if (newi==i+1) Zi = X+newi*ld;
     54:     else Zi = NULL;
     55:     EPSComputeRitzVector(eps,Zr,Zi,eps->V,xr,xi);
     56:     DSRestoreArray(eps->ds,DS_MAT_X,&X);
     57:     (*eps->arbitrary)(re,im,xr,xi,rr+i,ri+i,eps->arbitraryctx);
     58:   }
     59:   return(0);
     60: }

     62: static PetscErrorCode EstimateRange(Mat A,PetscReal *left,PetscReal *right)
     63: {
     65:   PetscInt       nconv;
     66:   PetscScalar    eig0;
     67:   EPS            eps;

     70:   *left = 0.0; *right = 0.0;
     71:   EPSCreate(PetscObjectComm((PetscObject)A),&eps);
     72:   EPSSetOptionsPrefix(eps,"eps_filter_");
     73:   EPSSetOperators(eps,A,NULL);
     74:   EPSSetProblemType(eps,EPS_HEP);
     75:   EPSSetTolerances(eps,1e-3,50);
     76:   EPSSetWhichEigenpairs(eps,EPS_SMALLEST_REAL);
     77:   EPSSolve(eps);
     78:   EPSGetConverged(eps,&nconv);
     79:   if (nconv>0) {
     80:     EPSGetEigenvalue(eps,0,&eig0,NULL);
     81:   } else eig0 = eps->eigr[0];
     82:   *left = PetscRealPart(eig0);
     83:   EPSSetWhichEigenpairs(eps,EPS_LARGEST_REAL);
     84:   EPSSolve(eps);
     85:   EPSGetConverged(eps,&nconv);
     86:   if (nconv>0) {
     87:     EPSGetEigenvalue(eps,0,&eig0,NULL);
     88:   } else eig0 = eps->eigr[0];
     89:   *right = PetscRealPart(eig0);
     90:   EPSDestroy(&eps);
     91:   return(0);
     92: }

     94: static PetscErrorCode EPSSetUp_KrylovSchur_Filter(EPS eps)
     95: {
     97:   SlepcSC        sc;
     98:   PetscReal      rleft,rright;
     99:   Mat            A;

    102:   if (eps->intb >= PETSC_MAX_REAL && eps->inta <= PETSC_MIN_REAL) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"The defined computational interval should have at least one of their sides bounded");
    103:   if (!eps->ishermitian) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Polynomial filter only available for symmetric/Hermitian eigenproblems");
    104:   if (eps->isgeneralized) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Polynomial filters not available for generalized eigenproblems");
    105:   if (eps->arbitrary) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Arbitrary selection of eigenpairs cannot be used with polynomial filters");
    106:   if (eps->tol==PETSC_DEFAULT) eps->tol = SLEPC_DEFAULT_TOL*1e-2;  /* use tighter tolerance */
    107:   STFilterSetInterval(eps->st,eps->inta,eps->intb);
    108:   STGetMatrix(eps->st,0,&A);
    109:   STFilterGetRange(eps->st,&rleft,&rright);
    110:   if (!rleft && !rright) {
    111:     EstimateRange(A,&rleft,&rright);
    112:     PetscInfo2(eps,"Setting eigenvalue range to [%g,%g]\n",(double)rleft,(double)rright);
    113:     STFilterSetRange(eps->st,rleft,rright);
    114:   }
    115:   if (!eps->ncv && eps->nev==1) eps->nev = 40;  /* user did not provide nev estimation */
    116:   EPSSetDimensions_Default(eps,eps->nev,&eps->ncv,&eps->mpd);
    117:   if (eps->ncv>eps->nev+eps->mpd) SETERRQ(PetscObjectComm((PetscObject)eps),1,"The value of ncv must not be larger than nev+mpd");
    118:   if (!eps->max_it) eps->max_it = PetscMax(100,2*eps->n/eps->ncv);

    120:   DSGetSlepcSC(eps->ds,&sc);
    121:   sc->rg            = NULL;
    122:   sc->comparison    = SlepcCompareLargestReal;
    123:   sc->comparisonctx = NULL;
    124:   sc->map           = NULL;
    125:   sc->mapobj        = NULL;
    126:   return(0);
    127: }

    129: PetscErrorCode EPSSetUp_KrylovSchur(EPS eps)
    130: {
    131:   PetscErrorCode    ierr;
    132:   PetscReal         eta;
    133:   PetscBool         isfilt=PETSC_FALSE;
    134:   BVOrthogType      otype;
    135:   BVOrthogBlockType obtype;
    136:   EPS_KRYLOVSCHUR   *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    137:   enum { EPS_KS_DEFAULT,EPS_KS_SYMM,EPS_KS_SLICE,EPS_KS_FILTER,EPS_KS_INDEF } variant;

    140:   /* spectrum slicing requires special treatment of default values */
    141:   if (eps->which==EPS_ALL) {
    142:     PetscObjectTypeCompare((PetscObject)eps->st,STFILTER,&isfilt);
    143:     if (isfilt) {
    144:       EPSSetUp_KrylovSchur_Filter(eps);
    145:     } else {
    146:       EPSSetUp_KrylovSchur_Slice(eps);
    147:     }
    148:   } else {
    149:     EPSSetDimensions_Default(eps,eps->nev,&eps->ncv,&eps->mpd);
    150:     if (eps->ncv>eps->nev+eps->mpd) SETERRQ(PetscObjectComm((PetscObject)eps),1,"The value of ncv must not be larger than nev+mpd");
    151:     if (!eps->max_it) eps->max_it = PetscMax(100,2*eps->n/eps->ncv);
    152:     if (!eps->which) { EPSSetWhichEigenpairs_Default(eps); }
    153:   }
    154:   if (!ctx->lock && eps->mpd<eps->ncv) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Should not use mpd parameter in non-locking variant");

    156:   if (eps->isgeneralized && eps->ishermitian && !eps->ispositive && eps->arbitrary) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Arbitrary selection of eigenpairs not implemented for indefinite problems");
    157:   if (eps->ishermitian && eps->ispositive && (eps->which==EPS_LARGEST_IMAGINARY || eps->which==EPS_SMALLEST_IMAGINARY)) SETERRQ(PetscObjectComm((PetscObject)eps),1,"Wrong value of eps->which");

    159:   if (!eps->extraction) {
    160:     EPSSetExtraction(eps,EPS_RITZ);
    161:   } else if (eps->extraction!=EPS_RITZ && eps->extraction!=EPS_HARMONIC) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type");
    162:   if (eps->extraction==EPS_HARMONIC && ctx->lock) { PetscInfo(eps,"Locking was requested but will be deactivated since is not supported with harmonic extraction\n"); }

    164:   if (!ctx->keep) ctx->keep = 0.5;

    166:   EPSAllocateSolution(eps,1);
    167:   EPS_SetInnerProduct(eps);
    168:   if (eps->arbitrary) {
    169:     EPSSetWorkVecs(eps,2);
    170:   } else if (eps->ishermitian && !eps->ispositive){
    171:     EPSSetWorkVecs(eps,1);
    172:   }

    174:   /* dispatch solve method */
    175:   if (eps->ishermitian) {
    176:     if (eps->which==EPS_ALL) {
    177:       if (eps->isgeneralized && !eps->ispositive) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Spectrum slicing not implemented for indefinite problems");
    178:       else variant = isfilt? EPS_KS_FILTER: EPS_KS_SLICE;
    179:     } else if (eps->isgeneralized && !eps->ispositive) {
    180:       variant = EPS_KS_INDEF;
    181:     } else {
    182:       switch (eps->extraction) {
    183:         case EPS_RITZ:     variant = EPS_KS_SYMM; break;
    184:         case EPS_HARMONIC: variant = EPS_KS_DEFAULT; break;
    185:         default: SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type");
    186:       }
    187:     }
    188:   } else {
    189:     switch (eps->extraction) {
    190:       case EPS_RITZ:     variant = EPS_KS_DEFAULT; break;
    191:       case EPS_HARMONIC: variant = EPS_KS_DEFAULT; break;
    192:       default: SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type");
    193:     }
    194:   }
    195:   switch (variant) {
    196:     case EPS_KS_DEFAULT:
    197:       eps->ops->solve = EPSSolve_KrylovSchur_Default;
    198:       eps->ops->computevectors = EPSComputeVectors_Schur;
    199:       DSSetType(eps->ds,DSNHEP);
    200:       DSAllocate(eps->ds,eps->ncv+1);
    201:       break;
    202:     case EPS_KS_SYMM:
    203:     case EPS_KS_FILTER:
    204:       eps->ops->solve = EPSSolve_KrylovSchur_Symm;
    205:       eps->ops->computevectors = EPSComputeVectors_Hermitian;
    206:       DSSetType(eps->ds,DSHEP);
    207:       DSSetCompact(eps->ds,PETSC_TRUE);
    208:       DSSetExtraRow(eps->ds,PETSC_TRUE);
    209:       DSAllocate(eps->ds,eps->ncv+1);
    210:       break;
    211:     case EPS_KS_SLICE:
    212:       if (eps->stopping!=EPSStoppingBasic) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Spectrum slicing does not support user-defined stopping test");
    213:       eps->ops->solve = EPSSolve_KrylovSchur_Slice;
    214:       eps->ops->computevectors = EPSComputeVectors_Slice;
    215:       break;
    216:     case EPS_KS_INDEF:
    217:       eps->ops->solve = EPSSolve_KrylovSchur_Indefinite;
    218:       eps->ops->computevectors = EPSComputeVectors_Indefinite;
    219:       DSSetType(eps->ds,DSGHIEP);
    220:       DSSetCompact(eps->ds,PETSC_TRUE);
    221:       DSAllocate(eps->ds,eps->ncv+1);
    222:       /* force reorthogonalization for pseudo-Lanczos */
    223:       BVGetOrthogonalization(eps->V,&otype,NULL,&eta,&obtype);
    224:       BVSetOrthogonalization(eps->V,otype,BV_ORTHOG_REFINE_ALWAYS,eta,obtype);
    225:       break;
    226:     default: SETERRQ(PetscObjectComm((PetscObject)eps),1,"Unexpected error");
    227:   }
    228:   return(0);
    229: }

    231: PetscErrorCode EPSSolve_KrylovSchur_Default(EPS eps)
    232: {
    233:   PetscErrorCode  ierr;
    234:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    235:   PetscInt        i,j,*pj,k,l,nv,ld,nconv;
    236:   Mat             U;
    237:   PetscScalar     *S,*Q,*g;
    238:   PetscReal       beta,gamma=1.0;
    239:   PetscBool       breakdown,harmonic;

    242:   DSGetLeadingDimension(eps->ds,&ld);
    243:   harmonic = (eps->extraction==EPS_HARMONIC || eps->extraction==EPS_REFINED_HARMONIC)?PETSC_TRUE:PETSC_FALSE;
    244:   if (harmonic) { PetscMalloc1(ld,&g); }
    245:   if (eps->arbitrary) pj = &j;
    246:   else pj = NULL;

    248:   /* Get the starting Arnoldi vector */
    249:   EPSGetStartVector(eps,0,NULL);
    250:   l = 0;

    252:   /* Restart loop */
    253:   while (eps->reason == EPS_CONVERGED_ITERATING) {
    254:     eps->its++;

    256:     /* Compute an nv-step Arnoldi factorization */
    257:     nv = PetscMin(eps->nconv+eps->mpd,eps->ncv);
    258:     DSGetArray(eps->ds,DS_MAT_A,&S);
    259:     EPSBasicArnoldi(eps,PETSC_FALSE,S,ld,eps->nconv+l,&nv,&beta,&breakdown);
    260:     DSRestoreArray(eps->ds,DS_MAT_A,&S);
    261:     DSSetDimensions(eps->ds,nv,0,eps->nconv,eps->nconv+l);
    262:     if (l==0) {
    263:       DSSetState(eps->ds,DS_STATE_INTERMEDIATE);
    264:     } else {
    265:       DSSetState(eps->ds,DS_STATE_RAW);
    266:     }
    267:     BVSetActiveColumns(eps->V,eps->nconv,nv);

    269:     /* Compute translation of Krylov decomposition if harmonic extraction used */
    270:     if (harmonic) {
    271:       DSTranslateHarmonic(eps->ds,eps->target,beta,PETSC_FALSE,g,&gamma);
    272:     }

    274:     /* Solve projected problem */
    275:     DSSolve(eps->ds,eps->eigr,eps->eigi);
    276:     if (eps->arbitrary) {
    277:       EPSGetArbitraryValues(eps,eps->rr,eps->ri);
    278:       j=1;
    279:     }
    280:     DSSort(eps->ds,eps->eigr,eps->eigi,eps->rr,eps->ri,pj);
    281:     DSSynchronize(eps->ds,eps->eigr,eps->eigi);

    283:     /* Check convergence */
    284:     EPSKrylovConvergence(eps,PETSC_FALSE,eps->nconv,nv-eps->nconv,beta,gamma,&k);
    285:     (*eps->stopping)(eps,eps->its,eps->max_it,k,eps->nev,&eps->reason,eps->stoppingctx);
    286:     nconv = k;

    288:     /* Update l */
    289:     if (eps->reason != EPS_CONVERGED_ITERATING || breakdown || k==nv) l = 0;
    290:     else {
    291:       l = PetscMax(1,(PetscInt)((nv-k)*ctx->keep));
    292: #if !defined(PETSC_USE_COMPLEX)
    293:       DSGetArray(eps->ds,DS_MAT_A,&S);
    294:       if (S[k+l+(k+l-1)*ld] != 0.0) {
    295:         if (k+l<nv-1) l = l+1;
    296:         else l = l-1;
    297:       }
    298:       DSRestoreArray(eps->ds,DS_MAT_A,&S);
    299: #endif
    300:     }
    301:     if ((!ctx->lock || harmonic) && l>0) { l += k; k = 0; } /* non-locking variant: reset no. of converged pairs */

    303:     if (eps->reason == EPS_CONVERGED_ITERATING) {
    304:       if (breakdown || k==nv) {
    305:         /* Start a new Arnoldi factorization */
    306:         PetscInfo2(eps,"Breakdown in Krylov-Schur method (it=%D norm=%g)\n",eps->its,(double)beta);
    307:         if (k<eps->nev) {
    308:           EPSGetStartVector(eps,k,&breakdown);
    309:           if (breakdown) {
    310:             eps->reason = EPS_DIVERGED_BREAKDOWN;
    311:             PetscInfo(eps,"Unable to generate more start vectors\n");
    312:           }
    313:         }
    314:       } else {
    315:         /* Undo translation of Krylov decomposition */
    316:         if (harmonic) {
    317:           DSSetDimensions(eps->ds,nv,0,k,l);
    318:           DSTranslateHarmonic(eps->ds,0.0,beta,PETSC_TRUE,g,&gamma);
    319:           /* gamma u^ = u - U*g~ */
    320:           BVMultColumn(eps->V,-1.0,1.0,nv,g);
    321:           BVScaleColumn(eps->V,nv,1.0/gamma);
    322:         }
    323:         /* Prepare the Rayleigh quotient for restart */
    324:         DSGetArray(eps->ds,DS_MAT_A,&S);
    325:         DSGetArray(eps->ds,DS_MAT_Q,&Q);
    326:         for (i=k;i<k+l;i++) {
    327:           S[k+l+i*ld] = Q[nv-1+i*ld]*beta*gamma;
    328:         }
    329:         DSRestoreArray(eps->ds,DS_MAT_A,&S);
    330:         DSRestoreArray(eps->ds,DS_MAT_Q,&Q);
    331:       }
    332:     }
    333:     /* Update the corresponding vectors V(:,idx) = V*Q(:,idx) */
    334:     DSGetMat(eps->ds,DS_MAT_Q,&U);
    335:     BVMultInPlace(eps->V,U,eps->nconv,k+l);
    336:     MatDestroy(&U);

    338:     if (eps->reason == EPS_CONVERGED_ITERATING && !breakdown) {
    339:       BVCopyColumn(eps->V,nv,k+l);
    340:     }
    341:     eps->nconv = k;
    342:     EPSMonitor(eps,eps->its,nconv,eps->eigr,eps->eigi,eps->errest,nv);
    343:   }

    345:   if (harmonic) { PetscFree(g); }
    346:   /* truncate Schur decomposition and change the state to raw so that
    347:      DSVectors() computes eigenvectors from scratch */
    348:   DSSetDimensions(eps->ds,eps->nconv,0,0,0);
    349:   DSSetState(eps->ds,DS_STATE_RAW);
    350:   return(0);
    351: }

    353: static PetscErrorCode EPSKrylovSchurSetRestart_KrylovSchur(EPS eps,PetscReal keep)
    354: {
    355:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    358:   if (keep==PETSC_DEFAULT) ctx->keep = 0.5;
    359:   else {
    360:     if (keep<0.1 || keep>0.9) SETERRQ1(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"The keep argument %g must be in the range [0.1,0.9]",keep);
    361:     ctx->keep = keep;
    362:   }
    363:   return(0);
    364: }

    366: /*@
    367:    EPSKrylovSchurSetRestart - Sets the restart parameter for the Krylov-Schur
    368:    method, in particular the proportion of basis vectors that must be kept
    369:    after restart.

    371:    Logically Collective on EPS

    373:    Input Parameters:
    374: +  eps - the eigenproblem solver context
    375: -  keep - the number of vectors to be kept at restart

    377:    Options Database Key:
    378: .  -eps_krylovschur_restart - Sets the restart parameter

    380:    Notes:
    381:    Allowed values are in the range [0.1,0.9]. The default is 0.5.

    383:    Level: advanced

    385: .seealso: EPSKrylovSchurGetRestart()
    386: @*/
    387: PetscErrorCode EPSKrylovSchurSetRestart(EPS eps,PetscReal keep)
    388: {

    394:   PetscTryMethod(eps,"EPSKrylovSchurSetRestart_C",(EPS,PetscReal),(eps,keep));
    395:   return(0);
    396: }

    398: static PetscErrorCode EPSKrylovSchurGetRestart_KrylovSchur(EPS eps,PetscReal *keep)
    399: {
    400:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    403:   *keep = ctx->keep;
    404:   return(0);
    405: }

    407: /*@
    408:    EPSKrylovSchurGetRestart - Gets the restart parameter used in the
    409:    Krylov-Schur method.

    411:    Not Collective

    413:    Input Parameter:
    414: .  eps - the eigenproblem solver context

    416:    Output Parameter:
    417: .  keep - the restart parameter

    419:    Level: advanced

    421: .seealso: EPSKrylovSchurSetRestart()
    422: @*/
    423: PetscErrorCode EPSKrylovSchurGetRestart(EPS eps,PetscReal *keep)
    424: {

    430:   PetscUseMethod(eps,"EPSKrylovSchurGetRestart_C",(EPS,PetscReal*),(eps,keep));
    431:   return(0);
    432: }

    434: static PetscErrorCode EPSKrylovSchurSetLocking_KrylovSchur(EPS eps,PetscBool lock)
    435: {
    436:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    439:   ctx->lock = lock;
    440:   return(0);
    441: }

    443: /*@
    444:    EPSKrylovSchurSetLocking - Choose between locking and non-locking variants of
    445:    the Krylov-Schur method.

    447:    Logically Collective on EPS

    449:    Input Parameters:
    450: +  eps  - the eigenproblem solver context
    451: -  lock - true if the locking variant must be selected

    453:    Options Database Key:
    454: .  -eps_krylovschur_locking - Sets the locking flag

    456:    Notes:
    457:    The default is to lock converged eigenpairs when the method restarts.
    458:    This behaviour can be changed so that all directions are kept in the
    459:    working subspace even if already converged to working accuracy (the
    460:    non-locking variant).

    462:    Level: advanced

    464: .seealso: EPSKrylovSchurGetLocking()
    465: @*/
    466: PetscErrorCode EPSKrylovSchurSetLocking(EPS eps,PetscBool lock)
    467: {

    473:   PetscTryMethod(eps,"EPSKrylovSchurSetLocking_C",(EPS,PetscBool),(eps,lock));
    474:   return(0);
    475: }

    477: static PetscErrorCode EPSKrylovSchurGetLocking_KrylovSchur(EPS eps,PetscBool *lock)
    478: {
    479:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    482:   *lock = ctx->lock;
    483:   return(0);
    484: }

    486: /*@
    487:    EPSKrylovSchurGetLocking - Gets the locking flag used in the Krylov-Schur
    488:    method.

    490:    Not Collective

    492:    Input Parameter:
    493: .  eps - the eigenproblem solver context

    495:    Output Parameter:
    496: .  lock - the locking flag

    498:    Level: advanced

    500: .seealso: EPSKrylovSchurSetLocking()
    501: @*/
    502: PetscErrorCode EPSKrylovSchurGetLocking(EPS eps,PetscBool *lock)
    503: {

    509:   PetscUseMethod(eps,"EPSKrylovSchurGetLocking_C",(EPS,PetscBool*),(eps,lock));
    510:   return(0);
    511: }

    513: static PetscErrorCode EPSKrylovSchurSetPartitions_KrylovSchur(EPS eps,PetscInt npart)
    514: {
    515:   PetscErrorCode  ierr;
    516:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    517:   PetscMPIInt     size;

    520:   if (ctx->npart!=npart) {
    521:     if (ctx->commset) { PetscSubcommDestroy(&ctx->subc); }
    522:     EPSDestroy(&ctx->eps);
    523:   }
    524:   if (npart == PETSC_DEFAULT || npart == PETSC_DECIDE) {
    525:     ctx->npart = 1;
    526:   } else {
    527:     MPI_Comm_size(PetscObjectComm((PetscObject)eps),&size);
    528:     if (npart<1 || npart>size) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of npart");
    529:     ctx->npart = npart;
    530:   }
    531:   eps->state = EPS_STATE_INITIAL;
    532:   return(0);
    533: }

    535: /*@
    536:    EPSKrylovSchurSetPartitions - Sets the number of partitions for the
    537:    case of doing spectrum slicing for a computational interval with the
    538:    communicator split in several sub-communicators.

    540:    Logically Collective on EPS

    542:    Input Parameters:
    543: +  eps   - the eigenproblem solver context
    544: -  npart - number of partitions

    546:    Options Database Key:
    547: .  -eps_krylovschur_partitions <npart> - Sets the number of partitions

    549:    Notes:
    550:    By default, npart=1 so all processes in the communicator participate in
    551:    the processing of the whole interval. If npart>1 then the interval is
    552:    divided into npart subintervals, each of them being processed by a
    553:    subset of processes.

    555:    The interval is split proportionally unless the separation points are
    556:    specified with EPSKrylovSchurSetSubintervals().

    558:    Level: advanced

    560: .seealso: EPSKrylovSchurSetSubintervals(), EPSSetInterval()
    561: @*/
    562: PetscErrorCode EPSKrylovSchurSetPartitions(EPS eps,PetscInt npart)
    563: {

    569:   PetscTryMethod(eps,"EPSKrylovSchurSetPartitions_C",(EPS,PetscInt),(eps,npart));
    570:   return(0);
    571: }

    573: static PetscErrorCode EPSKrylovSchurGetPartitions_KrylovSchur(EPS eps,PetscInt *npart)
    574: {
    575:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    578:   *npart  = ctx->npart;
    579:   return(0);
    580: }

    582: /*@
    583:    EPSKrylovSchurGetPartitions - Gets the number of partitions of the
    584:    communicator in case of spectrum slicing.

    586:    Not Collective

    588:    Input Parameter:
    589: .  eps - the eigenproblem solver context

    591:    Output Parameter:
    592: .  npart - number of partitions

    594:    Level: advanced

    596: .seealso: EPSKrylovSchurSetPartitions()
    597: @*/
    598: PetscErrorCode EPSKrylovSchurGetPartitions(EPS eps,PetscInt *npart)
    599: {

    605:   PetscUseMethod(eps,"EPSKrylovSchurGetPartitions_C",(EPS,PetscInt*),(eps,npart));
    606:   return(0);
    607: }

    609: static PetscErrorCode EPSKrylovSchurSetDetectZeros_KrylovSchur(EPS eps,PetscBool detect)
    610: {
    611:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    614:   ctx->detect = detect;
    615:   eps->state  = EPS_STATE_INITIAL;
    616:   return(0);
    617: }

    619: /*@
    620:    EPSKrylovSchurSetDetectZeros - Sets a flag to enforce detection of
    621:    zeros during the factorizations throughout the spectrum slicing computation.

    623:    Logically Collective on EPS

    625:    Input Parameters:
    626: +  eps    - the eigenproblem solver context
    627: -  detect - check for zeros

    629:    Options Database Key:
    630: .  -eps_krylovschur_detect_zeros - Check for zeros; this takes an optional
    631:    bool value (0/1/no/yes/true/false)

    633:    Notes:
    634:    A zero in the factorization indicates that a shift coincides with an eigenvalue.

    636:    This flag is turned off by default, and may be necessary in some cases,
    637:    especially when several partitions are being used. This feature currently
    638:    requires an external package for factorizations with support for zero
    639:    detection, e.g. MUMPS.

    641:    Level: advanced

    643: .seealso: EPSKrylovSchurSetPartitions(), EPSSetInterval()
    644: @*/
    645: PetscErrorCode EPSKrylovSchurSetDetectZeros(EPS eps,PetscBool detect)
    646: {

    652:   PetscTryMethod(eps,"EPSKrylovSchurSetDetectZeros_C",(EPS,PetscBool),(eps,detect));
    653:   return(0);
    654: }

    656: static PetscErrorCode EPSKrylovSchurGetDetectZeros_KrylovSchur(EPS eps,PetscBool *detect)
    657: {
    658:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    661:   *detect = ctx->detect;
    662:   return(0);
    663: }

    665: /*@
    666:    EPSKrylovSchurGetDetectZeros - Gets the flag that enforces zero detection
    667:    in spectrum slicing.

    669:    Not Collective

    671:    Input Parameter:
    672: .  eps - the eigenproblem solver context

    674:    Output Parameter:
    675: .  detect - whether zeros detection is enforced during factorizations

    677:    Level: advanced

    679: .seealso: EPSKrylovSchurSetDetectZeros()
    680: @*/
    681: PetscErrorCode EPSKrylovSchurGetDetectZeros(EPS eps,PetscBool *detect)
    682: {

    688:   PetscUseMethod(eps,"EPSKrylovSchurGetDetectZeros_C",(EPS,PetscBool*),(eps,detect));
    689:   return(0);
    690: }

    692: static PetscErrorCode EPSKrylovSchurSetDimensions_KrylovSchur(EPS eps,PetscInt nev,PetscInt ncv,PetscInt mpd)
    693: {
    694:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    697:   if (nev<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
    698:   ctx->nev = nev;
    699:   if (ncv == PETSC_DECIDE || ncv == PETSC_DEFAULT) {
    700:     ctx->ncv = 0;
    701:   } else {
    702:     if (ncv<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
    703:     ctx->ncv = ncv;
    704:   }
    705:   if (mpd == PETSC_DECIDE || mpd == PETSC_DEFAULT) {
    706:     ctx->mpd = 0;
    707:   } else {
    708:     if (mpd<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
    709:     ctx->mpd = mpd;
    710:   }
    711:   eps->state = EPS_STATE_INITIAL;
    712:   return(0);
    713: }

    715: /*@
    716:    EPSKrylovSchurSetDimensions - Sets the dimensions used for each subsolve
    717:    step in case of doing spectrum slicing for a computational interval.
    718:    The meaning of the parameters is the same as in EPSSetDimensions().

    720:    Logically Collective on EPS

    722:    Input Parameters:
    723: +  eps - the eigenproblem solver context
    724: .  nev - number of eigenvalues to compute
    725: .  ncv - the maximum dimension of the subspace to be used by the subsolve
    726: -  mpd - the maximum dimension allowed for the projected problem

    728:    Options Database Key:
    729: +  -eps_krylovschur_nev <nev> - Sets the number of eigenvalues
    730: .  -eps_krylovschur_ncv <ncv> - Sets the dimension of the subspace
    731: -  -eps_krylovschur_mpd <mpd> - Sets the maximum projected dimension

    733:    Level: advanced

    735: .seealso: EPSKrylovSchurGetDimensions(), EPSSetDimensions(), EPSSetInterval()
    736: @*/
    737: PetscErrorCode EPSKrylovSchurSetDimensions(EPS eps,PetscInt nev,PetscInt ncv,PetscInt mpd)
    738: {

    746:   PetscTryMethod(eps,"EPSKrylovSchurSetDimensions_C",(EPS,PetscInt,PetscInt,PetscInt),(eps,nev,ncv,mpd));
    747:   return(0);
    748: }

    750: static PetscErrorCode EPSKrylovSchurGetDimensions_KrylovSchur(EPS eps,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
    751: {
    752:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    755:   if (nev) *nev = ctx->nev;
    756:   if (ncv) *ncv = ctx->ncv;
    757:   if (mpd) *mpd = ctx->mpd;
    758:   return(0);
    759: }

    761: /*@
    762:    EPSKrylovSchurGetDimensions - Gets the dimensions used for each subsolve
    763:    step in case of doing spectrum slicing for a computational interval.

    765:    Not Collective

    767:    Input Parameter:
    768: .  eps - the eigenproblem solver context

    770:    Output Parameters:
    771: +  nev - number of eigenvalues to compute
    772: .  ncv - the maximum dimension of the subspace to be used by the subsolve
    773: -  mpd - the maximum dimension allowed for the projected problem

    775:    Level: advanced

    777: .seealso: EPSKrylovSchurSetDimensions()
    778: @*/
    779: PetscErrorCode EPSKrylovSchurGetDimensions(EPS eps,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
    780: {

    785:   PetscUseMethod(eps,"EPSKrylovSchurGetDimensions_C",(EPS,PetscInt*,PetscInt*,PetscInt*),(eps,nev,ncv,mpd));
    786:   return(0);
    787: }

    789: static PetscErrorCode EPSKrylovSchurSetSubintervals_KrylovSchur(EPS eps,PetscReal* subint)
    790: {
    791:   PetscErrorCode  ierr;
    792:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    793:   PetscInt        i;

    796:   if (subint[0]!=eps->inta || subint[ctx->npart]!=eps->intb) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"First and last values must match the endpoints of EPSSetInterval()");
    797:   for (i=0;i<ctx->npart;i++) if (subint[i]>subint[i+1]) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"Array must contain values in ascending order");
    798:   if (ctx->subintervals) { PetscFree(ctx->subintervals); }
    799:   PetscMalloc1(ctx->npart+1,&ctx->subintervals);
    800:   for (i=0;i<ctx->npart+1;i++) ctx->subintervals[i] = subint[i];
    801:   ctx->subintset = PETSC_TRUE;
    802:   eps->state = EPS_STATE_INITIAL;
    803:   return(0);
    804: }

    806: /*@C
    807:    EPSKrylovSchurSetSubintervals - Sets the points that delimit the
    808:    subintervals to be used in spectrum slicing with several partitions.

    810:    Logically Collective on EPS

    812:    Input Parameters:
    813: +  eps    - the eigenproblem solver context
    814: -  subint - array of real values specifying subintervals

    816:    Notes:
    817:    This function must be called after EPSKrylovSchurSetPartitions(). For npart
    818:    partitions, the argument subint must contain npart+1 real values sorted in
    819:    ascending order: subint_0, subint_1, ..., subint_npart, where the first
    820:    and last values must coincide with the interval endpoints set with
    821:    EPSSetInterval().

    823:    The subintervals are then defined by two consecutive points: [subint_0,subint_1],
    824:    [subint_1,subint_2], and so on.

    826:    Level: advanced

    828: .seealso: EPSKrylovSchurSetPartitions(), EPSKrylovSchurGetSubintervals(), EPSSetInterval()
    829: @*/
    830: PetscErrorCode EPSKrylovSchurSetSubintervals(EPS eps,PetscReal *subint)
    831: {

    836:   PetscTryMethod(eps,"EPSKrylovSchurSetSubintervals_C",(EPS,PetscReal*),(eps,subint));
    837:   return(0);
    838: }

    840: static PetscErrorCode EPSKrylovSchurGetSubintervals_KrylovSchur(EPS eps,PetscReal **subint)
    841: {
    842:   PetscErrorCode  ierr;
    843:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    844:   PetscInt        i;

    847:   if (!ctx->subintset) {
    848:     if (!eps->state) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Must call EPSSetUp() first");
    849:     if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    850:   }
    851:   PetscMalloc1(ctx->npart+1,subint);
    852:   for (i=0;i<=ctx->npart;i++) (*subint)[i] = ctx->subintervals[i];
    853:   return(0);
    854: }

    856: /*@C
    857:    EPSKrylovSchurGetSubintervals - Returns the points that delimit the
    858:    subintervals used in spectrum slicing with several partitions.

    860:    Logically Collective on EPS

    862:    Input Parameter:
    863: .  eps    - the eigenproblem solver context

    865:    Output Parameter:
    866: .  subint - array of real values specifying subintervals

    868:    Notes:
    869:    If the user passed values with EPSKrylovSchurSetSubintervals(), then the
    870:    same values are returned. Otherwise, the values computed internally are
    871:    obtained.

    873:    This function is only available for spectrum slicing runs.

    875:    The returned array has length npart+1 (see EPSKrylovSchurGetPartitions())
    876:    and should be freed by the user.

    878:    Fortran Notes:
    879:    The calling sequence from Fortran is
    880: .vb
    881:    EPSKrylovSchurGetSubintervals(eps,subint,ierr)
    882:    double precision subint(npart+1) output
    883: .ve

    885:    Level: advanced

    887: .seealso: EPSKrylovSchurSetSubintervals(), EPSKrylovSchurGetPartitions(), EPSSetInterval()
    888: @*/
    889: PetscErrorCode EPSKrylovSchurGetSubintervals(EPS eps,PetscReal **subint)
    890: {

    896:   PetscUseMethod(eps,"EPSKrylovSchurGetSubintervals_C",(EPS,PetscReal**),(eps,subint));
    897:   return(0);
    898: }

    900: static PetscErrorCode EPSKrylovSchurGetInertias_KrylovSchur(EPS eps,PetscInt *n,PetscReal **shifts,PetscInt **inertias)
    901: {
    902:   PetscErrorCode  ierr;
    903:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    904:   PetscInt        i,numsh;
    905:   EPS_SR          sr = ctx->sr;

    908:   if (!eps->state) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Must call EPSSetUp() first");
    909:   if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    910:   switch (eps->state) {
    911:   case EPS_STATE_INITIAL:
    912:     break;
    913:   case EPS_STATE_SETUP:
    914:     numsh = ctx->npart+1;
    915:     if (n) *n = numsh;
    916:     if (shifts) {
    917:       PetscMalloc1(numsh,shifts);
    918:       (*shifts)[0] = eps->inta;
    919:       if (ctx->npart==1) (*shifts)[1] = eps->intb;
    920:       else for (i=1;i<numsh;i++) (*shifts)[i] = ctx->subintervals[i];
    921:     }
    922:     if (inertias) {
    923:       PetscMalloc1(numsh,inertias);
    924:       (*inertias)[0] = (sr->dir==1)?sr->inertia0:sr->inertia1;
    925:       if (ctx->npart==1) (*inertias)[1] = (sr->dir==1)?sr->inertia1:sr->inertia0;
    926:       else for (i=1;i<numsh;i++) (*inertias)[i] = (*inertias)[i-1]+ctx->nconv_loc[i-1];
    927:     }
    928:     break;
    929:   case EPS_STATE_SOLVED:
    930:   case EPS_STATE_EIGENVECTORS:
    931:     numsh = ctx->nshifts;
    932:     if (n) *n = numsh;
    933:     if (shifts) {
    934:       PetscMalloc1(numsh,shifts);
    935:       for (i=0;i<numsh;i++) (*shifts)[i] = ctx->shifts[i];
    936:     }
    937:     if (inertias) {
    938:       PetscMalloc1(numsh,inertias);
    939:       for (i=0;i<numsh;i++) (*inertias)[i] = ctx->inertias[i];
    940:     }
    941:     break;
    942:   }
    943:   return(0);
    944: }

    946: /*@C
    947:    EPSKrylovSchurGetInertias - Gets the values of the shifts and their
    948:    corresponding inertias in case of doing spectrum slicing for a
    949:    computational interval.

    951:    Not Collective

    953:    Input Parameter:
    954: .  eps - the eigenproblem solver context

    956:    Output Parameters:
    957: +  n        - number of shifts, including the endpoints of the interval
    958: .  shifts   - the values of the shifts used internally in the solver
    959: -  inertias - the values of the inertia in each shift

    961:    Notes:
    962:    If called after EPSSolve(), all shifts used internally by the solver are
    963:    returned (including both endpoints and any intermediate ones). If called
    964:    before EPSSolve() and after EPSSetUp() then only the information of the
    965:    endpoints of subintervals is available.

    967:    This function is only available for spectrum slicing runs.

    969:    The returned arrays should be freed by the user. Can pass NULL in any of
    970:    the two arrays if not required.

    972:    Fortran Notes:
    973:    The calling sequence from Fortran is
    974: .vb
    975:    EPSKrylovSchurGetInertias(eps,n,shifts,inertias,ierr)
    976:    integer n
    977:    double precision shifts(*)
    978:    integer inertias(*)
    979: .ve
    980:    The arrays should be at least of length n. The value of n can be determined
    981:    by an initial call
    982: .vb
    983:    EPSKrylovSchurGetInertias(eps,n,PETSC_NULL_REAL,PETSC_NULL_INTEGER,ierr)
    984: .ve

    986:    Level: advanced

    988: .seealso: EPSSetInterval(), EPSKrylovSchurSetSubintervals()
    989: @*/
    990: PetscErrorCode EPSKrylovSchurGetInertias(EPS eps,PetscInt *n,PetscReal **shifts,PetscInt **inertias)
    991: {

    997:   PetscUseMethod(eps,"EPSKrylovSchurGetInertias_C",(EPS,PetscInt*,PetscReal**,PetscInt**),(eps,n,shifts,inertias));
    998:   return(0);
    999: }

    1001: static PetscErrorCode EPSKrylovSchurGetSubcommInfo_KrylovSchur(EPS eps,PetscInt *k,PetscInt *n,Vec *v)
    1002: {
    1003:   PetscErrorCode  ierr;
    1004:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    1005:   EPS_SR          sr = ((EPS_KRYLOVSCHUR*)ctx->eps->data)->sr;

    1008:   if (!eps->state) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Must call EPSSetUp() first");
    1009:   if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    1010:   if (k) *k = (ctx->npart==1)? 0: ctx->subc->color;
    1011:   if (n) *n = sr->numEigs;
    1012:   if (v) {
    1013:     BVCreateVec(sr->V,v);
    1014:   }
    1015:   return(0);
    1016: }

    1018: /*@C
    1019:    EPSKrylovSchurGetSubcommInfo - Gets information related to the case of
    1020:    doing spectrum slicing for a computational interval with multiple
    1021:    communicators.

    1023:    Collective on the subcommunicator (if v is given)

    1025:    Input Parameter:
    1026: .  eps - the eigenproblem solver context

    1028:    Output Parameters:
    1029: +  k - index of the subinterval for the calling process
    1030: .  n - number of eigenvalues found in the k-th subinterval
    1031: -  v - a vector owned by processes in the subcommunicator with dimensions
    1032:        compatible for locally computed eigenvectors (or NULL)

    1034:    Notes:
    1035:    This function is only available for spectrum slicing runs.

    1037:    The returned Vec should be destroyed by the user.

    1039:    Level: advanced

    1041: .seealso: EPSSetInterval(), EPSKrylovSchurSetPartitions(), EPSKrylovSchurGetSubcommPairs()
    1042: @*/
    1043: PetscErrorCode EPSKrylovSchurGetSubcommInfo(EPS eps,PetscInt *k,PetscInt *n,Vec *v)
    1044: {

    1049:   PetscUseMethod(eps,"EPSKrylovSchurGetSubcommInfo_C",(EPS,PetscInt*,PetscInt*,Vec*),(eps,k,n,v));
    1050:   return(0);
    1051: }

    1053: static PetscErrorCode EPSKrylovSchurGetSubcommPairs_KrylovSchur(EPS eps,PetscInt i,PetscScalar *eig,Vec v)
    1054: {
    1055:   PetscErrorCode  ierr;
    1056:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    1057:   EPS_SR          sr = ((EPS_KRYLOVSCHUR*)ctx->eps->data)->sr;

    1060:   EPSCheckSolved(eps,1);
    1061:   if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    1062:   if (i<0 || i>=sr->numEigs) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Argument 2 out of range");
    1063:   if (eig) *eig = sr->eigr[sr->perm[i]];
    1064:   if (v) { BVCopyVec(sr->V,sr->perm[i],v); }
    1065:   return(0);
    1066: }

    1068: /*@
    1069:    EPSKrylovSchurGetSubcommPairs - Gets the i-th eigenpair stored
    1070:    internally in the subcommunicator to which the calling process belongs.

    1072:    Collective on the subcommunicator (if v is given)

    1074:    Input Parameter:
    1075: +  eps - the eigenproblem solver context
    1076: -  i   - index of the solution

    1078:    Output Parameters:
    1079: +  eig - the eigenvalue
    1080: -  v   - the eigenvector

    1082:    Notes:
    1083:    It is allowed to pass NULL for v if the eigenvector is not required.
    1084:    Otherwise, the caller must provide a valid Vec objects, i.e.,
    1085:    it must be created by the calling program with EPSKrylovSchurGetSubcommInfo().

    1087:    The index i should be a value between 0 and n-1, where n is the number of
    1088:    vectors in the local subinterval, see EPSKrylovSchurGetSubcommInfo().

    1090:    Level: advanced

    1092: .seealso: EPSSetInterval(), EPSKrylovSchurSetPartitions(), EPSKrylovSchurGetSubcommInfo(), EPSKrylovSchurGetSubcommMats()
    1093: @*/
    1094: PetscErrorCode EPSKrylovSchurGetSubcommPairs(EPS eps,PetscInt i,PetscScalar *eig,Vec v)
    1095: {

    1101:   PetscUseMethod(eps,"EPSKrylovSchurGetSubcommPairs_C",(EPS,PetscInt,PetscScalar*,Vec),(eps,i,eig,v));
    1102:   return(0);
    1103: }

    1105: static PetscErrorCode EPSKrylovSchurGetSubcommMats_KrylovSchur(EPS eps,Mat *A,Mat *B)
    1106: {
    1107:   PetscErrorCode  ierr;
    1108:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    1111:   if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    1112:   if (!eps->state) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Must call EPSSetUp() first");
    1113:   EPSGetOperators(ctx->eps,A,B);
    1114:   return(0);
    1115: }

    1117: /*@C
    1118:    EPSKrylovSchurGetSubcommMats - Gets the eigenproblem matrices stored
    1119:    internally in the subcommunicator to which the calling process belongs.

    1121:    Collective on the subcommunicator

    1123:    Input Parameter:
    1124: .  eps - the eigenproblem solver context

    1126:    Output Parameters:
    1127: +  A  - the matrix associated with the eigensystem
    1128: -  B  - the second matrix in the case of generalized eigenproblems

    1130:    Notes:
    1131:    This is the analog of EPSGetOperators(), but returns the matrices distributed
    1132:    differently (in the subcommunicator rather than in the parent communicator).

    1134:    These matrices should not be modified by the user.

    1136:    Level: advanced

    1138: .seealso: EPSSetInterval(), EPSKrylovSchurSetPartitions(), EPSKrylovSchurGetSubcommInfo()
    1139: @*/
    1140: PetscErrorCode EPSKrylovSchurGetSubcommMats(EPS eps,Mat *A,Mat *B)
    1141: {

    1146:   PetscTryMethod(eps,"EPSKrylovSchurGetSubcommMats_C",(EPS,Mat*,Mat*),(eps,A,B));
    1147:   return(0);
    1148: }

    1150: static PetscErrorCode EPSKrylovSchurUpdateSubcommMats_KrylovSchur(EPS eps,PetscScalar a,PetscScalar ap,Mat Au,PetscScalar b,PetscScalar bp, Mat Bu,MatStructure str,PetscBool globalup)
    1151: {
    1152:   PetscErrorCode  ierr;
    1153:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data,*subctx;
    1154:   Mat             A,B=NULL,Ag,Bg=NULL;
    1155:   PetscBool       reuse=PETSC_TRUE;

    1158:   if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    1159:   if (!eps->state) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Must call EPSSetUp() first");
    1160:   EPSGetOperators(eps,&Ag,&Bg);
    1161:   EPSGetOperators(ctx->eps,&A,&B);

    1163:   MatScale(A,a);
    1164:   if (Au) {
    1165:     MatAXPY(A,ap,Au,str);
    1166:   }
    1167:   if (B) MatScale(B,b);
    1168:   if (Bu) {
    1169:     MatAXPY(B,bp,Bu,str);
    1170:   }
    1171:   EPSSetOperators(ctx->eps,A,B);

    1173:   /* Update stored matrix state */
    1174:   subctx = (EPS_KRYLOVSCHUR*)ctx->eps->data;
    1175:   PetscObjectStateGet((PetscObject)A,&subctx->Astate);
    1176:   if (B) { PetscObjectStateGet((PetscObject)B,&subctx->Bstate); }

    1178:   /* Update matrices in the parent communicator if requested by user */
    1179:   if (globalup) {
    1180:     if (ctx->npart>1) {
    1181:       if (!ctx->isrow) {
    1182:         MatGetOwnershipIS(Ag,&ctx->isrow,&ctx->iscol);
    1183:         reuse = PETSC_FALSE;
    1184:       }
    1185:       if (str==DIFFERENT_NONZERO_PATTERN) reuse = PETSC_FALSE;
    1186:       if (ctx->submata && !reuse) {
    1187:         MatDestroyMatrices(1,&ctx->submata);
    1188:       }
    1189:       MatCreateSubMatrices(A,1,&ctx->isrow,&ctx->iscol,(reuse)?MAT_REUSE_MATRIX:MAT_INITIAL_MATRIX,&ctx->submata);
    1190:       MatCreateMPIMatConcatenateSeqMat(((PetscObject)Ag)->comm,ctx->submata[0],PETSC_DECIDE,MAT_REUSE_MATRIX,&Ag);
    1191:       if (B) {
    1192:         if (ctx->submatb && !reuse) {
    1193:           MatDestroyMatrices(1,&ctx->submatb);
    1194:         }
    1195:         MatCreateSubMatrices(B,1,&ctx->isrow,&ctx->iscol,(reuse)?MAT_REUSE_MATRIX:MAT_INITIAL_MATRIX,&ctx->submatb);
    1196:         MatCreateMPIMatConcatenateSeqMat(((PetscObject)Bg)->comm,ctx->submatb[0],PETSC_DECIDE,MAT_REUSE_MATRIX,&Bg);
    1197:       }
    1198:     }
    1199:     PetscObjectStateGet((PetscObject)Ag,&ctx->Astate);
    1200:     if (Bg) { PetscObjectStateGet((PetscObject)Bg,&ctx->Bstate); }
    1201:   }
    1202:   EPSSetOperators(eps,Ag,Bg);
    1203:   return(0);
    1204: }

    1206: /*@
    1207:    EPSKrylovSchurUpdateSubcommMats - Update the eigenproblem matrices stored
    1208:    internally in the subcommunicator to which the calling process belongs.

    1210:    Collective on EPS

    1212:    Input Parameters:
    1213: +  eps - the eigenproblem solver context
    1214: .  s   - scalar that multiplies the existing A matrix
    1215: .  a   - scalar used in the axpy operation on A
    1216: .  Au  - matrix used in the axpy operation on A
    1217: .  t   - scalar that multiplies the existing B matrix
    1218: .  b   - scalar used in the axpy operation on B
    1219: .  Bu  - matrix used in the axpy operation on B
    1220: .  str - structure flag
    1221: -  globalup - flag indicating if global matrices must be updated

    1223:    Notes:
    1224:    This function modifies the eigenproblem matrices at the subcommunicator level,
    1225:    and optionally updates the global matrices in the parent communicator. The updates
    1226:    are expressed as A <-- s*A + a*Au,  B <-- t*B + b*Bu.

    1228:    It is possible to update one of the matrices, or both.

    1230:    The matrices Au and Bu must be equal in all subcommunicators.

    1232:    The str flag is passed to the MatAXPY() operations to perform the updates.

    1234:    If globalup is true, communication is carried out to reconstruct the updated
    1235:    matrices in the parent communicator. The user must be warned that if global
    1236:    matrices are not in sync with subcommunicator matrices, the errors computed
    1237:    by EPSComputeError() will be wrong even if the computed solution is correct
    1238:    (the synchronization may be done only once at the end).

    1240:    Level: advanced

    1242: .seealso: EPSSetInterval(), EPSKrylovSchurSetPartitions(), EPSKrylovSchurGetSubcommMats()
    1243: @*/
    1244: PetscErrorCode EPSKrylovSchurUpdateSubcommMats(EPS eps,PetscScalar s,PetscScalar a,Mat Au,PetscScalar t,PetscScalar b,Mat Bu,MatStructure str,PetscBool globalup)
    1245: {

    1258:   PetscTryMethod(eps,"EPSKrylovSchurUpdateSubcommMats_C",(EPS,PetscScalar,PetscScalar,Mat,PetscScalar,PetscScalar,Mat,MatStructure,PetscBool),(eps,s,a,Au,t,b,Bu,str,globalup));
    1259:   return(0);
    1260: }

    1262: PetscErrorCode EPSSetFromOptions_KrylovSchur(PetscOptionItems *PetscOptionsObject,EPS eps)
    1263: {
    1264:   PetscErrorCode  ierr;
    1265:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    1266:   PetscBool       flg,lock,b,f1,f2,f3;
    1267:   PetscReal       keep;
    1268:   PetscInt        i,j,k;

    1271:   PetscOptionsHead(PetscOptionsObject,"EPS Krylov-Schur Options");

    1273:     PetscOptionsReal("-eps_krylovschur_restart","Proportion of vectors kept after restart","EPSKrylovSchurSetRestart",0.5,&keep,&flg);
    1274:     if (flg) { EPSKrylovSchurSetRestart(eps,keep); }

    1276:     PetscOptionsBool("-eps_krylovschur_locking","Choose between locking and non-locking variants","EPSKrylovSchurSetLocking",PETSC_TRUE,&lock,&flg);
    1277:     if (flg) { EPSKrylovSchurSetLocking(eps,lock); }

    1279:     i = ctx->npart;
    1280:     PetscOptionsInt("-eps_krylovschur_partitions","Number of partitions of the communicator for spectrum slicing","EPSKrylovSchurSetPartitions",ctx->npart,&i,&flg);
    1281:     if (flg) { EPSKrylovSchurSetPartitions(eps,i); }

    1283:     b = ctx->detect;
    1284:     PetscOptionsBool("-eps_krylovschur_detect_zeros","Check zeros during factorizations at subinterval boundaries","EPSKrylovSchurSetDetectZeros",ctx->detect,&b,&flg);
    1285:     if (flg) { EPSKrylovSchurSetDetectZeros(eps,b); }

    1287:     i = 1;
    1288:     j = k = PETSC_DECIDE;
    1289:     PetscOptionsInt("-eps_krylovschur_nev","Number of eigenvalues to compute in each subsolve (only for spectrum slicing)","EPSKrylovSchurSetDimensions",40,&i,&f1);
    1290:     PetscOptionsInt("-eps_krylovschur_ncv","Number of basis vectors in each subsolve (only for spectrum slicing)","EPSKrylovSchurSetDimensions",80,&j,&f2);
    1291:     PetscOptionsInt("-eps_krylovschur_mpd","Maximum dimension of projected problem in each subsolve (only for spectrum slicing)","EPSKrylovSchurSetDimensions",80,&k,&f3);
    1292:     if (f1 || f2 || f3) { EPSKrylovSchurSetDimensions(eps,i,j,k); }

    1294:   PetscOptionsTail();
    1295:   return(0);
    1296: }

    1298: PetscErrorCode EPSView_KrylovSchur(EPS eps,PetscViewer viewer)
    1299: {
    1300:   PetscErrorCode  ierr;
    1301:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    1302:   PetscBool       isascii,isfilt;

    1305:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);
    1306:   if (isascii) {
    1307:     PetscViewerASCIIPrintf(viewer,"  %d%% of basis vectors kept after restart\n",(int)(100*ctx->keep));
    1308:     PetscViewerASCIIPrintf(viewer,"  using the %slocking variant\n",ctx->lock?"":"non-");
    1309:     if (eps->which==EPS_ALL) {
    1310:       PetscObjectTypeCompare((PetscObject)eps->st,STFILTER,&isfilt);
    1311:       if (isfilt) {
    1312:         PetscViewerASCIIPrintf(viewer,"  using filtering to extract all eigenvalues in an interval\n");
    1313:       } else {
    1314:         PetscViewerASCIIPrintf(viewer,"  doing spectrum slicing with nev=%D, ncv=%D, mpd=%D\n",ctx->nev,ctx->ncv,ctx->mpd);
    1315:         if (ctx->npart>1) {
    1316:           PetscViewerASCIIPrintf(viewer,"  multi-communicator spectrum slicing with %D partitions\n",ctx->npart);
    1317:           if (ctx->detect) { PetscViewerASCIIPrintf(viewer,"  detecting zeros when factorizing at subinterval boundaries\n"); }
    1318:         }
    1319:       }
    1320:     }
    1321:   }
    1322:   return(0);
    1323: }

    1325: PetscErrorCode EPSDestroy_KrylovSchur(EPS eps)
    1326: {

    1330:   PetscFree(eps->data);
    1331:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetRestart_C",NULL);
    1332:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetRestart_C",NULL);
    1333:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetLocking_C",NULL);
    1334:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetLocking_C",NULL);
    1335:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetPartitions_C",NULL);
    1336:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetPartitions_C",NULL);
    1337:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetDetectZeros_C",NULL);
    1338:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetDetectZeros_C",NULL);
    1339:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetDimensions_C",NULL);
    1340:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetDimensions_C",NULL);
    1341:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetSubintervals_C",NULL);
    1342:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubintervals_C",NULL);
    1343:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetInertias_C",NULL);
    1344:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommInfo_C",NULL);
    1345:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommPairs_C",NULL);
    1346:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommMats_C",NULL);
    1347:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurUpdateSubcommMats_C",NULL);
    1348:   return(0);
    1349: }

    1351: PetscErrorCode EPSReset_KrylovSchur(EPS eps)
    1352: {
    1354:   PetscBool      isfilt;

    1357:   PetscObjectTypeCompare((PetscObject)eps->st,STFILTER,&isfilt);
    1358:   if (eps->which==EPS_ALL && !isfilt) {
    1359:     EPSReset_KrylovSchur_Slice(eps);
    1360:   }
    1361:   return(0);
    1362: }

    1364: PetscErrorCode EPSSetDefaultST_KrylovSchur(EPS eps)
    1365: {

    1369:   if (eps->which==EPS_ALL) {
    1370:     if (!((PetscObject)eps->st)->type_name) {
    1371:       STSetType(eps->st,STSINVERT);
    1372:     }
    1373:   }
    1374:   return(0);
    1375: }

    1377: PETSC_EXTERN PetscErrorCode EPSCreate_KrylovSchur(EPS eps)
    1378: {
    1379:   EPS_KRYLOVSCHUR *ctx;
    1380:   PetscErrorCode  ierr;

    1383:   PetscNewLog(eps,&ctx);
    1384:   eps->data   = (void*)ctx;
    1385:   ctx->lock   = PETSC_TRUE;
    1386:   ctx->nev    = 1;
    1387:   ctx->npart  = 1;
    1388:   ctx->detect = PETSC_FALSE;
    1389:   ctx->global = PETSC_TRUE;

    1391:   eps->useds = PETSC_TRUE;

    1393:   /* solve and computevectors determined at setup */
    1394:   eps->ops->setup          = EPSSetUp_KrylovSchur;
    1395:   eps->ops->setfromoptions = EPSSetFromOptions_KrylovSchur;
    1396:   eps->ops->destroy        = EPSDestroy_KrylovSchur;
    1397:   eps->ops->reset          = EPSReset_KrylovSchur;
    1398:   eps->ops->view           = EPSView_KrylovSchur;
    1399:   eps->ops->backtransform  = EPSBackTransform_Default;
    1400:   eps->ops->setdefaultst   = EPSSetDefaultST_KrylovSchur;

    1402:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetRestart_C",EPSKrylovSchurSetRestart_KrylovSchur);
    1403:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetRestart_C",EPSKrylovSchurGetRestart_KrylovSchur);
    1404:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetLocking_C",EPSKrylovSchurSetLocking_KrylovSchur);
    1405:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetLocking_C",EPSKrylovSchurGetLocking_KrylovSchur);
    1406:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetPartitions_C",EPSKrylovSchurSetPartitions_KrylovSchur);
    1407:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetPartitions_C",EPSKrylovSchurGetPartitions_KrylovSchur);
    1408:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetDetectZeros_C",EPSKrylovSchurSetDetectZeros_KrylovSchur);
    1409:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetDetectZeros_C",EPSKrylovSchurGetDetectZeros_KrylovSchur);
    1410:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetDimensions_C",EPSKrylovSchurSetDimensions_KrylovSchur);
    1411:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetDimensions_C",EPSKrylovSchurGetDimensions_KrylovSchur);
    1412:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetSubintervals_C",EPSKrylovSchurSetSubintervals_KrylovSchur);
    1413:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubintervals_C",EPSKrylovSchurGetSubintervals_KrylovSchur);
    1414:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetInertias_C",EPSKrylovSchurGetInertias_KrylovSchur);
    1415:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommInfo_C",EPSKrylovSchurGetSubcommInfo_KrylovSchur);
    1416:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommPairs_C",EPSKrylovSchurGetSubcommPairs_KrylovSchur);
    1417:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommMats_C",EPSKrylovSchurGetSubcommMats_KrylovSchur);
    1418:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurUpdateSubcommMats_C",EPSKrylovSchurUpdateSubcommMats_KrylovSchur);
    1419:   return(0);
    1420: }