Date: 2015-09-03T15:04:31+00:00

Actual source code: epssetup.c
slepc-3.6.1 2015-09-03
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      1: /*
      2:       EPS routines related to problem setup.

      4:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      5:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      6:    Copyright (c) 2002-2015, Universitat Politecnica de Valencia, Spain

      8:    This file is part of SLEPc.

     10:    SLEPc is free software: you can redistribute it and/or modify it under  the
     11:    terms of version 3 of the GNU Lesser General Public License as published by
     12:    the Free Software Foundation.

     14:    SLEPc  is  distributed in the hope that it will be useful, but WITHOUT  ANY
     15:    WARRANTY;  without even the implied warranty of MERCHANTABILITY or  FITNESS
     16:    FOR  A  PARTICULAR PURPOSE. See the GNU Lesser General Public  License  for
     17:    more details.

     19:    You  should have received a copy of the GNU Lesser General  Public  License
     20:    along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
     21:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     22: */

     24: #include <slepc/private/epsimpl.h>       /*I "slepceps.h" I*/

     28: /*@
     29:    EPSSetUp - Sets up all the internal data structures necessary for the
     30:    execution of the eigensolver. Then calls STSetUp() for any set-up
     31:    operations associated to the ST object.

     33:    Collective on EPS

     35:    Input Parameter:
     36: .  eps   - eigenproblem solver context

     38:    Notes:
     39:    This function need not be called explicitly in most cases, since EPSSolve()
     40:    calls it. It can be useful when one wants to measure the set-up time
     41:    separately from the solve time.

     43:    Level: developer

     45: .seealso: EPSCreate(), EPSSolve(), EPSDestroy(), STSetUp(), EPSSetInitialSpace()
     46: @*/
     47: PetscErrorCode EPSSetUp(EPS eps)
     48: {
     50:   Mat            A,B;
     51:   SlepcSC        sc;
     52:   PetscInt       k,nmat;
     53:   PetscBool      flg,istrivial;
     54: #if defined(PETSC_USE_COMPLEX)
     55:   PetscScalar    sigma;
     56: #endif

     60:   if (eps->state) return(0);
     61:   PetscLogEventBegin(EPS_SetUp,eps,0,0,0);

     63:   /* reset the convergence flag from the previous solves */
     64:   eps->reason = EPS_CONVERGED_ITERATING;

     66:   /* Set default solver type (EPSSetFromOptions was not called) */
     67:   if (!((PetscObject)eps)->type_name) {
     68:     EPSSetType(eps,EPSKRYLOVSCHUR);
     69:   }
     70:   if (!eps->st) { EPSGetST(eps,&eps->st); }
     71:   if (!((PetscObject)eps->st)->type_name) {
     72:     PetscObjectTypeCompareAny((PetscObject)eps,&flg,EPSGD,EPSJD,EPSRQCG,EPSBLOPEX,EPSPRIMME,"");
     73:     STSetType(eps->st,flg?STPRECOND:STSHIFT);
     74:   }
     75:   STSetTransform(eps->st,PETSC_TRUE);
     76:   if (!eps->ds) { EPSGetDS(eps,&eps->ds); }
     77:   DSReset(eps->ds);
     78:   if (!eps->rg) { EPSGetRG(eps,&eps->rg); }
     79:   if (!((PetscObject)eps->rg)->type_name) {
     80:     RGSetType(eps->rg,RGINTERVAL);
     81:   }
     82:   if (!((PetscObject)eps->rand)->type_name) {
     83:     PetscRandomSetFromOptions(eps->rand);
     84:   }

     86:   /* Set problem dimensions */
     87:   STGetNumMatrices(eps->st,&nmat);
     88:   if (!nmat) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONGSTATE,"EPSSetOperators must be called first");
     89:   STMatGetSize(eps->st,&eps->n,NULL);
     90:   STMatGetLocalSize(eps->st,&eps->nloc,NULL);

     92:   /* Set default problem type */
     93:   if (!eps->problem_type) {
     94:     if (nmat==1) {
     95:       EPSSetProblemType(eps,EPS_NHEP);
     96:     } else {
     97:       EPSSetProblemType(eps,EPS_GNHEP);
     98:     }
     99:   } else if (nmat==1 && eps->isgeneralized) {
    100:     PetscInfo(eps,"Eigenproblem set as generalized but no matrix B was provided; reverting to a standard eigenproblem\n");
    101:     eps->isgeneralized = PETSC_FALSE;
    102:     eps->problem_type = eps->ishermitian? EPS_HEP: EPS_NHEP;
    103:   } else if (nmat>1 && !eps->isgeneralized) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_INCOMP,"Inconsistent EPS state");

    105:   if (eps->nev > eps->n) eps->nev = eps->n;
    106:   if (eps->ncv > eps->n) eps->ncv = eps->n;

    108:   /* initialization of matrix norms */
    109:   if (eps->conv==EPS_CONV_NORM) {
    110:     if (!eps->nrma) {
    111:       STGetOperators(eps->st,0,&A);
    112:       MatNorm(A,NORM_INFINITY,&eps->nrma);
    113:     }
    114:     if (nmat>1 && !eps->nrmb) {
    115:       STGetOperators(eps->st,1,&B);
    116:       MatNorm(B,NORM_INFINITY,&eps->nrmb);
    117:     }
    118:   }

    120:   /* call specific solver setup */
    121:   (*eps->ops->setup)(eps);

    123:   /* check extraction */
    124:   PetscObjectTypeCompareAny((PetscObject)eps->st,&flg,STPRECOND,STSHIFT,"");
    125:   if (!flg && eps->extraction && eps->extraction!=EPS_RITZ) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Cannot use a spectral transformation combined with harmonic extraction");

    127:   /* set tolerance if not yet set */
    128:   if (eps->tol==PETSC_DEFAULT) eps->tol = SLEPC_DEFAULT_TOL;

    130:   /* fill sorting criterion context */
    131:   switch (eps->which) {
    132:     case EPS_LARGEST_MAGNITUDE:
    133:       eps->sc->comparison    = SlepcCompareLargestMagnitude;
    134:       eps->sc->comparisonctx = NULL;
    135:       break;
    136:     case EPS_SMALLEST_MAGNITUDE:
    137:       eps->sc->comparison    = SlepcCompareSmallestMagnitude;
    138:       eps->sc->comparisonctx = NULL;
    139:       break;
    140:     case EPS_LARGEST_REAL:
    141:       eps->sc->comparison    = SlepcCompareLargestReal;
    142:       eps->sc->comparisonctx = NULL;
    143:       break;
    144:     case EPS_SMALLEST_REAL:
    145:       eps->sc->comparison    = SlepcCompareSmallestReal;
    146:       eps->sc->comparisonctx = NULL;
    147:       break;
    148:     case EPS_LARGEST_IMAGINARY:
    149:       eps->sc->comparison    = SlepcCompareLargestImaginary;
    150:       eps->sc->comparisonctx = NULL;
    151:       break;
    152:     case EPS_SMALLEST_IMAGINARY:
    153:       eps->sc->comparison    = SlepcCompareSmallestImaginary;
    154:       eps->sc->comparisonctx = NULL;
    155:       break;
    156:     case EPS_TARGET_MAGNITUDE:
    157:       eps->sc->comparison    = SlepcCompareTargetMagnitude;
    158:       eps->sc->comparisonctx = &eps->target;
    159:       break;
    160:     case EPS_TARGET_REAL:
    161:       eps->sc->comparison    = SlepcCompareTargetReal;
    162:       eps->sc->comparisonctx = &eps->target;
    163:       break;
    164:     case EPS_TARGET_IMAGINARY:
    165:       eps->sc->comparison    = SlepcCompareTargetImaginary;
    166:       eps->sc->comparisonctx = &eps->target;
    167:       break;
    168:     case EPS_ALL:
    169:       eps->sc->comparison    = SlepcCompareSmallestReal;
    170:       eps->sc->comparisonctx = NULL;
    171:       break;
    172:     case EPS_WHICH_USER:
    173:       break;
    174:   }
    175:   eps->sc->map    = NULL;
    176:   eps->sc->mapobj = NULL;

    178:   /* fill sorting criterion for DS */
    179:   DSGetSlepcSC(eps->ds,&sc);
    180:   RGIsTrivial(eps->rg,&istrivial);
    181:   if (eps->which==EPS_ALL) {
    182:     sc->rg            = NULL;
    183:     sc->comparison    = SlepcCompareLargestMagnitude;
    184:     sc->comparisonctx = NULL;
    185:     sc->map           = NULL;
    186:     sc->mapobj        = NULL;
    187:   } else {
    188:     sc->rg            = istrivial? NULL: eps->rg;
    189:     sc->comparison    = eps->sc->comparison;
    190:     sc->comparisonctx = eps->sc->comparisonctx;
    191:     sc->map           = SlepcMap_ST;
    192:     sc->mapobj        = (PetscObject)eps->st;
    193:   }

    195:   /* Build balancing matrix if required */
    196:   if (!eps->ishermitian && (eps->balance==EPS_BALANCE_ONESIDE || eps->balance==EPS_BALANCE_TWOSIDE)) {
    197:     if (!eps->D) {
    198:       BVCreateVec(eps->V,&eps->D);
    199:       PetscLogObjectParent((PetscObject)eps,(PetscObject)eps->D);
    200:     } else {
    201:       VecSet(eps->D,1.0);
    202:     }
    203:     EPSBuildBalance_Krylov(eps);
    204:     STSetBalanceMatrix(eps->st,eps->D);
    205:   }

    207:   /* Setup ST */
    208:   STSetUp(eps->st);

    210: #if defined(PETSC_USE_COMPLEX)
    211:   STGetShift(eps->st,&sigma);
    212:   if (eps->ishermitian && PetscImaginaryPart(sigma) != 0.0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Hermitian problems are not compatible with complex shifts");
    213: #endif
    214:   PetscObjectTypeCompare((PetscObject)eps->st,STCAYLEY,&flg);
    215:   if (flg && eps->problem_type == EPS_PGNHEP) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_SUP,"Cayley spectral transformation is not compatible with PGNHEP");

    217:   /* process deflation and initial vectors */
    218:   if (eps->nds<0) {
    219:     k = -eps->nds;
    220:     BVInsertConstraints(eps->V,&k,eps->defl);
    221:     SlepcBasisDestroy_Private(&eps->nds,&eps->defl);
    222:     eps->nds = k;
    223:     STCheckNullSpace(eps->st,eps->V);
    224:   }
    225:   if (eps->nini<0) {
    226:     k = -eps->nini;
    227:     if (k>eps->ncv) SETERRQ(PetscObjectComm((PetscObject)eps),1,"The number of initial vectors is larger than ncv");
    228:     BVInsertVecs(eps->V,0,&k,eps->IS,PETSC_TRUE);
    229:     SlepcBasisDestroy_Private(&eps->nini,&eps->IS);
    230:     eps->nini = k;
    231:   }

    233:   PetscLogEventEnd(EPS_SetUp,eps,0,0,0);
    234:   eps->state = EPS_STATE_SETUP;
    235:   return(0);
    236: }

    240: /*@
    241:    EPSSetOperators - Sets the matrices associated with the eigenvalue problem.

    243:    Collective on EPS and Mat

    245:    Input Parameters:
    246: +  eps - the eigenproblem solver context
    247: .  A  - the matrix associated with the eigensystem
    248: -  B  - the second matrix in the case of generalized eigenproblems

    250:    Notes:
    251:    To specify a standard eigenproblem, use NULL for parameter B.

    253:    It must be called before EPSSetUp(). If it is called again after EPSSetUp() then
    254:    the EPS object is reset.

    256:    Level: beginner

    258: .seealso: EPSSolve(), EPSSetUp(), EPSReset(), EPSGetST(), STGetOperators()
    259: @*/
    260: PetscErrorCode EPSSetOperators(EPS eps,Mat A,Mat B)
    261: {
    263:   PetscInt       m,n,m0,nmat;
    264:   Mat            mat[2];

    273:   /* Check for square matrices */
    274:   MatGetSize(A,&m,&n);
    275:   if (m!=n) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"A is a non-square matrix");
    276:   if (B) {
    277:     MatGetSize(B,&m0,&n);
    278:     if (m0!=n) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_WRONG,"B is a non-square matrix");
    279:     if (m!=m0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_INCOMP,"Dimensions of A and B do not match");
    280:   }
    281:   if (eps->state) { EPSReset(eps); }
    282:   eps->nrma = 0.0;
    283:   eps->nrmb = 0.0;
    284:   if (!eps->st) { EPSGetST(eps,&eps->st); }
    285:   mat[0] = A;
    286:   if (B) {
    287:     mat[1] = B;
    288:     nmat = 2;
    289:   } else nmat = 1;
    290:   STSetOperators(eps->st,nmat,mat);
    291:   return(0);
    292: }

    296: /*@
    297:    EPSGetOperators - Gets the matrices associated with the eigensystem.

    299:    Collective on EPS and Mat

    301:    Input Parameter:
    302: .  eps - the EPS context

    304:    Output Parameters:
    305: +  A  - the matrix associated with the eigensystem
    306: -  B  - the second matrix in the case of generalized eigenproblems

    308:    Level: intermediate

    310: .seealso: EPSSolve(), EPSGetST(), STGetOperators(), STSetOperators()
    311: @*/
    312: PetscErrorCode EPSGetOperators(EPS eps,Mat *A,Mat *B)
    313: {
    315:   ST             st;
    316:   PetscInt       k;

    320:   EPSGetST(eps,&st);
    321:   if (A) { STGetOperators(st,0,A); }
    322:   if (B) {
    323:     STGetNumMatrices(st,&k);
    324:     if (k==1) B = NULL;
    325:     else {
    326:       STGetOperators(st,1,B);
    327:     }
    328:   }
    329:   return(0);
    330: }

    334: /*@
    335:    EPSSetDeflationSpace - Specify a basis of vectors that constitute the deflation
    336:    space.

    338:    Collective on EPS and Vec

    340:    Input Parameter:
    341: +  eps - the eigenproblem solver context
    342: .  n   - number of vectors
    343: -  v   - set of basis vectors of the deflation space

    345:    Notes:
    346:    When a deflation space is given, the eigensolver seeks the eigensolution
    347:    in the restriction of the problem to the orthogonal complement of this
    348:    space. This can be used for instance in the case that an invariant
    349:    subspace is known beforehand (such as the nullspace of the matrix).

    351:    These vectors do not persist from one EPSSolve() call to the other, so the
    352:    deflation space should be set every time.

    354:    The vectors do not need to be mutually orthonormal, since they are explicitly
    355:    orthonormalized internally.

    357:    Level: intermediate

    359: .seealso: EPSSetInitialSpace()
    360: @*/
    361: PetscErrorCode EPSSetDeflationSpace(EPS eps,PetscInt n,Vec *v)
    362: {

    368:   if (n<0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Argument n out of range");
    369:   SlepcBasisReference_Private(n,v,&eps->nds,&eps->defl);
    370:   if (n>0) eps->state = EPS_STATE_INITIAL;
    371:   return(0);
    372: }

    376: /*@
    377:    EPSSetInitialSpace - Specify a basis of vectors that constitute the initial
    378:    space, that is, the subspace from which the solver starts to iterate.

    380:    Collective on EPS and Vec

    382:    Input Parameter:
    383: +  eps - the eigenproblem solver context
    384: .  n   - number of vectors
    385: -  is  - set of basis vectors of the initial space

    387:    Notes:
    388:    Some solvers start to iterate on a single vector (initial vector). In that case,
    389:    the other vectors are ignored.

    391:    These vectors do not persist from one EPSSolve() call to the other, so the
    392:    initial space should be set every time.

    394:    The vectors do not need to be mutually orthonormal, since they are explicitly
    395:    orthonormalized internally.

    397:    Common usage of this function is when the user can provide a rough approximation
    398:    of the wanted eigenspace. Then, convergence may be faster.

    400:    Level: intermediate

    402: .seealso: EPSSetDeflationSpace()
    403: @*/
    404: PetscErrorCode EPSSetInitialSpace(EPS eps,PetscInt n,Vec *is)
    405: {

    411:   if (n<0) SETERRQ(PetscObjectComm((PetscObject)eps),PETSC_ERR_ARG_OUTOFRANGE,"Argument n cannot be negative");
    412:   SlepcBasisReference_Private(n,is,&eps->nini,&eps->IS);
    413:   if (n>0) eps->state = EPS_STATE_INITIAL;
    414:   return(0);
    415: }

    419: /*
    420:   EPSSetDimensions_Default - Set reasonable values for ncv, mpd if not set
    421:   by the user. This is called at setup.
    422:  */
    423: PetscErrorCode EPSSetDimensions_Default(EPS eps,PetscInt nev,PetscInt *ncv,PetscInt *mpd)
    424: {
    426:   PetscBool      krylov;

    429:   if (*ncv) { /* ncv set */
    430:     PetscObjectTypeCompareAny((PetscObject)eps,&krylov,EPSKRYLOVSCHUR,EPSARNOLDI,EPSLANCZOS,"");
    431:     if (krylov) {
    432:       if (*ncv<nev+1 && !(*ncv==nev && *ncv==eps->n)) SETERRQ(PetscObjectComm((PetscObject)eps),1,"The value of ncv must be at least nev+1");
    433:     } else {
    434:       if (*ncv<nev) SETERRQ(PetscObjectComm((PetscObject)eps),1,"The value of ncv must be at least nev");
    435:     }
    436:   } else if (*mpd) { /* mpd set */
    437:     *ncv = PetscMin(eps->n,nev+(*mpd));
    438:   } else { /* neither set: defaults depend on nev being small or large */
    439:     if (nev<500) *ncv = PetscMin(eps->n,PetscMax(2*nev,nev+15));
    440:     else {
    441:       *mpd = 500;
    442:       *ncv = PetscMin(eps->n,nev+(*mpd));
    443:     }
    444:   }
    445:   if (!*mpd) *mpd = *ncv;
    446:   return(0);
    447: }

    451: /*@
    452:    EPSAllocateSolution - Allocate memory storage for common variables such
    453:    as eigenvalues and eigenvectors.

    455:    Collective on EPS

    457:    Input Parameters:
    458: +  eps   - eigensolver context
    459: -  extra - number of additional positions, used for methods that require a
    460:            working basis slightly larger than ncv

    462:    Developers Note:
    463:    This is PETSC_EXTERN because it may be required by user plugin EPS
    464:    implementations.

    466:    Level: developer
    467: @*/
    468: PetscErrorCode EPSAllocateSolution(EPS eps,PetscInt extra)
    469: {
    471:   PetscInt       oldsize,newc,requested;
    472:   PetscLogDouble cnt;
    473:   Vec            t;

    476:   requested = eps->ncv + extra;

    478:   /* oldsize is zero if this is the first time setup is called */
    479:   BVGetSizes(eps->V,NULL,NULL,&oldsize);
    480:   newc = PetscMax(0,requested-oldsize);

    482:   /* allocate space for eigenvalues and friends */
    483:   if (requested != oldsize || !eps->eigr) {
    484:     if (oldsize) {
    485:       PetscFree4(eps->eigr,eps->eigi,eps->errest,eps->perm);
    486:     }
    487:     PetscMalloc4(requested,&eps->eigr,requested,&eps->eigi,requested,&eps->errest,requested,&eps->perm);
    488:     cnt = 2*newc*sizeof(PetscScalar) + 2*newc*sizeof(PetscReal) + newc*sizeof(PetscInt);
    489:     PetscLogObjectMemory((PetscObject)eps,cnt);
    490:   }

    492:   /* workspace for the case of arbitrary selection */
    493:   if (eps->arbitrary) {
    494:     if (eps->rr) {
    495:       PetscFree2(eps->rr,eps->ri);
    496:     }
    497:     PetscMalloc2(requested,&eps->rr,requested,&eps->ri);
    498:     PetscLogObjectMemory((PetscObject)eps,2*newc*sizeof(PetscScalar));
    499:   }

    501:   /* allocate V */
    502:   if (!eps->V) { EPSGetBV(eps,&eps->V); }
    503:   if (!oldsize) {
    504:     if (!((PetscObject)(eps->V))->type_name) {
    505:       BVSetType(eps->V,BVSVEC);
    506:     }
    507:     STMatCreateVecs(eps->st,&t,NULL);
    508:     BVSetSizesFromVec(eps->V,t,requested);
    509:     VecDestroy(&t);
    510:   } else {
    511:     BVResize(eps->V,requested,PETSC_FALSE);
    512:   }
    513:   return(0);
    514: }