Date: 2020-01-13T12:00:13+00:00

Actual source code: krylovschur.c
slepc-3.12.2 2020-01-13
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2019, 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,EPS_KS_TWOSIDED } 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 if (eps->twosided) {
    189:     variant = EPS_KS_TWOSIDED;
    190:   } else {
    191:     switch (eps->extraction) {
    192:       case EPS_RITZ:     variant = EPS_KS_DEFAULT; break;
    193:       case EPS_HARMONIC: variant = EPS_KS_DEFAULT; break;
    194:       default: SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Unsupported extraction type");
    195:     }
    196:   }
    197:   switch (variant) {
    198:     case EPS_KS_DEFAULT:
    199:       eps->ops->solve = EPSSolve_KrylovSchur_Default;
    200:       eps->ops->computevectors = EPSComputeVectors_Schur;
    201:       DSSetType(eps->ds,DSNHEP);
    202:       DSAllocate(eps->ds,eps->ncv+1);
    203:       break;
    204:     case EPS_KS_SYMM:
    205:     case EPS_KS_FILTER:
    206:       eps->ops->solve = EPSSolve_KrylovSchur_Symm;
    207:       eps->ops->computevectors = EPSComputeVectors_Hermitian;
    208:       DSSetType(eps->ds,DSHEP);
    209:       DSSetCompact(eps->ds,PETSC_TRUE);
    210:       DSSetExtraRow(eps->ds,PETSC_TRUE);
    211:       DSAllocate(eps->ds,eps->ncv+1);
    212:       break;
    213:     case EPS_KS_SLICE:
    214:       if (eps->stopping!=EPSStoppingBasic) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Spectrum slicing does not support user-defined stopping test");
    215:       eps->ops->solve = EPSSolve_KrylovSchur_Slice;
    216:       eps->ops->computevectors = EPSComputeVectors_Slice;
    217:       break;
    218:     case EPS_KS_INDEF:
    219:       eps->ops->solve = EPSSolve_KrylovSchur_Indefinite;
    220:       eps->ops->computevectors = EPSComputeVectors_Indefinite;
    221:       DSSetType(eps->ds,DSGHIEP);
    222:       DSSetCompact(eps->ds,PETSC_TRUE);
    223:       DSAllocate(eps->ds,eps->ncv+1);
    224:       /* force reorthogonalization for pseudo-Lanczos */
    225:       BVGetOrthogonalization(eps->V,&otype,NULL,&eta,&obtype);
    226:       BVSetOrthogonalization(eps->V,otype,BV_ORTHOG_REFINE_ALWAYS,eta,obtype);
    227:       break;
    228:     case EPS_KS_TWOSIDED:
    229:       eps->ops->solve = EPSSolve_KrylovSchur_TwoSided;
    230:       eps->ops->computevectors = EPSComputeVectors_Schur;
    231:       DSSetType(eps->ds,DSNHEP);
    232:       DSAllocate(eps->ds,eps->ncv+1);
    233:       DSSetType(eps->dsts,DSNHEP);
    234:       DSAllocate(eps->dsts,eps->ncv+1);
    235:       break;
    236:     default: SETERRQ(PetscObjectComm((PetscObject)eps),1,"Unexpected error");
    237:   }
    238:   return(0);
    239: }

    241: PetscErrorCode EPSSolve_KrylovSchur_Default(EPS eps)
    242: {
    243:   PetscErrorCode  ierr;
    244:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    245:   PetscInt        i,j,*pj,k,l,nv,ld,nconv;
    246:   Mat             U;
    247:   PetscScalar     *S,*Q,*g;
    248:   PetscReal       beta,gamma=1.0;
    249:   PetscBool       breakdown,harmonic;

    252:   DSGetLeadingDimension(eps->ds,&ld);
    253:   harmonic = (eps->extraction==EPS_HARMONIC || eps->extraction==EPS_REFINED_HARMONIC)?PETSC_TRUE:PETSC_FALSE;
    254:   if (harmonic) { PetscMalloc1(ld,&g); }
    255:   if (eps->arbitrary) pj = &j;
    256:   else pj = NULL;

    258:   /* Get the starting Arnoldi vector */
    259:   EPSGetStartVector(eps,0,NULL);
    260:   l = 0;

    262:   /* Restart loop */
    263:   while (eps->reason == EPS_CONVERGED_ITERATING) {
    264:     eps->its++;

    266:     /* Compute an nv-step Arnoldi factorization */
    267:     nv = PetscMin(eps->nconv+eps->mpd,eps->ncv);
    268:     DSGetArray(eps->ds,DS_MAT_A,&S);
    269:     EPSBasicArnoldi(eps,PETSC_FALSE,S,ld,eps->nconv+l,&nv,&beta,&breakdown);
    270:     DSRestoreArray(eps->ds,DS_MAT_A,&S);
    271:     DSSetDimensions(eps->ds,nv,0,eps->nconv,eps->nconv+l);
    272:     if (l==0) {
    273:       DSSetState(eps->ds,DS_STATE_INTERMEDIATE);
    274:     } else {
    275:       DSSetState(eps->ds,DS_STATE_RAW);
    276:     }
    277:     BVSetActiveColumns(eps->V,eps->nconv,nv);

    279:     /* Compute translation of Krylov decomposition if harmonic extraction used */
    280:     if (harmonic) {
    281:       DSTranslateHarmonic(eps->ds,eps->target,beta,PETSC_FALSE,g,&gamma);
    282:     }

    284:     /* Solve projected problem */
    285:     DSSolve(eps->ds,eps->eigr,eps->eigi);
    286:     if (eps->arbitrary) {
    287:       EPSGetArbitraryValues(eps,eps->rr,eps->ri);
    288:       j=1;
    289:     }
    290:     DSSort(eps->ds,eps->eigr,eps->eigi,eps->rr,eps->ri,pj);
    291:     DSSynchronize(eps->ds,eps->eigr,eps->eigi);

    293:     /* Check convergence */
    294:     EPSKrylovConvergence(eps,PETSC_FALSE,eps->nconv,nv-eps->nconv,beta,0.0,gamma,&k);
    295:     (*eps->stopping)(eps,eps->its,eps->max_it,k,eps->nev,&eps->reason,eps->stoppingctx);
    296:     nconv = k;

    298:     /* Update l */
    299:     if (eps->reason != EPS_CONVERGED_ITERATING || breakdown || k==nv) l = 0;
    300:     else {
    301:       l = PetscMax(1,(PetscInt)((nv-k)*ctx->keep));
    302: #if !defined(PETSC_USE_COMPLEX)
    303:       DSGetArray(eps->ds,DS_MAT_A,&S);
    304:       if (S[k+l+(k+l-1)*ld] != 0.0) {
    305:         if (k+l<nv-1) l = l+1;
    306:         else l = l-1;
    307:       }
    308:       DSRestoreArray(eps->ds,DS_MAT_A,&S);
    309: #endif
    310:     }
    311:     if ((!ctx->lock || harmonic) && l>0) { l += k; k = 0; } /* non-locking variant: reset no. of converged pairs */

    313:     if (eps->reason == EPS_CONVERGED_ITERATING) {
    314:       if (breakdown || k==nv) {
    315:         /* Start a new Arnoldi factorization */
    316:         PetscInfo2(eps,"Breakdown in Krylov-Schur method (it=%D norm=%g)\n",eps->its,(double)beta);
    317:         if (k<eps->nev) {
    318:           EPSGetStartVector(eps,k,&breakdown);
    319:           if (breakdown) {
    320:             eps->reason = EPS_DIVERGED_BREAKDOWN;
    321:             PetscInfo(eps,"Unable to generate more start vectors\n");
    322:           }
    323:         }
    324:       } else {
    325:         /* Undo translation of Krylov decomposition */
    326:         if (harmonic) {
    327:           DSSetDimensions(eps->ds,nv,0,k,l);
    328:           DSTranslateHarmonic(eps->ds,0.0,beta,PETSC_TRUE,g,&gamma);
    329:           /* gamma u^ = u - U*g~ */
    330:           BVMultColumn(eps->V,-1.0,1.0,nv,g);
    331:           BVScaleColumn(eps->V,nv,1.0/gamma);
    332:         }
    333:         /* Prepare the Rayleigh quotient for restart */
    334:         DSGetArray(eps->ds,DS_MAT_A,&S);
    335:         DSGetArray(eps->ds,DS_MAT_Q,&Q);
    336:         for (i=k;i<k+l;i++) {
    337:           S[k+l+i*ld] = Q[nv-1+i*ld]*beta*gamma;
    338:         }
    339:         DSRestoreArray(eps->ds,DS_MAT_A,&S);
    340:         DSRestoreArray(eps->ds,DS_MAT_Q,&Q);
    341:       }
    342:     }
    343:     /* Update the corresponding vectors V(:,idx) = V*Q(:,idx) */
    344:     DSGetMat(eps->ds,DS_MAT_Q,&U);
    345:     BVMultInPlace(eps->V,U,eps->nconv,k+l);
    346:     MatDestroy(&U);

    348:     if (eps->reason == EPS_CONVERGED_ITERATING && !breakdown) {
    349:       BVCopyColumn(eps->V,nv,k+l);
    350:     }
    351:     eps->nconv = k;
    352:     EPSMonitor(eps,eps->its,nconv,eps->eigr,eps->eigi,eps->errest,nv);
    353:   }

    355:   if (harmonic) { PetscFree(g); }
    356:   /* truncate Schur decomposition and change the state to raw so that
    357:      DSVectors() computes eigenvectors from scratch */
    358:   DSSetDimensions(eps->ds,eps->nconv,0,0,0);
    359:   DSSetState(eps->ds,DS_STATE_RAW);
    360:   return(0);
    361: }

    363: static PetscErrorCode EPSKrylovSchurSetRestart_KrylovSchur(EPS eps,PetscReal keep)
    364: {
    365:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    368:   if (keep==PETSC_DEFAULT) ctx->keep = 0.5;
    369:   else {
    370:     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);
    371:     ctx->keep = keep;
    372:   }
    373:   return(0);
    374: }

    376: /*@
    377:    EPSKrylovSchurSetRestart - Sets the restart parameter for the Krylov-Schur
    378:    method, in particular the proportion of basis vectors that must be kept
    379:    after restart.

    381:    Logically Collective on eps

    383:    Input Parameters:
    384: +  eps - the eigenproblem solver context
    385: -  keep - the number of vectors to be kept at restart

    387:    Options Database Key:
    388: .  -eps_krylovschur_restart - Sets the restart parameter

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

    393:    Level: advanced

    395: .seealso: EPSKrylovSchurGetRestart()
    396: @*/
    397: PetscErrorCode EPSKrylovSchurSetRestart(EPS eps,PetscReal keep)
    398: {

    404:   PetscTryMethod(eps,"EPSKrylovSchurSetRestart_C",(EPS,PetscReal),(eps,keep));
    405:   return(0);
    406: }

    408: static PetscErrorCode EPSKrylovSchurGetRestart_KrylovSchur(EPS eps,PetscReal *keep)
    409: {
    410:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    413:   *keep = ctx->keep;
    414:   return(0);
    415: }

    417: /*@
    418:    EPSKrylovSchurGetRestart - Gets the restart parameter used in the
    419:    Krylov-Schur method.

    421:    Not Collective

    423:    Input Parameter:
    424: .  eps - the eigenproblem solver context

    426:    Output Parameter:
    427: .  keep - the restart parameter

    429:    Level: advanced

    431: .seealso: EPSKrylovSchurSetRestart()
    432: @*/
    433: PetscErrorCode EPSKrylovSchurGetRestart(EPS eps,PetscReal *keep)
    434: {

    440:   PetscUseMethod(eps,"EPSKrylovSchurGetRestart_C",(EPS,PetscReal*),(eps,keep));
    441:   return(0);
    442: }

    444: static PetscErrorCode EPSKrylovSchurSetLocking_KrylovSchur(EPS eps,PetscBool lock)
    445: {
    446:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    449:   ctx->lock = lock;
    450:   return(0);
    451: }

    453: /*@
    454:    EPSKrylovSchurSetLocking - Choose between locking and non-locking variants of
    455:    the Krylov-Schur method.

    457:    Logically Collective on eps

    459:    Input Parameters:
    460: +  eps  - the eigenproblem solver context
    461: -  lock - true if the locking variant must be selected

    463:    Options Database Key:
    464: .  -eps_krylovschur_locking - Sets the locking flag

    466:    Notes:
    467:    The default is to lock converged eigenpairs when the method restarts.
    468:    This behaviour can be changed so that all directions are kept in the
    469:    working subspace even if already converged to working accuracy (the
    470:    non-locking variant).

    472:    Level: advanced

    474: .seealso: EPSKrylovSchurGetLocking()
    475: @*/
    476: PetscErrorCode EPSKrylovSchurSetLocking(EPS eps,PetscBool lock)
    477: {

    483:   PetscTryMethod(eps,"EPSKrylovSchurSetLocking_C",(EPS,PetscBool),(eps,lock));
    484:   return(0);
    485: }

    487: static PetscErrorCode EPSKrylovSchurGetLocking_KrylovSchur(EPS eps,PetscBool *lock)
    488: {
    489:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    492:   *lock = ctx->lock;
    493:   return(0);
    494: }

    496: /*@
    497:    EPSKrylovSchurGetLocking - Gets the locking flag used in the Krylov-Schur
    498:    method.

    500:    Not Collective

    502:    Input Parameter:
    503: .  eps - the eigenproblem solver context

    505:    Output Parameter:
    506: .  lock - the locking flag

    508:    Level: advanced

    510: .seealso: EPSKrylovSchurSetLocking()
    511: @*/
    512: PetscErrorCode EPSKrylovSchurGetLocking(EPS eps,PetscBool *lock)
    513: {

    519:   PetscUseMethod(eps,"EPSKrylovSchurGetLocking_C",(EPS,PetscBool*),(eps,lock));
    520:   return(0);
    521: }

    523: static PetscErrorCode EPSKrylovSchurSetPartitions_KrylovSchur(EPS eps,PetscInt npart)
    524: {
    525:   PetscErrorCode  ierr;
    526:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    527:   PetscMPIInt     size;

    530:   if (ctx->npart!=npart) {
    531:     if (ctx->commset) { PetscSubcommDestroy(&ctx->subc); }
    532:     EPSDestroy(&ctx->eps);
    533:   }
    534:   if (npart == PETSC_DEFAULT || npart == PETSC_DECIDE) {
    535:     ctx->npart = 1;
    536:   } else {
    537:     MPI_Comm_size(PetscObjectComm((PetscObject)eps),&size);
    538:     if (npart<1 || npart>size) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of npart");
    539:     ctx->npart = npart;
    540:   }
    541:   eps->state = EPS_STATE_INITIAL;
    542:   return(0);
    543: }

    545: /*@
    546:    EPSKrylovSchurSetPartitions - Sets the number of partitions for the
    547:    case of doing spectrum slicing for a computational interval with the
    548:    communicator split in several sub-communicators.

    550:    Logically Collective on eps

    552:    Input Parameters:
    553: +  eps   - the eigenproblem solver context
    554: -  npart - number of partitions

    556:    Options Database Key:
    557: .  -eps_krylovschur_partitions <npart> - Sets the number of partitions

    559:    Notes:
    560:    By default, npart=1 so all processes in the communicator participate in
    561:    the processing of the whole interval. If npart>1 then the interval is
    562:    divided into npart subintervals, each of them being processed by a
    563:    subset of processes.

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

    568:    Level: advanced

    570: .seealso: EPSKrylovSchurSetSubintervals(), EPSSetInterval()
    571: @*/
    572: PetscErrorCode EPSKrylovSchurSetPartitions(EPS eps,PetscInt npart)
    573: {

    579:   PetscTryMethod(eps,"EPSKrylovSchurSetPartitions_C",(EPS,PetscInt),(eps,npart));
    580:   return(0);
    581: }

    583: static PetscErrorCode EPSKrylovSchurGetPartitions_KrylovSchur(EPS eps,PetscInt *npart)
    584: {
    585:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    588:   *npart  = ctx->npart;
    589:   return(0);
    590: }

    592: /*@
    593:    EPSKrylovSchurGetPartitions - Gets the number of partitions of the
    594:    communicator in case of spectrum slicing.

    596:    Not Collective

    598:    Input Parameter:
    599: .  eps - the eigenproblem solver context

    601:    Output Parameter:
    602: .  npart - number of partitions

    604:    Level: advanced

    606: .seealso: EPSKrylovSchurSetPartitions()
    607: @*/
    608: PetscErrorCode EPSKrylovSchurGetPartitions(EPS eps,PetscInt *npart)
    609: {

    615:   PetscUseMethod(eps,"EPSKrylovSchurGetPartitions_C",(EPS,PetscInt*),(eps,npart));
    616:   return(0);
    617: }

    619: static PetscErrorCode EPSKrylovSchurSetDetectZeros_KrylovSchur(EPS eps,PetscBool detect)
    620: {
    621:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    624:   ctx->detect = detect;
    625:   eps->state  = EPS_STATE_INITIAL;
    626:   return(0);
    627: }

    629: /*@
    630:    EPSKrylovSchurSetDetectZeros - Sets a flag to enforce detection of
    631:    zeros during the factorizations throughout the spectrum slicing computation.

    633:    Logically Collective on eps

    635:    Input Parameters:
    636: +  eps    - the eigenproblem solver context
    637: -  detect - check for zeros

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

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

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

    651:    Level: advanced

    653: .seealso: EPSKrylovSchurSetPartitions(), EPSSetInterval()
    654: @*/
    655: PetscErrorCode EPSKrylovSchurSetDetectZeros(EPS eps,PetscBool detect)
    656: {

    662:   PetscTryMethod(eps,"EPSKrylovSchurSetDetectZeros_C",(EPS,PetscBool),(eps,detect));
    663:   return(0);
    664: }

    666: static PetscErrorCode EPSKrylovSchurGetDetectZeros_KrylovSchur(EPS eps,PetscBool *detect)
    667: {
    668:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    671:   *detect = ctx->detect;
    672:   return(0);
    673: }

    675: /*@
    676:    EPSKrylovSchurGetDetectZeros - Gets the flag that enforces zero detection
    677:    in spectrum slicing.

    679:    Not Collective

    681:    Input Parameter:
    682: .  eps - the eigenproblem solver context

    684:    Output Parameter:
    685: .  detect - whether zeros detection is enforced during factorizations

    687:    Level: advanced

    689: .seealso: EPSKrylovSchurSetDetectZeros()
    690: @*/
    691: PetscErrorCode EPSKrylovSchurGetDetectZeros(EPS eps,PetscBool *detect)
    692: {

    698:   PetscUseMethod(eps,"EPSKrylovSchurGetDetectZeros_C",(EPS,PetscBool*),(eps,detect));
    699:   return(0);
    700: }

    702: static PetscErrorCode EPSKrylovSchurSetDimensions_KrylovSchur(EPS eps,PetscInt nev,PetscInt ncv,PetscInt mpd)
    703: {
    704:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    707:   if (nev<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of nev. Must be > 0");
    708:   ctx->nev = nev;
    709:   if (ncv == PETSC_DECIDE || ncv == PETSC_DEFAULT) {
    710:     ctx->ncv = 0;
    711:   } else {
    712:     if (ncv<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ncv. Must be > 0");
    713:     ctx->ncv = ncv;
    714:   }
    715:   if (mpd == PETSC_DECIDE || mpd == PETSC_DEFAULT) {
    716:     ctx->mpd = 0;
    717:   } else {
    718:     if (mpd<1) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of mpd. Must be > 0");
    719:     ctx->mpd = mpd;
    720:   }
    721:   eps->state = EPS_STATE_INITIAL;
    722:   return(0);
    723: }

    725: /*@
    726:    EPSKrylovSchurSetDimensions - Sets the dimensions used for each subsolve
    727:    step in case of doing spectrum slicing for a computational interval.
    728:    The meaning of the parameters is the same as in EPSSetDimensions().

    730:    Logically Collective on eps

    732:    Input Parameters:
    733: +  eps - the eigenproblem solver context
    734: .  nev - number of eigenvalues to compute
    735: .  ncv - the maximum dimension of the subspace to be used by the subsolve
    736: -  mpd - the maximum dimension allowed for the projected problem

    738:    Options Database Key:
    739: +  -eps_krylovschur_nev <nev> - Sets the number of eigenvalues
    740: .  -eps_krylovschur_ncv <ncv> - Sets the dimension of the subspace
    741: -  -eps_krylovschur_mpd <mpd> - Sets the maximum projected dimension

    743:    Level: advanced

    745: .seealso: EPSKrylovSchurGetDimensions(), EPSSetDimensions(), EPSSetInterval()
    746: @*/
    747: PetscErrorCode EPSKrylovSchurSetDimensions(EPS eps,PetscInt nev,PetscInt ncv,PetscInt mpd)
    748: {

    756:   PetscTryMethod(eps,"EPSKrylovSchurSetDimensions_C",(EPS,PetscInt,PetscInt,PetscInt),(eps,nev,ncv,mpd));
    757:   return(0);
    758: }

    760: static PetscErrorCode EPSKrylovSchurGetDimensions_KrylovSchur(EPS eps,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
    761: {
    762:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    765:   if (nev) *nev = ctx->nev;
    766:   if (ncv) *ncv = ctx->ncv;
    767:   if (mpd) *mpd = ctx->mpd;
    768:   return(0);
    769: }

    771: /*@
    772:    EPSKrylovSchurGetDimensions - Gets the dimensions used for each subsolve
    773:    step in case of doing spectrum slicing for a computational interval.

    775:    Not Collective

    777:    Input Parameter:
    778: .  eps - the eigenproblem solver context

    780:    Output Parameters:
    781: +  nev - number of eigenvalues to compute
    782: .  ncv - the maximum dimension of the subspace to be used by the subsolve
    783: -  mpd - the maximum dimension allowed for the projected problem

    785:    Level: advanced

    787: .seealso: EPSKrylovSchurSetDimensions()
    788: @*/
    789: PetscErrorCode EPSKrylovSchurGetDimensions(EPS eps,PetscInt *nev,PetscInt *ncv,PetscInt *mpd)
    790: {

    795:   PetscUseMethod(eps,"EPSKrylovSchurGetDimensions_C",(EPS,PetscInt*,PetscInt*,PetscInt*),(eps,nev,ncv,mpd));
    796:   return(0);
    797: }

    799: static PetscErrorCode EPSKrylovSchurSetSubintervals_KrylovSchur(EPS eps,PetscReal* subint)
    800: {
    801:   PetscErrorCode  ierr;
    802:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    803:   PetscInt        i;

    806:   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()");
    807:   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");
    808:   if (ctx->subintervals) { PetscFree(ctx->subintervals); }
    809:   PetscMalloc1(ctx->npart+1,&ctx->subintervals);
    810:   for (i=0;i<ctx->npart+1;i++) ctx->subintervals[i] = subint[i];
    811:   ctx->subintset = PETSC_TRUE;
    812:   eps->state = EPS_STATE_INITIAL;
    813:   return(0);
    814: }

    816: /*@C
    817:    EPSKrylovSchurSetSubintervals - Sets the points that delimit the
    818:    subintervals to be used in spectrum slicing with several partitions.

    820:    Logically Collective on eps

    822:    Input Parameters:
    823: +  eps    - the eigenproblem solver context
    824: -  subint - array of real values specifying subintervals

    826:    Notes:
    827:    This function must be called after EPSKrylovSchurSetPartitions(). For npart
    828:    partitions, the argument subint must contain npart+1 real values sorted in
    829:    ascending order: subint_0, subint_1, ..., subint_npart, where the first
    830:    and last values must coincide with the interval endpoints set with
    831:    EPSSetInterval().

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

    836:    Level: advanced

    838: .seealso: EPSKrylovSchurSetPartitions(), EPSKrylovSchurGetSubintervals(), EPSSetInterval()
    839: @*/
    840: PetscErrorCode EPSKrylovSchurSetSubintervals(EPS eps,PetscReal *subint)
    841: {

    846:   PetscTryMethod(eps,"EPSKrylovSchurSetSubintervals_C",(EPS,PetscReal*),(eps,subint));
    847:   return(0);
    848: }

    850: static PetscErrorCode EPSKrylovSchurGetSubintervals_KrylovSchur(EPS eps,PetscReal **subint)
    851: {
    852:   PetscErrorCode  ierr;
    853:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    854:   PetscInt        i;

    857:   if (!ctx->subintset) {
    858:     if (!eps->state) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Must call EPSSetUp() first");
    859:     if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    860:   }
    861:   PetscMalloc1(ctx->npart+1,subint);
    862:   for (i=0;i<=ctx->npart;i++) (*subint)[i] = ctx->subintervals[i];
    863:   return(0);
    864: }

    866: /*@C
    867:    EPSKrylovSchurGetSubintervals - Returns the points that delimit the
    868:    subintervals used in spectrum slicing with several partitions.

    870:    Logically Collective on eps

    872:    Input Parameter:
    873: .  eps    - the eigenproblem solver context

    875:    Output Parameter:
    876: .  subint - array of real values specifying subintervals

    878:    Notes:
    879:    If the user passed values with EPSKrylovSchurSetSubintervals(), then the
    880:    same values are returned. Otherwise, the values computed internally are
    881:    obtained.

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

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

    888:    Fortran Notes:
    889:    The calling sequence from Fortran is
    890: .vb
    891:    EPSKrylovSchurGetSubintervals(eps,subint,ierr)
    892:    double precision subint(npart+1) output
    893: .ve

    895:    Level: advanced

    897: .seealso: EPSKrylovSchurSetSubintervals(), EPSKrylovSchurGetPartitions(), EPSSetInterval()
    898: @*/
    899: PetscErrorCode EPSKrylovSchurGetSubintervals(EPS eps,PetscReal **subint)
    900: {

    906:   PetscUseMethod(eps,"EPSKrylovSchurGetSubintervals_C",(EPS,PetscReal**),(eps,subint));
    907:   return(0);
    908: }

    910: static PetscErrorCode EPSKrylovSchurGetInertias_KrylovSchur(EPS eps,PetscInt *n,PetscReal **shifts,PetscInt **inertias)
    911: {
    912:   PetscErrorCode  ierr;
    913:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    914:   PetscInt        i,numsh;
    915:   EPS_SR          sr = ctx->sr;

    918:   if (!eps->state) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Must call EPSSetUp() first");
    919:   if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    920:   switch (eps->state) {
    921:   case EPS_STATE_INITIAL:
    922:     break;
    923:   case EPS_STATE_SETUP:
    924:     numsh = ctx->npart+1;
    925:     if (n) *n = numsh;
    926:     if (shifts) {
    927:       PetscMalloc1(numsh,shifts);
    928:       (*shifts)[0] = eps->inta;
    929:       if (ctx->npart==1) (*shifts)[1] = eps->intb;
    930:       else for (i=1;i<numsh;i++) (*shifts)[i] = ctx->subintervals[i];
    931:     }
    932:     if (inertias) {
    933:       PetscMalloc1(numsh,inertias);
    934:       (*inertias)[0] = (sr->dir==1)?sr->inertia0:sr->inertia1;
    935:       if (ctx->npart==1) (*inertias)[1] = (sr->dir==1)?sr->inertia1:sr->inertia0;
    936:       else for (i=1;i<numsh;i++) (*inertias)[i] = (*inertias)[i-1]+ctx->nconv_loc[i-1];
    937:     }
    938:     break;
    939:   case EPS_STATE_SOLVED:
    940:   case EPS_STATE_EIGENVECTORS:
    941:     numsh = ctx->nshifts;
    942:     if (n) *n = numsh;
    943:     if (shifts) {
    944:       PetscMalloc1(numsh,shifts);
    945:       for (i=0;i<numsh;i++) (*shifts)[i] = ctx->shifts[i];
    946:     }
    947:     if (inertias) {
    948:       PetscMalloc1(numsh,inertias);
    949:       for (i=0;i<numsh;i++) (*inertias)[i] = ctx->inertias[i];
    950:     }
    951:     break;
    952:   }
    953:   return(0);
    954: }

    956: /*@C
    957:    EPSKrylovSchurGetInertias - Gets the values of the shifts and their
    958:    corresponding inertias in case of doing spectrum slicing for a
    959:    computational interval.

    961:    Not Collective

    963:    Input Parameter:
    964: .  eps - the eigenproblem solver context

    966:    Output Parameters:
    967: +  n        - number of shifts, including the endpoints of the interval
    968: .  shifts   - the values of the shifts used internally in the solver
    969: -  inertias - the values of the inertia in each shift

    971:    Notes:
    972:    If called after EPSSolve(), all shifts used internally by the solver are
    973:    returned (including both endpoints and any intermediate ones). If called
    974:    before EPSSolve() and after EPSSetUp() then only the information of the
    975:    endpoints of subintervals is available.

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

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

    982:    Fortran Notes:
    983:    The calling sequence from Fortran is
    984: .vb
    985:    EPSKrylovSchurGetInertias(eps,n,shifts,inertias,ierr)
    986:    integer n
    987:    double precision shifts(*)
    988:    integer inertias(*)
    989: .ve
    990:    The arrays should be at least of length n. The value of n can be determined
    991:    by an initial call
    992: .vb
    993:    EPSKrylovSchurGetInertias(eps,n,PETSC_NULL_REAL,PETSC_NULL_INTEGER,ierr)
    994: .ve

    996:    Level: advanced

    998: .seealso: EPSSetInterval(), EPSKrylovSchurSetSubintervals()
    999: @*/
    1000: PetscErrorCode EPSKrylovSchurGetInertias(EPS eps,PetscInt *n,PetscReal **shifts,PetscInt **inertias)
    1001: {

    1007:   PetscUseMethod(eps,"EPSKrylovSchurGetInertias_C",(EPS,PetscInt*,PetscReal**,PetscInt**),(eps,n,shifts,inertias));
    1008:   return(0);
    1009: }

    1011: static PetscErrorCode EPSKrylovSchurGetSubcommInfo_KrylovSchur(EPS eps,PetscInt *k,PetscInt *n,Vec *v)
    1012: {
    1013:   PetscErrorCode  ierr;
    1014:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    1015:   EPS_SR          sr = ((EPS_KRYLOVSCHUR*)ctx->eps->data)->sr;

    1018:   if (!eps->state) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Must call EPSSetUp() first");
    1019:   if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    1020:   if (k) *k = (ctx->npart==1)? 0: ctx->subc->color;
    1021:   if (n) *n = sr->numEigs;
    1022:   if (v) {
    1023:     BVCreateVec(sr->V,v);
    1024:   }
    1025:   return(0);
    1026: }

    1028: /*@C
    1029:    EPSKrylovSchurGetSubcommInfo - Gets information related to the case of
    1030:    doing spectrum slicing for a computational interval with multiple
    1031:    communicators.

    1033:    Collective on the subcommunicator (if v is given)

    1035:    Input Parameter:
    1036: .  eps - the eigenproblem solver context

    1038:    Output Parameters:
    1039: +  k - index of the subinterval for the calling process
    1040: .  n - number of eigenvalues found in the k-th subinterval
    1041: -  v - a vector owned by processes in the subcommunicator with dimensions
    1042:        compatible for locally computed eigenvectors (or NULL)

    1044:    Notes:
    1045:    This function is only available for spectrum slicing runs.

    1047:    The returned Vec should be destroyed by the user.

    1049:    Level: advanced

    1051: .seealso: EPSSetInterval(), EPSKrylovSchurSetPartitions(), EPSKrylovSchurGetSubcommPairs()
    1052: @*/
    1053: PetscErrorCode EPSKrylovSchurGetSubcommInfo(EPS eps,PetscInt *k,PetscInt *n,Vec *v)
    1054: {

    1059:   PetscUseMethod(eps,"EPSKrylovSchurGetSubcommInfo_C",(EPS,PetscInt*,PetscInt*,Vec*),(eps,k,n,v));
    1060:   return(0);
    1061: }

    1063: static PetscErrorCode EPSKrylovSchurGetSubcommPairs_KrylovSchur(EPS eps,PetscInt i,PetscScalar *eig,Vec v)
    1064: {
    1065:   PetscErrorCode  ierr;
    1066:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    1067:   EPS_SR          sr = ((EPS_KRYLOVSCHUR*)ctx->eps->data)->sr;

    1070:   EPSCheckSolved(eps,1);
    1071:   if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    1072:   if (i<0 || i>=sr->numEigs) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Argument 2 out of range");
    1073:   if (eig) *eig = sr->eigr[sr->perm[i]];
    1074:   if (v) { BVCopyVec(sr->V,sr->perm[i],v); }
    1075:   return(0);
    1076: }

    1078: /*@
    1079:    EPSKrylovSchurGetSubcommPairs - Gets the i-th eigenpair stored
    1080:    internally in the subcommunicator to which the calling process belongs.

    1082:    Collective on the subcommunicator (if v is given)

    1084:    Input Parameter:
    1085: +  eps - the eigenproblem solver context
    1086: -  i   - index of the solution

    1088:    Output Parameters:
    1089: +  eig - the eigenvalue
    1090: -  v   - the eigenvector

    1092:    Notes:
    1093:    It is allowed to pass NULL for v if the eigenvector is not required.
    1094:    Otherwise, the caller must provide a valid Vec objects, i.e.,
    1095:    it must be created by the calling program with EPSKrylovSchurGetSubcommInfo().

    1097:    The index i should be a value between 0 and n-1, where n is the number of
    1098:    vectors in the local subinterval, see EPSKrylovSchurGetSubcommInfo().

    1100:    Level: advanced

    1102: .seealso: EPSSetInterval(), EPSKrylovSchurSetPartitions(), EPSKrylovSchurGetSubcommInfo(), EPSKrylovSchurGetSubcommMats()
    1103: @*/
    1104: PetscErrorCode EPSKrylovSchurGetSubcommPairs(EPS eps,PetscInt i,PetscScalar *eig,Vec v)
    1105: {

    1111:   PetscUseMethod(eps,"EPSKrylovSchurGetSubcommPairs_C",(EPS,PetscInt,PetscScalar*,Vec),(eps,i,eig,v));
    1112:   return(0);
    1113: }

    1115: static PetscErrorCode EPSKrylovSchurGetSubcommMats_KrylovSchur(EPS eps,Mat *A,Mat *B)
    1116: {
    1117:   PetscErrorCode  ierr;
    1118:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;

    1121:   if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    1122:   if (!eps->state) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Must call EPSSetUp() first");
    1123:   EPSGetOperators(ctx->eps,A,B);
    1124:   return(0);
    1125: }

    1127: /*@C
    1128:    EPSKrylovSchurGetSubcommMats - Gets the eigenproblem matrices stored
    1129:    internally in the subcommunicator to which the calling process belongs.

    1131:    Collective on the subcommunicator

    1133:    Input Parameter:
    1134: .  eps - the eigenproblem solver context

    1136:    Output Parameters:
    1137: +  A  - the matrix associated with the eigensystem
    1138: -  B  - the second matrix in the case of generalized eigenproblems

    1140:    Notes:
    1141:    This is the analog of EPSGetOperators(), but returns the matrices distributed
    1142:    differently (in the subcommunicator rather than in the parent communicator).

    1144:    These matrices should not be modified by the user.

    1146:    Level: advanced

    1148: .seealso: EPSSetInterval(), EPSKrylovSchurSetPartitions(), EPSKrylovSchurGetSubcommInfo()
    1149: @*/
    1150: PetscErrorCode EPSKrylovSchurGetSubcommMats(EPS eps,Mat *A,Mat *B)
    1151: {

    1156:   PetscTryMethod(eps,"EPSKrylovSchurGetSubcommMats_C",(EPS,Mat*,Mat*),(eps,A,B));
    1157:   return(0);
    1158: }

    1160: static PetscErrorCode EPSKrylovSchurUpdateSubcommMats_KrylovSchur(EPS eps,PetscScalar a,PetscScalar ap,Mat Au,PetscScalar b,PetscScalar bp, Mat Bu,MatStructure str,PetscBool globalup)
    1161: {
    1162:   PetscErrorCode  ierr;
    1163:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data,*subctx;
    1164:   Mat             A,B=NULL,Ag,Bg=NULL;
    1165:   PetscBool       reuse=PETSC_TRUE;

    1168:   if (!ctx->sr) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Only available in interval computations, see EPSSetInterval()");
    1169:   if (!eps->state) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"Must call EPSSetUp() first");
    1170:   EPSGetOperators(eps,&Ag,&Bg);
    1171:   EPSGetOperators(ctx->eps,&A,&B);

    1173:   MatScale(A,a);
    1174:   if (Au) {
    1175:     MatAXPY(A,ap,Au,str);
    1176:   }
    1177:   if (B) MatScale(B,b);
    1178:   if (Bu) {
    1179:     MatAXPY(B,bp,Bu,str);
    1180:   }
    1181:   EPSSetOperators(ctx->eps,A,B);

    1183:   /* Update stored matrix state */
    1184:   subctx = (EPS_KRYLOVSCHUR*)ctx->eps->data;
    1185:   PetscObjectStateGet((PetscObject)A,&subctx->Astate);
    1186:   if (B) { PetscObjectStateGet((PetscObject)B,&subctx->Bstate); }

    1188:   /* Update matrices in the parent communicator if requested by user */
    1189:   if (globalup) {
    1190:     if (ctx->npart>1) {
    1191:       if (!ctx->isrow) {
    1192:         MatGetOwnershipIS(Ag,&ctx->isrow,&ctx->iscol);
    1193:         reuse = PETSC_FALSE;
    1194:       }
    1195:       if (str==DIFFERENT_NONZERO_PATTERN) reuse = PETSC_FALSE;
    1196:       if (ctx->submata && !reuse) {
    1197:         MatDestroyMatrices(1,&ctx->submata);
    1198:       }
    1199:       MatCreateSubMatrices(A,1,&ctx->isrow,&ctx->iscol,(reuse)?MAT_REUSE_MATRIX:MAT_INITIAL_MATRIX,&ctx->submata);
    1200:       MatCreateMPIMatConcatenateSeqMat(((PetscObject)Ag)->comm,ctx->submata[0],PETSC_DECIDE,MAT_REUSE_MATRIX,&Ag);
    1201:       if (B) {
    1202:         if (ctx->submatb && !reuse) {
    1203:           MatDestroyMatrices(1,&ctx->submatb);
    1204:         }
    1205:         MatCreateSubMatrices(B,1,&ctx->isrow,&ctx->iscol,(reuse)?MAT_REUSE_MATRIX:MAT_INITIAL_MATRIX,&ctx->submatb);
    1206:         MatCreateMPIMatConcatenateSeqMat(((PetscObject)Bg)->comm,ctx->submatb[0],PETSC_DECIDE,MAT_REUSE_MATRIX,&Bg);
    1207:       }
    1208:     }
    1209:     PetscObjectStateGet((PetscObject)Ag,&ctx->Astate);
    1210:     if (Bg) { PetscObjectStateGet((PetscObject)Bg,&ctx->Bstate); }
    1211:   }
    1212:   EPSSetOperators(eps,Ag,Bg);
    1213:   return(0);
    1214: }

    1216: /*@
    1217:    EPSKrylovSchurUpdateSubcommMats - Update the eigenproblem matrices stored
    1218:    internally in the subcommunicator to which the calling process belongs.

    1220:    Collective on eps

    1222:    Input Parameters:
    1223: +  eps - the eigenproblem solver context
    1224: .  s   - scalar that multiplies the existing A matrix
    1225: .  a   - scalar used in the axpy operation on A
    1226: .  Au  - matrix used in the axpy operation on A
    1227: .  t   - scalar that multiplies the existing B matrix
    1228: .  b   - scalar used in the axpy operation on B
    1229: .  Bu  - matrix used in the axpy operation on B
    1230: .  str - structure flag
    1231: -  globalup - flag indicating if global matrices must be updated

    1233:    Notes:
    1234:    This function modifies the eigenproblem matrices at the subcommunicator level,
    1235:    and optionally updates the global matrices in the parent communicator. The updates
    1236:    are expressed as A <-- s*A + a*Au,  B <-- t*B + b*Bu.

    1238:    It is possible to update one of the matrices, or both.

    1240:    The matrices Au and Bu must be equal in all subcommunicators.

    1242:    The str flag is passed to the MatAXPY() operations to perform the updates.

    1244:    If globalup is true, communication is carried out to reconstruct the updated
    1245:    matrices in the parent communicator. The user must be warned that if global
    1246:    matrices are not in sync with subcommunicator matrices, the errors computed
    1247:    by EPSComputeError() will be wrong even if the computed solution is correct
    1248:    (the synchronization may be done only once at the end).

    1250:    Level: advanced

    1252: .seealso: EPSSetInterval(), EPSKrylovSchurSetPartitions(), EPSKrylovSchurGetSubcommMats()
    1253: @*/
    1254: PetscErrorCode EPSKrylovSchurUpdateSubcommMats(EPS eps,PetscScalar s,PetscScalar a,Mat Au,PetscScalar t,PetscScalar b,Mat Bu,MatStructure str,PetscBool globalup)
    1255: {

    1268:   PetscTryMethod(eps,"EPSKrylovSchurUpdateSubcommMats_C",(EPS,PetscScalar,PetscScalar,Mat,PetscScalar,PetscScalar,Mat,MatStructure,PetscBool),(eps,s,a,Au,t,b,Bu,str,globalup));
    1269:   return(0);
    1270: }

    1272: PetscErrorCode EPSSetFromOptions_KrylovSchur(PetscOptionItems *PetscOptionsObject,EPS eps)
    1273: {
    1274:   PetscErrorCode  ierr;
    1275:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    1276:   PetscBool       flg,lock,b,f1,f2,f3;
    1277:   PetscReal       keep;
    1278:   PetscInt        i,j,k;

    1281:   PetscOptionsHead(PetscOptionsObject,"EPS Krylov-Schur Options");

    1283:     PetscOptionsReal("-eps_krylovschur_restart","Proportion of vectors kept after restart","EPSKrylovSchurSetRestart",0.5,&keep,&flg);
    1284:     if (flg) { EPSKrylovSchurSetRestart(eps,keep); }

    1286:     PetscOptionsBool("-eps_krylovschur_locking","Choose between locking and non-locking variants","EPSKrylovSchurSetLocking",PETSC_TRUE,&lock,&flg);
    1287:     if (flg) { EPSKrylovSchurSetLocking(eps,lock); }

    1289:     i = ctx->npart;
    1290:     PetscOptionsInt("-eps_krylovschur_partitions","Number of partitions of the communicator for spectrum slicing","EPSKrylovSchurSetPartitions",ctx->npart,&i,&flg);
    1291:     if (flg) { EPSKrylovSchurSetPartitions(eps,i); }

    1293:     b = ctx->detect;
    1294:     PetscOptionsBool("-eps_krylovschur_detect_zeros","Check zeros during factorizations at subinterval boundaries","EPSKrylovSchurSetDetectZeros",ctx->detect,&b,&flg);
    1295:     if (flg) { EPSKrylovSchurSetDetectZeros(eps,b); }

    1297:     i = 1;
    1298:     j = k = PETSC_DECIDE;
    1299:     PetscOptionsInt("-eps_krylovschur_nev","Number of eigenvalues to compute in each subsolve (only for spectrum slicing)","EPSKrylovSchurSetDimensions",40,&i,&f1);
    1300:     PetscOptionsInt("-eps_krylovschur_ncv","Number of basis vectors in each subsolve (only for spectrum slicing)","EPSKrylovSchurSetDimensions",80,&j,&f2);
    1301:     PetscOptionsInt("-eps_krylovschur_mpd","Maximum dimension of projected problem in each subsolve (only for spectrum slicing)","EPSKrylovSchurSetDimensions",80,&k,&f3);
    1302:     if (f1 || f2 || f3) { EPSKrylovSchurSetDimensions(eps,i,j,k); }

    1304:   PetscOptionsTail();
    1305:   return(0);
    1306: }

    1308: PetscErrorCode EPSView_KrylovSchur(EPS eps,PetscViewer viewer)
    1309: {
    1310:   PetscErrorCode  ierr;
    1311:   EPS_KRYLOVSCHUR *ctx = (EPS_KRYLOVSCHUR*)eps->data;
    1312:   PetscBool       isascii,isfilt;

    1315:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);
    1316:   if (isascii) {
    1317:     PetscViewerASCIIPrintf(viewer,"  %d%% of basis vectors kept after restart\n",(int)(100*ctx->keep));
    1318:     PetscViewerASCIIPrintf(viewer,"  using the %slocking variant\n",ctx->lock?"":"non-");
    1319:     if (eps->which==EPS_ALL) {
    1320:       PetscObjectTypeCompare((PetscObject)eps->st,STFILTER,&isfilt);
    1321:       if (isfilt) {
    1322:         PetscViewerASCIIPrintf(viewer,"  using filtering to extract all eigenvalues in an interval\n");
    1323:       } else {
    1324:         PetscViewerASCIIPrintf(viewer,"  doing spectrum slicing with nev=%D, ncv=%D, mpd=%D\n",ctx->nev,ctx->ncv,ctx->mpd);
    1325:         if (ctx->npart>1) {
    1326:           PetscViewerASCIIPrintf(viewer,"  multi-communicator spectrum slicing with %D partitions\n",ctx->npart);
    1327:           if (ctx->detect) { PetscViewerASCIIPrintf(viewer,"  detecting zeros when factorizing at subinterval boundaries\n"); }
    1328:         }
    1329:       }
    1330:     }
    1331:   }
    1332:   return(0);
    1333: }

    1335: PetscErrorCode EPSDestroy_KrylovSchur(EPS eps)
    1336: {

    1340:   PetscFree(eps->data);
    1341:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetRestart_C",NULL);
    1342:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetRestart_C",NULL);
    1343:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetLocking_C",NULL);
    1344:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetLocking_C",NULL);
    1345:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetPartitions_C",NULL);
    1346:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetPartitions_C",NULL);
    1347:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetDetectZeros_C",NULL);
    1348:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetDetectZeros_C",NULL);
    1349:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetDimensions_C",NULL);
    1350:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetDimensions_C",NULL);
    1351:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetSubintervals_C",NULL);
    1352:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubintervals_C",NULL);
    1353:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetInertias_C",NULL);
    1354:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommInfo_C",NULL);
    1355:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommPairs_C",NULL);
    1356:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommMats_C",NULL);
    1357:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurUpdateSubcommMats_C",NULL);
    1358:   return(0);
    1359: }

    1361: PetscErrorCode EPSReset_KrylovSchur(EPS eps)
    1362: {
    1364:   PetscBool      isfilt;

    1367:   PetscObjectTypeCompare((PetscObject)eps->st,STFILTER,&isfilt);
    1368:   if (eps->which==EPS_ALL && !isfilt) {
    1369:     EPSReset_KrylovSchur_Slice(eps);
    1370:   }
    1371:   return(0);
    1372: }

    1374: PetscErrorCode EPSSetDefaultST_KrylovSchur(EPS eps)
    1375: {

    1379:   if (eps->which==EPS_ALL) {
    1380:     if (!((PetscObject)eps->st)->type_name) {
    1381:       STSetType(eps->st,STSINVERT);
    1382:     }
    1383:   }
    1384:   return(0);
    1385: }

    1387: SLEPC_EXTERN PetscErrorCode EPSCreate_KrylovSchur(EPS eps)
    1388: {
    1389:   EPS_KRYLOVSCHUR *ctx;
    1390:   PetscErrorCode  ierr;

    1393:   PetscNewLog(eps,&ctx);
    1394:   eps->data   = (void*)ctx;
    1395:   ctx->lock   = PETSC_TRUE;
    1396:   ctx->nev    = 1;
    1397:   ctx->npart  = 1;
    1398:   ctx->detect = PETSC_FALSE;
    1399:   ctx->global = PETSC_TRUE;

    1401:   eps->useds = PETSC_TRUE;
    1402:   eps->hasts = PETSC_TRUE;

    1404:   /* solve and computevectors determined at setup */
    1405:   eps->ops->setup          = EPSSetUp_KrylovSchur;
    1406:   eps->ops->setfromoptions = EPSSetFromOptions_KrylovSchur;
    1407:   eps->ops->destroy        = EPSDestroy_KrylovSchur;
    1408:   eps->ops->reset          = EPSReset_KrylovSchur;
    1409:   eps->ops->view           = EPSView_KrylovSchur;
    1410:   eps->ops->backtransform  = EPSBackTransform_Default;
    1411:   eps->ops->setdefaultst   = EPSSetDefaultST_KrylovSchur;

    1413:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetRestart_C",EPSKrylovSchurSetRestart_KrylovSchur);
    1414:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetRestart_C",EPSKrylovSchurGetRestart_KrylovSchur);
    1415:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetLocking_C",EPSKrylovSchurSetLocking_KrylovSchur);
    1416:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetLocking_C",EPSKrylovSchurGetLocking_KrylovSchur);
    1417:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetPartitions_C",EPSKrylovSchurSetPartitions_KrylovSchur);
    1418:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetPartitions_C",EPSKrylovSchurGetPartitions_KrylovSchur);
    1419:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetDetectZeros_C",EPSKrylovSchurSetDetectZeros_KrylovSchur);
    1420:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetDetectZeros_C",EPSKrylovSchurGetDetectZeros_KrylovSchur);
    1421:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetDimensions_C",EPSKrylovSchurSetDimensions_KrylovSchur);
    1422:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetDimensions_C",EPSKrylovSchurGetDimensions_KrylovSchur);
    1423:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurSetSubintervals_C",EPSKrylovSchurSetSubintervals_KrylovSchur);
    1424:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubintervals_C",EPSKrylovSchurGetSubintervals_KrylovSchur);
    1425:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetInertias_C",EPSKrylovSchurGetInertias_KrylovSchur);
    1426:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommInfo_C",EPSKrylovSchurGetSubcommInfo_KrylovSchur);
    1427:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommPairs_C",EPSKrylovSchurGetSubcommPairs_KrylovSchur);
    1428:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurGetSubcommMats_C",EPSKrylovSchurGetSubcommMats_KrylovSchur);
    1429:   PetscObjectComposeFunction((PetscObject)eps,"EPSKrylovSchurUpdateSubcommMats_C",EPSKrylovSchurUpdateSubcommMats_KrylovSchur);
    1430:   return(0);
    1431: }