Date: 2023-09-05T10:19:15+00:00

Actual source code: stfunc.c
slepc-3.19.2 2023-09-05
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain

      6:    This file is part of SLEPc.
      7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
      8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      9: */
     10: /*
     11:    The ST interface routines, callable by users
     12: */

     14: #include <slepc/private/stimpl.h>

     16: PetscClassId     ST_CLASSID = 0;
     17: PetscLogEvent    ST_SetUp = 0,ST_ComputeOperator = 0,ST_Apply = 0,ST_ApplyTranspose = 0,ST_MatSetUp = 0,ST_MatMult = 0,ST_MatMultTranspose = 0,ST_MatSolve = 0,ST_MatSolveTranspose = 0;
     18: static PetscBool STPackageInitialized = PETSC_FALSE;

     20: const char *STMatModes[] = {"COPY","INPLACE","SHELL","STMatMode","ST_MATMODE_",NULL};

     22: /*@C
     23:    STFinalizePackage - This function destroys everything in the Slepc interface
     24:    to the ST package. It is called from SlepcFinalize().

     26:    Level: developer

     28: .seealso: SlepcFinalize()
     29: @*/
     30: PetscErrorCode STFinalizePackage(void)
     31: {
     32:   PetscFunctionBegin;
     33:   PetscCall(PetscFunctionListDestroy(&STList));
     34:   STPackageInitialized = PETSC_FALSE;
     35:   STRegisterAllCalled  = PETSC_FALSE;
     36:   PetscFunctionReturn(PETSC_SUCCESS);
     37: }

     39: /*@C
     40:    STInitializePackage - This function initializes everything in the ST package.
     41:    It is called from PetscDLLibraryRegister() when using dynamic libraries, and
     42:    on the first call to STCreate() when using static libraries.

     44:    Level: developer

     46: .seealso: SlepcInitialize()
     47: @*/
     48: PetscErrorCode STInitializePackage(void)
     49: {
     50:   char           logList[256];
     51:   PetscBool      opt,pkg;
     52:   PetscClassId   classids[1];

     54:   PetscFunctionBegin;
     55:   if (STPackageInitialized) PetscFunctionReturn(PETSC_SUCCESS);
     56:   STPackageInitialized = PETSC_TRUE;
     57:   /* Register Classes */
     58:   PetscCall(PetscClassIdRegister("Spectral Transform",&ST_CLASSID));
     59:   /* Register Constructors */
     60:   PetscCall(STRegisterAll());
     61:   /* Register Events */
     62:   PetscCall(PetscLogEventRegister("STSetUp",ST_CLASSID,&ST_SetUp));
     63:   PetscCall(PetscLogEventRegister("STComputeOperatr",ST_CLASSID,&ST_ComputeOperator));
     64:   PetscCall(PetscLogEventRegister("STApply",ST_CLASSID,&ST_Apply));
     65:   PetscCall(PetscLogEventRegister("STApplyTranspose",ST_CLASSID,&ST_ApplyTranspose));
     66:   PetscCall(PetscLogEventRegister("STMatSetUp",ST_CLASSID,&ST_MatSetUp));
     67:   PetscCall(PetscLogEventRegister("STMatMult",ST_CLASSID,&ST_MatMult));
     68:   PetscCall(PetscLogEventRegister("STMatMultTranspose",ST_CLASSID,&ST_MatMultTranspose));
     69:   PetscCall(PetscLogEventRegister("STMatSolve",ST_CLASSID,&ST_MatSolve));
     70:   PetscCall(PetscLogEventRegister("STMatSolveTranspose",ST_CLASSID,&ST_MatSolveTranspose));
     71:   /* Process Info */
     72:   classids[0] = ST_CLASSID;
     73:   PetscCall(PetscInfoProcessClass("st",1,&classids[0]));
     74:   /* Process summary exclusions */
     75:   PetscCall(PetscOptionsGetString(NULL,NULL,"-log_exclude",logList,sizeof(logList),&opt));
     76:   if (opt) {
     77:     PetscCall(PetscStrInList("st",logList,',',&pkg));
     78:     if (pkg) PetscCall(PetscLogEventDeactivateClass(ST_CLASSID));
     79:   }
     80:   /* Register package finalizer */
     81:   PetscCall(PetscRegisterFinalize(STFinalizePackage));
     82:   PetscFunctionReturn(PETSC_SUCCESS);
     83: }

     85: /*@
     86:    STReset - Resets the ST context to the initial state (prior to setup)
     87:    and destroys any allocated Vecs and Mats.

     89:    Collective

     91:    Input Parameter:
     92: .  st - the spectral transformation context

     94:    Level: advanced

     96: .seealso: STDestroy()
     97: @*/
     98: PetscErrorCode STReset(ST st)
     99: {
    100:   PetscFunctionBegin;
    102:   if (!st) PetscFunctionReturn(PETSC_SUCCESS);
    103:   STCheckNotSeized(st,1);
    104:   PetscTryTypeMethod(st,reset);
    105:   if (st->ksp) PetscCall(KSPReset(st->ksp));
    106:   PetscCall(MatDestroyMatrices(PetscMax(2,st->nmat),&st->T));
    107:   PetscCall(MatDestroyMatrices(PetscMax(2,st->nmat),&st->A));
    108:   st->nmat = 0;
    109:   PetscCall(PetscFree(st->Astate));
    110:   PetscCall(MatDestroy(&st->Op));
    111:   PetscCall(MatDestroy(&st->P));
    112:   PetscCall(MatDestroy(&st->Pmat));
    113:   PetscCall(MatDestroyMatrices(st->nsplit,&st->Psplit));
    114:   st->nsplit = 0;
    115:   PetscCall(VecDestroyVecs(st->nwork,&st->work));
    116:   st->nwork = 0;
    117:   PetscCall(VecDestroy(&st->wb));
    118:   PetscCall(VecDestroy(&st->wht));
    119:   PetscCall(VecDestroy(&st->D));
    120:   st->state   = ST_STATE_INITIAL;
    121:   st->opready = PETSC_FALSE;
    122:   PetscFunctionReturn(PETSC_SUCCESS);
    123: }

    125: /*@C
    126:    STDestroy - Destroys ST context that was created with STCreate().

    128:    Collective

    130:    Input Parameter:
    131: .  st - the spectral transformation context

    133:    Level: beginner

    135: .seealso: STCreate(), STSetUp()
    136: @*/
    137: PetscErrorCode STDestroy(ST *st)
    138: {
    139:   PetscFunctionBegin;
    140:   if (!*st) PetscFunctionReturn(PETSC_SUCCESS);
    142:   if (--((PetscObject)(*st))->refct > 0) { *st = NULL; PetscFunctionReturn(PETSC_SUCCESS); }
    143:   PetscCall(STReset(*st));
    144:   PetscTryTypeMethod(*st,destroy);
    145:   PetscCall(KSPDestroy(&(*st)->ksp));
    146:   PetscCall(PetscHeaderDestroy(st));
    147:   PetscFunctionReturn(PETSC_SUCCESS);
    148: }

    150: /*@
    151:    STCreate - Creates a spectral transformation context.

    153:    Collective

    155:    Input Parameter:
    156: .  comm - MPI communicator

    158:    Output Parameter:
    159: .  newst - location to put the spectral transformation context

    161:    Level: beginner

    163: .seealso: STSetUp(), STApply(), STDestroy(), ST
    164: @*/
    165: PetscErrorCode STCreate(MPI_Comm comm,ST *newst)
    166: {
    167:   ST             st;

    169:   PetscFunctionBegin;
    171:   *newst = NULL;
    172:   PetscCall(STInitializePackage());
    173:   PetscCall(SlepcHeaderCreate(st,ST_CLASSID,"ST","Spectral Transformation","ST",comm,STDestroy,STView));

    175:   st->A            = NULL;
    176:   st->nmat         = 0;
    177:   st->sigma        = 0.0;
    178:   st->defsigma     = 0.0;
    179:   st->matmode      = ST_MATMODE_COPY;
    180:   st->str          = UNKNOWN_NONZERO_PATTERN;
    181:   st->transform    = PETSC_FALSE;
    182:   st->D            = NULL;
    183:   st->Pmat         = NULL;
    184:   st->Pmat_set     = PETSC_FALSE;
    185:   st->Psplit       = NULL;
    186:   st->nsplit       = 0;
    187:   st->strp         = UNKNOWN_NONZERO_PATTERN;

    189:   st->ksp          = NULL;
    190:   st->usesksp      = PETSC_FALSE;
    191:   st->nwork        = 0;
    192:   st->work         = NULL;
    193:   st->wb           = NULL;
    194:   st->wht          = NULL;
    195:   st->state        = ST_STATE_INITIAL;
    196:   st->Astate       = NULL;
    197:   st->T            = NULL;
    198:   st->Op           = NULL;
    199:   st->opseized     = PETSC_FALSE;
    200:   st->opready      = PETSC_FALSE;
    201:   st->P            = NULL;
    202:   st->M            = NULL;
    203:   st->sigma_set    = PETSC_FALSE;
    204:   st->asymm        = PETSC_FALSE;
    205:   st->aherm        = PETSC_FALSE;
    206:   st->data         = NULL;

    208:   *newst = st;
    209:   PetscFunctionReturn(PETSC_SUCCESS);
    210: }

    212: /*
    213:    Checks whether the ST matrices are all symmetric or hermitian.
    214: */
    215: static inline PetscErrorCode STMatIsSymmetricKnown(ST st,PetscBool *symm,PetscBool *herm)
    216: {
    217:   PetscInt       i;
    218:   PetscBool      sbaij=PETSC_FALSE,set,flg=PETSC_FALSE;

    220:   PetscFunctionBegin;
    221:   /* check if problem matrices are all sbaij */
    222:   for (i=0;i<st->nmat;i++) {
    223:     PetscCall(PetscObjectTypeCompareAny((PetscObject)st->A[i],&sbaij,MATSEQSBAIJ,MATMPISBAIJ,""));
    224:     if (!sbaij) break;
    225:   }
    226:   /* check if user has set the symmetric flag */
    227:   *symm = PETSC_TRUE;
    228:   for (i=0;i<st->nmat;i++) {
    229:     PetscCall(MatIsSymmetricKnown(st->A[i],&set,&flg));
    230:     if (!set || !flg) { *symm = PETSC_FALSE; break; }
    231:   }
    232:   if (sbaij) *symm = PETSC_TRUE;
    233: #if defined(PETSC_USE_COMPLEX)
    234:   /* check if user has set the hermitian flag */
    235:   *herm = PETSC_TRUE;
    236:   for (i=0;i<st->nmat;i++) {
    237:     PetscCall(MatIsHermitianKnown(st->A[i],&set,&flg));
    238:     if (!set || !flg) { *herm = PETSC_FALSE; break; }
    239:   }
    240: #else
    241:   *herm = *symm;
    242: #endif
    243:   PetscFunctionReturn(PETSC_SUCCESS);
    244: }

    246: /*@
    247:    STSetMatrices - Sets the matrices associated with the eigenvalue problem.

    249:    Collective

    251:    Input Parameters:
    252: +  st - the spectral transformation context
    253: .  n  - number of matrices in array A
    254: -  A  - the array of matrices associated with the eigensystem

    256:    Notes:
    257:    It must be called before STSetUp(). If it is called again after STSetUp() then
    258:    the ST object is reset.

    260:    Level: intermediate

    262: .seealso: STGetMatrix(), STGetNumMatrices(), STSetUp(), STReset()
    263: @*/
    264: PetscErrorCode STSetMatrices(ST st,PetscInt n,Mat A[])
    265: {
    266:   PetscInt       i;
    267:   PetscBool      same=PETSC_TRUE;

    269:   PetscFunctionBegin;
    272:   PetscCheck(n>0,PetscObjectComm((PetscObject)st),PETSC_ERR_ARG_OUTOFRANGE,"Must have one or more matrices, you have %" PetscInt_FMT,n);
    274:   PetscCheckSameComm(st,1,*A,3);
    275:   STCheckNotSeized(st,1);
    276:   PetscCheck(!st->nsplit || st->nsplit==n,PetscObjectComm((PetscObject)st),PETSC_ERR_SUP,"The number of matrices must be the same as in STSetSplitPreconditioner()");

    278:   if (st->state) {
    279:     if (n!=st->nmat) same = PETSC_FALSE;
    280:     for (i=0;same&&i<n;i++) {
    281:       if (A[i]!=st->A[i]) same = PETSC_FALSE;
    282:     }
    283:     if (!same) PetscCall(STReset(st));
    284:   } else same = PETSC_FALSE;
    285:   if (!same) {
    286:     PetscCall(MatDestroyMatrices(PetscMax(2,st->nmat),&st->A));
    287:     PetscCall(PetscCalloc1(PetscMax(2,n),&st->A));
    288:     PetscCall(PetscFree(st->Astate));
    289:     PetscCall(PetscMalloc1(PetscMax(2,n),&st->Astate));
    290:   }
    291:   for (i=0;i<n;i++) {
    293:     PetscCall(PetscObjectReference((PetscObject)A[i]));
    294:     PetscCall(MatDestroy(&st->A[i]));
    295:     st->A[i] = A[i];
    296:     st->Astate[i] = ((PetscObject)A[i])->state;
    297:   }
    298:   if (n==1) {
    299:     st->A[1] = NULL;
    300:     st->Astate[1] = 0;
    301:   }
    302:   st->nmat = n;
    303:   if (same) st->state = ST_STATE_UPDATED;
    304:   else st->state = ST_STATE_INITIAL;
    305:   PetscCheck(!same || !st->Psplit,PetscObjectComm((PetscObject)st),PETSC_ERR_SUP,"Support for changing the matrices while using a split preconditioner is not implemented yet");
    306:   st->opready = PETSC_FALSE;
    307:   if (!same) PetscCall(STMatIsSymmetricKnown(st,&st->asymm,&st->aherm));
    308:   PetscFunctionReturn(PETSC_SUCCESS);
    309: }

    311: /*@
    312:    STGetMatrix - Gets the matrices associated with the original eigensystem.

    314:    Not Collective

    316:    Input Parameters:
    317: +  st - the spectral transformation context
    318: -  k  - the index of the requested matrix (starting in 0)

    320:    Output Parameters:
    321: .  A - the requested matrix

    323:    Level: intermediate

    325: .seealso: STSetMatrices(), STGetNumMatrices()
    326: @*/
    327: PetscErrorCode STGetMatrix(ST st,PetscInt k,Mat *A)
    328: {
    329:   PetscFunctionBegin;
    333:   STCheckMatrices(st,1);
    334:   PetscCheck(k>=0 && k<st->nmat,PetscObjectComm((PetscObject)st),PETSC_ERR_ARG_OUTOFRANGE,"k must be between 0 and %" PetscInt_FMT,st->nmat-1);
    335:   PetscCheck(((PetscObject)st->A[k])->state==st->Astate[k],PetscObjectComm((PetscObject)st),PETSC_ERR_SUP,"Cannot retrieve original matrices (have been modified)");
    336:   *A = st->A[k];
    337:   PetscFunctionReturn(PETSC_SUCCESS);
    338: }

    340: /*@
    341:    STGetMatrixTransformed - Gets the matrices associated with the transformed eigensystem.

    343:    Not Collective

    345:    Input Parameters:
    346: +  st - the spectral transformation context
    347: -  k  - the index of the requested matrix (starting in 0)

    349:    Output Parameters:
    350: .  T - the requested matrix

    352:    Level: developer

    354: .seealso: STGetMatrix(), STGetNumMatrices()
    355: @*/
    356: PetscErrorCode STGetMatrixTransformed(ST st,PetscInt k,Mat *T)
    357: {
    358:   PetscFunctionBegin;
    362:   STCheckMatrices(st,1);
    363:   PetscCheck(k>=0 && k<st->nmat,PetscObjectComm((PetscObject)st),PETSC_ERR_ARG_OUTOFRANGE,"k must be between 0 and %" PetscInt_FMT,st->nmat-1);
    364:   PetscCheck(st->T,PetscObjectComm((PetscObject)st),PETSC_ERR_POINTER,"There are no transformed matrices");
    365:   *T = st->T[k];
    366:   PetscFunctionReturn(PETSC_SUCCESS);
    367: }

    369: /*@
    370:    STGetNumMatrices - Returns the number of matrices stored in the ST.

    372:    Not Collective

    374:    Input Parameter:
    375: .  st - the spectral transformation context

    377:    Output Parameters:
    378: .  n - the number of matrices passed in STSetMatrices()

    380:    Level: intermediate

    382: .seealso: STSetMatrices()
    383: @*/
    384: PetscErrorCode STGetNumMatrices(ST st,PetscInt *n)
    385: {
    386:   PetscFunctionBegin;
    389:   *n = st->nmat;
    390:   PetscFunctionReturn(PETSC_SUCCESS);
    391: }

    393: /*@
    394:    STResetMatrixState - Resets the stored state of the matrices in the ST.

    396:    Logically Collective

    398:    Input Parameter:
    399: .  st - the spectral transformation context

    401:    Note:
    402:    This is useful in solvers where the user matrices are modified during
    403:    the computation, as in nonlinear inverse iteration. The effect is that
    404:    STGetMatrix() will retrieve the modified matrices as if they were
    405:    the matrices originally provided by the user.

    407:    Level: developer

    409: .seealso: STGetMatrix(), EPSPowerSetNonlinear()
    410: @*/
    411: PetscErrorCode STResetMatrixState(ST st)
    412: {
    413:   PetscInt i;

    415:   PetscFunctionBegin;
    417:   for (i=0;i<st->nmat;i++) st->Astate[i] = ((PetscObject)st->A[i])->state;
    418:   PetscFunctionReturn(PETSC_SUCCESS);
    419: }

    421: /*@
    422:    STSetPreconditionerMat - Sets the matrix to be used to build the preconditioner.

    424:    Collective

    426:    Input Parameters:
    427: +  st  - the spectral transformation context
    428: -  mat - the matrix that will be used in constructing the preconditioner

    430:    Notes:
    431:    This matrix will be passed to the internal KSP object (via the last argument
    432:    of KSPSetOperators()) as the matrix to be used when constructing the preconditioner.
    433:    If no matrix is set or mat is set to NULL, A-sigma*B will be used
    434:    to build the preconditioner, being sigma the value set by STSetShift().

    436:    More precisely, this is relevant for spectral transformations that represent
    437:    a rational matrix function, and use a KSP object for the denominator, called
    438:    K in the description of STGetOperator(). It includes also the STPRECOND case.
    439:    If the user has a good approximation to matrix K that can be used to build a
    440:    cheap preconditioner, it can be passed with this function. Note that it affects
    441:    only the Pmat argument of KSPSetOperators(), not the Amat argument.

    443:    If a preconditioner matrix is set, the default is to use an iterative KSP
    444:    rather than a direct method.

    446:    An alternative to pass an approximation of A-sigma*B with this function is
    447:    to provide approximations of A and B via STSetSplitPreconditioner(). The
    448:    difference is that when sigma changes the preconditioner is recomputed.

    450:    Use NULL to remove a previously set matrix.

    452:    Level: advanced

    454: .seealso: STGetPreconditionerMat(), STSetShift(), STGetOperator(), STSetSplitPreconditioner()
    455: @*/
    456: PetscErrorCode STSetPreconditionerMat(ST st,Mat mat)
    457: {
    458:   PetscFunctionBegin;
    460:   if (mat) {
    462:     PetscCheckSameComm(st,1,mat,2);
    463:   }
    464:   STCheckNotSeized(st,1);
    465:   PetscCheck(!mat || !st->Psplit,PetscObjectComm((PetscObject)st),PETSC_ERR_SUP,"Cannot call both STSetPreconditionerMat and STSetSplitPreconditioner");
    466:   if (mat) PetscCall(PetscObjectReference((PetscObject)mat));
    467:   PetscCall(MatDestroy(&st->Pmat));
    468:   st->Pmat     = mat;
    469:   st->Pmat_set = mat? PETSC_TRUE: PETSC_FALSE;
    470:   st->state    = ST_STATE_INITIAL;
    471:   st->opready  = PETSC_FALSE;
    472:   PetscFunctionReturn(PETSC_SUCCESS);
    473: }

    475: /*@
    476:    STGetPreconditionerMat - Returns the matrix previously set by STSetPreconditionerMat().

    478:    Not Collective

    480:    Input Parameter:
    481: .  st - the spectral transformation context

    483:    Output Parameter:
    484: .  mat - the matrix that will be used in constructing the preconditioner or
    485:    NULL if no matrix was set by STSetPreconditionerMat().

    487:    Level: advanced

    489: .seealso: STSetPreconditionerMat()
    490: @*/
    491: PetscErrorCode STGetPreconditionerMat(ST st,Mat *mat)
    492: {
    493:   PetscFunctionBegin;
    496:   *mat = st->Pmat_set? st->Pmat: NULL;
    497:   PetscFunctionReturn(PETSC_SUCCESS);
    498: }

    500: /*@
    501:    STSetSplitPreconditioner - Sets the matrices from which to build the preconditioner
    502:    in split form.

    504:    Collective

    506:    Input Parameters:
    507: +  st     - the spectral transformation context
    508: .  n      - number of matrices
    509: .  Psplit - array of matrices
    510: -  strp   - structure flag for Psplit matrices

    512:    Notes:
    513:    The number of matrices passed here must be the same as in STSetMatrices().

    515:    For linear eigenproblems, the preconditioner matrix is computed as
    516:    Pmat(sigma) = A0-sigma*B0, where A0 and B0 are approximations of A and B
    517:    (the eigenproblem matrices) provided via the Psplit array in this function.
    518:    Compared to STSetPreconditionerMat(), this function allows setting a preconditioner
    519:    in a way that is independent of the shift sigma. Whenever the value of sigma
    520:    changes the preconditioner is recomputed.

    522:    Similarly, for polynomial eigenproblems the matrix for the preconditioner
    523:    is expressed as Pmat(sigma) = sum_i Psplit_i*phi_i(sigma), for i=1,...,n, where
    524:    the phi_i's are the polynomial basis functions.

    526:    The structure flag provides information about the relative nonzero pattern of the
    527:    Psplit_i matrices, in the same way as in STSetMatStructure().

    529:    Use n=0 to reset a previously set split preconditioner.

    531:    Level: advanced

    533: .seealso: STGetSplitPreconditionerTerm(), STGetSplitPreconditionerInfo(), STSetPreconditionerMat(), STSetMatrices(), STSetMatStructure()
    534: @*/
    535: PetscErrorCode STSetSplitPreconditioner(ST st,PetscInt n,Mat Psplit[],MatStructure strp)
    536: {
    537:   PetscInt       i,N=0,M,M0=0,mloc,nloc,mloc0=0;

    539:   PetscFunctionBegin;
    542:   PetscCheck(n>=0,PetscObjectComm((PetscObject)st),PETSC_ERR_ARG_OUTOFRANGE,"Negative value of n = %" PetscInt_FMT,n);
    543:   PetscCheck(!n || !st->Pmat_set,PetscObjectComm((PetscObject)st),PETSC_ERR_SUP,"Cannot call both STSetPreconditionerMat and STSetSplitPreconditioner");
    544:   PetscCheck(!n || !st->nmat || st->nmat==n,PetscObjectComm((PetscObject)st),PETSC_ERR_SUP,"The number of matrices must be the same as in STSetMatrices()");
    547:   STCheckNotSeized(st,1);

    549:   for (i=0;i<n;i++) {
    551:     PetscCheckSameComm(st,1,Psplit[i],3);
    552:     PetscCall(MatGetSize(Psplit[i],&M,&N));
    553:     PetscCall(MatGetLocalSize(Psplit[i],&mloc,&nloc));
    554:     PetscCheck(M==N,PetscObjectComm((PetscObject)st),PETSC_ERR_ARG_WRONG,"Psplit[%" PetscInt_FMT "] is a non-square matrix (%" PetscInt_FMT " rows, %" PetscInt_FMT " cols)",i,M,N);
    555:     PetscCheck(mloc==nloc,PetscObjectComm((PetscObject)st),PETSC_ERR_ARG_WRONG,"Psplit[%" PetscInt_FMT "] does not have equal row and column local sizes (%" PetscInt_FMT ", %" PetscInt_FMT ")",i,mloc,nloc);
    556:     if (!i) { M0 = M; mloc0 = mloc; }
    557:     PetscCheck(M==M0,PetscObjectComm((PetscObject)st),PETSC_ERR_ARG_INCOMP,"Dimensions of Psplit[%" PetscInt_FMT "] do not match with previous matrices (%" PetscInt_FMT ", %" PetscInt_FMT ")",i,M,M0);
    558:     PetscCheck(mloc==mloc0,PetscObjectComm((PetscObject)st),PETSC_ERR_ARG_INCOMP,"Local dimensions of Psplit[%" PetscInt_FMT "] do not match with previous matrices (%" PetscInt_FMT ", %" PetscInt_FMT ")",i,mloc,mloc0);
    559:     PetscCall(PetscObjectReference((PetscObject)Psplit[i]));
    560:   }

    562:   if (st->Psplit) PetscCall(MatDestroyMatrices(st->nsplit,&st->Psplit));

    564:   /* allocate space and copy matrices */
    565:   if (n) {
    566:     PetscCall(PetscMalloc1(n,&st->Psplit));
    567:     for (i=0;i<n;i++) st->Psplit[i] = Psplit[i];
    568:   }
    569:   st->nsplit = n;
    570:   st->strp   = strp;
    571:   st->state  = ST_STATE_INITIAL;
    572:   PetscFunctionReturn(PETSC_SUCCESS);
    573: }

    575: /*@
    576:    STGetSplitPreconditionerTerm - Gets the matrices associated with
    577:    the split preconditioner.

    579:    Not Collective

    581:    Input Parameters:
    582: +  st - the spectral transformation context
    583: -  k  - the index of the requested matrix (starting in 0)

    585:    Output Parameter:
    586: .  Psplit - the returned matrix

    588:    Level: advanced

    590: .seealso: STSetSplitPreconditioner(), STGetSplitPreconditionerInfo()
    591: @*/
    592: PetscErrorCode STGetSplitPreconditionerTerm(ST st,PetscInt k,Mat *Psplit)
    593: {
    594:   PetscFunctionBegin;
    598:   PetscCheck(k>=0 && k<st->nsplit,PetscObjectComm((PetscObject)st),PETSC_ERR_ARG_OUTOFRANGE,"k must be between 0 and %" PetscInt_FMT,st->nsplit-1);
    599:   PetscCheck(st->Psplit,PetscObjectComm((PetscObject)st),PETSC_ERR_ORDER,"You have not called STSetSplitPreconditioner()");
    600:   *Psplit = st->Psplit[k];
    601:   PetscFunctionReturn(PETSC_SUCCESS);
    602: }

    604: /*@
    605:    STGetSplitPreconditionerInfo - Returns the number of matrices of the split
    606:    preconditioner, as well as the structure flag.

    608:    Not Collective

    610:    Input Parameter:
    611: .  st - the spectral transformation context

    613:    Output Parameters:
    614: +  n    - the number of matrices passed in STSetSplitPreconditioner()
    615: -  strp - the matrix structure flag passed in STSetSplitPreconditioner()

    617:    Level: advanced

    619: .seealso: STSetSplitPreconditioner(), STGetSplitPreconditionerTerm()
    620: @*/
    621: PetscErrorCode STGetSplitPreconditionerInfo(ST st,PetscInt *n,MatStructure *strp)
    622: {
    623:   PetscFunctionBegin;
    625:   if (n)    *n    = st->nsplit;
    626:   if (strp) *strp = st->strp;
    627:   PetscFunctionReturn(PETSC_SUCCESS);
    628: }

    630: /*@
    631:    STSetShift - Sets the shift associated with the spectral transformation.

    633:    Collective

    635:    Input Parameters:
    636: +  st - the spectral transformation context
    637: -  shift - the value of the shift

    639:    Notes:
    640:    In some spectral transformations, changing the shift may have associated
    641:    a lot of work, for example recomputing a factorization.

    643:    This function is normally not directly called by users, since the shift is
    644:    indirectly set by EPSSetTarget().

    646:    Level: intermediate

    648: .seealso: EPSSetTarget(), STGetShift(), STSetDefaultShift()
    649: @*/
    650: PetscErrorCode STSetShift(ST st,PetscScalar shift)
    651: {
    652:   PetscFunctionBegin;
    656:   if (st->sigma != shift) {
    657:     STCheckNotSeized(st,1);
    658:     if (st->state==ST_STATE_SETUP) PetscTryTypeMethod(st,setshift,shift);
    659:     st->sigma = shift;
    660:   }
    661:   st->sigma_set = PETSC_TRUE;
    662:   PetscFunctionReturn(PETSC_SUCCESS);
    663: }

    665: /*@
    666:    STGetShift - Gets the shift associated with the spectral transformation.

    668:    Not Collective

    670:    Input Parameter:
    671: .  st - the spectral transformation context

    673:    Output Parameter:
    674: .  shift - the value of the shift

    676:    Level: intermediate

    678: .seealso: STSetShift()
    679: @*/
    680: PetscErrorCode STGetShift(ST st,PetscScalar* shift)
    681: {
    682:   PetscFunctionBegin;
    685:   *shift = st->sigma;
    686:   PetscFunctionReturn(PETSC_SUCCESS);
    687: }

    689: /*@
    690:    STSetDefaultShift - Sets the value of the shift that should be employed if
    691:    the user did not specify one.

    693:    Logically Collective

    695:    Input Parameters:
    696: +  st - the spectral transformation context
    697: -  defaultshift - the default value of the shift

    699:    Level: developer

    701: .seealso: STSetShift()
    702: @*/
    703: PetscErrorCode STSetDefaultShift(ST st,PetscScalar defaultshift)
    704: {
    705:   PetscFunctionBegin;
    708:   if (st->defsigma != defaultshift) {
    709:     st->defsigma = defaultshift;
    710:     st->state    = ST_STATE_INITIAL;
    711:     st->opready  = PETSC_FALSE;
    712:   }
    713:   PetscFunctionReturn(PETSC_SUCCESS);
    714: }

    716: /*@
    717:    STScaleShift - Multiply the shift with a given factor.

    719:    Logically Collective

    721:    Input Parameters:
    722: +  st     - the spectral transformation context
    723: -  factor - the scaling factor

    725:    Note:
    726:    This function does not update the transformation matrices, as opposed to
    727:    STSetShift().

    729:    Level: developer

    731: .seealso: STSetShift()
    732: @*/
    733: PetscErrorCode STScaleShift(ST st,PetscScalar factor)
    734: {
    735:   PetscFunctionBegin;
    738:   st->sigma *= factor;
    739:   PetscFunctionReturn(PETSC_SUCCESS);
    740: }

    742: /*@
    743:    STSetBalanceMatrix - Sets the diagonal matrix to be used for balancing.

    745:    Collective

    747:    Input Parameters:
    748: +  st - the spectral transformation context
    749: -  D  - the diagonal matrix (represented as a vector)

    751:    Notes:
    752:    If this matrix is set, STApply will effectively apply D*OP*D^{-1}. Use NULL
    753:    to reset a previously passed D.

    755:    Balancing is usually set via EPSSetBalance, but the advanced user may use
    756:    this function to bypass the usual balancing methods.

    758:    Level: developer

    760: .seealso: EPSSetBalance(), STApply(), STGetBalanceMatrix()
    761: @*/
    762: PetscErrorCode STSetBalanceMatrix(ST st,Vec D)
    763: {
    764:   PetscFunctionBegin;
    766:   if (st->D == D) PetscFunctionReturn(PETSC_SUCCESS);
    767:   STCheckNotSeized(st,1);
    768:   if (D) {
    770:     PetscCheckSameComm(st,1,D,2);
    771:     PetscCall(PetscObjectReference((PetscObject)D));
    772:   }
    773:   PetscCall(VecDestroy(&st->D));
    774:   st->D = D;
    775:   st->state   = ST_STATE_INITIAL;
    776:   st->opready = PETSC_FALSE;
    777:   PetscFunctionReturn(PETSC_SUCCESS);
    778: }

    780: /*@
    781:    STGetBalanceMatrix - Gets the balance matrix used by the spectral transformation.

    783:    Not Collective

    785:    Input Parameter:
    786: .  st - the spectral transformation context

    788:    Output Parameter:
    789: .  D  - the diagonal matrix (represented as a vector)

    791:    Note:
    792:    If the matrix was not set, a null pointer will be returned.

    794:    Level: developer

    796: .seealso: STSetBalanceMatrix()
    797: @*/
    798: PetscErrorCode STGetBalanceMatrix(ST st,Vec *D)
    799: {
    800:   PetscFunctionBegin;
    803:   *D = st->D;
    804:   PetscFunctionReturn(PETSC_SUCCESS);
    805: }

    807: /*@C
    808:    STMatCreateVecs - Get vector(s) compatible with the ST matrices.

    810:    Collective

    812:    Input Parameter:
    813: .  st - the spectral transformation context

    815:    Output Parameters:
    816: +  right - (optional) vector that the matrix can be multiplied against
    817: -  left  - (optional) vector that the matrix vector product can be stored in

    819:    Level: developer

    821: .seealso: STMatCreateVecsEmpty()
    822: @*/
    823: PetscErrorCode STMatCreateVecs(ST st,Vec *right,Vec *left)
    824: {
    825:   PetscFunctionBegin;
    826:   STCheckMatrices(st,1);
    827:   PetscCall(MatCreateVecs(st->A[0],right,left));
    828:   PetscFunctionReturn(PETSC_SUCCESS);
    829: }

    831: /*@C
    832:    STMatCreateVecsEmpty - Get vector(s) compatible with the ST matrices, i.e. with the same
    833:    parallel layout, but without internal array.

    835:    Collective

    837:    Input Parameter:
    838: .  st - the spectral transformation context

    840:    Output Parameters:
    841: +  right - (optional) vector that the matrix can be multiplied against
    842: -  left  - (optional) vector that the matrix vector product can be stored in

    844:    Level: developer

    846: .seealso: STMatCreateVecs(), MatCreateVecsEmpty()
    847: @*/
    848: PetscErrorCode STMatCreateVecsEmpty(ST st,Vec *right,Vec *left)
    849: {
    850:   PetscFunctionBegin;
    851:   STCheckMatrices(st,1);
    852:   PetscCall(MatCreateVecsEmpty(st->A[0],right,left));
    853:   PetscFunctionReturn(PETSC_SUCCESS);
    854: }

    856: /*@
    857:    STMatGetSize - Returns the number of rows and columns of the ST matrices.

    859:    Not Collective

    861:    Input Parameter:
    862: .  st - the spectral transformation context

    864:    Output Parameters:
    865: +  m - the number of global rows
    866: -  n - the number of global columns

    868:    Level: developer

    870: .seealso: STMatGetLocalSize()
    871: @*/
    872: PetscErrorCode STMatGetSize(ST st,PetscInt *m,PetscInt *n)
    873: {
    874:   PetscFunctionBegin;
    875:   STCheckMatrices(st,1);
    876:   PetscCall(MatGetSize(st->A[0],m,n));
    877:   PetscFunctionReturn(PETSC_SUCCESS);
    878: }

    880: /*@
    881:    STMatGetLocalSize - Returns the number of local rows and columns of the ST matrices.

    883:    Not Collective

    885:    Input Parameter:
    886: .  st - the spectral transformation context

    888:    Output Parameters:
    889: +  m - the number of local rows
    890: -  n - the number of local columns

    892:    Level: developer

    894: .seealso: STMatGetSize()
    895: @*/
    896: PetscErrorCode STMatGetLocalSize(ST st,PetscInt *m,PetscInt *n)
    897: {
    898:   PetscFunctionBegin;
    899:   STCheckMatrices(st,1);
    900:   PetscCall(MatGetLocalSize(st->A[0],m,n));
    901:   PetscFunctionReturn(PETSC_SUCCESS);
    902: }

    904: /*@C
    905:    STSetOptionsPrefix - Sets the prefix used for searching for all
    906:    ST options in the database.

    908:    Logically Collective

    910:    Input Parameters:
    911: +  st     - the spectral transformation context
    912: -  prefix - the prefix string to prepend to all ST option requests

    914:    Notes:
    915:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    916:    The first character of all runtime options is AUTOMATICALLY the
    917:    hyphen.

    919:    Level: advanced

    921: .seealso: STAppendOptionsPrefix(), STGetOptionsPrefix()
    922: @*/
    923: PetscErrorCode STSetOptionsPrefix(ST st,const char *prefix)
    924: {
    925:   PetscFunctionBegin;
    927:   if (!st->ksp) PetscCall(STGetKSP(st,&st->ksp));
    928:   PetscCall(KSPSetOptionsPrefix(st->ksp,prefix));
    929:   PetscCall(KSPAppendOptionsPrefix(st->ksp,"st_"));
    930:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)st,prefix));
    931:   PetscFunctionReturn(PETSC_SUCCESS);
    932: }

    934: /*@C
    935:    STAppendOptionsPrefix - Appends to the prefix used for searching for all
    936:    ST options in the database.

    938:    Logically Collective

    940:    Input Parameters:
    941: +  st     - the spectral transformation context
    942: -  prefix - the prefix string to prepend to all ST option requests

    944:    Notes:
    945:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    946:    The first character of all runtime options is AUTOMATICALLY the
    947:    hyphen.

    949:    Level: advanced

    951: .seealso: STSetOptionsPrefix(), STGetOptionsPrefix()
    952: @*/
    953: PetscErrorCode STAppendOptionsPrefix(ST st,const char *prefix)
    954: {
    955:   PetscFunctionBegin;
    957:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)st,prefix));
    958:   if (!st->ksp) PetscCall(STGetKSP(st,&st->ksp));
    959:   PetscCall(KSPSetOptionsPrefix(st->ksp,((PetscObject)st)->prefix));
    960:   PetscCall(KSPAppendOptionsPrefix(st->ksp,"st_"));
    961:   PetscFunctionReturn(PETSC_SUCCESS);
    962: }

    964: /*@C
    965:    STGetOptionsPrefix - Gets the prefix used for searching for all
    966:    ST options in the database.

    968:    Not Collective

    970:    Input Parameters:
    971: .  st - the spectral transformation context

    973:    Output Parameters:
    974: .  prefix - pointer to the prefix string used, is returned

    976:    Note:
    977:    On the Fortran side, the user should pass in a string 'prefix' of
    978:    sufficient length to hold the prefix.

    980:    Level: advanced

    982: .seealso: STSetOptionsPrefix(), STAppendOptionsPrefix()
    983: @*/
    984: PetscErrorCode STGetOptionsPrefix(ST st,const char *prefix[])
    985: {
    986:   PetscFunctionBegin;
    989:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)st,prefix));
    990:   PetscFunctionReturn(PETSC_SUCCESS);
    991: }

    993: /*@C
    994:    STView - Prints the ST data structure.

    996:    Collective

    998:    Input Parameters:
    999: +  st - the ST context
    1000: -  viewer - optional visualization context

    1002:    Note:
    1003:    The available visualization contexts include
    1004: +     PETSC_VIEWER_STDOUT_SELF - standard output (default)
    1005: -     PETSC_VIEWER_STDOUT_WORLD - synchronized standard
    1006:          output where only the first processor opens
    1007:          the file.  All other processors send their
    1008:          data to the first processor to print.

    1010:    The user can open an alternative visualization contexts with
    1011:    PetscViewerASCIIOpen() (output to a specified file).

    1013:    Level: beginner

    1015: .seealso: EPSView()
    1016: @*/
    1017: PetscErrorCode STView(ST st,PetscViewer viewer)
    1018: {
    1019:   STType         cstr;
    1020:   char           str[50];
    1021:   PetscBool      isascii,isstring;

    1023:   PetscFunctionBegin;
    1025:   if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)st),&viewer));
    1027:   PetscCheckSameComm(st,1,viewer,2);

    1029:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii));
    1030:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring));
    1031:   if (isascii) {
    1032:     PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)st,viewer));
    1033:     PetscCall(PetscViewerASCIIPushTab(viewer));
    1034:     PetscTryTypeMethod(st,view,viewer);
    1035:     PetscCall(PetscViewerASCIIPopTab(viewer));
    1036:     PetscCall(SlepcSNPrintfScalar(str,sizeof(str),st->sigma,PETSC_FALSE));
    1037:     PetscCall(PetscViewerASCIIPrintf(viewer,"  shift: %s\n",str));
    1038:     PetscCall(PetscViewerASCIIPrintf(viewer,"  number of matrices: %" PetscInt_FMT "\n",st->nmat));
    1039:     switch (st->matmode) {
    1040:     case ST_MATMODE_COPY:
    1041:       break;
    1042:     case ST_MATMODE_INPLACE:
    1043:       PetscCall(PetscViewerASCIIPrintf(viewer,"  shifting the matrix and unshifting at exit\n"));
    1044:       break;
    1045:     case ST_MATMODE_SHELL:
    1046:       PetscCall(PetscViewerASCIIPrintf(viewer,"  using a shell matrix\n"));
    1047:       break;
    1048:     }
    1049:     if (st->nmat>1 && st->matmode != ST_MATMODE_SHELL) PetscCall(PetscViewerASCIIPrintf(viewer,"  nonzero pattern of the matrices: %s\n",MatStructures[st->str]));
    1050:     if (st->Psplit) PetscCall(PetscViewerASCIIPrintf(viewer,"  using split preconditioner matrices with %s\n",MatStructures[st->strp]));
    1051:     if (st->transform && st->nmat>2) PetscCall(PetscViewerASCIIPrintf(viewer,"  computing transformed matrices\n"));
    1052:   } else if (isstring) {
    1053:     PetscCall(STGetType(st,&cstr));
    1054:     PetscCall(PetscViewerStringSPrintf(viewer," %-7.7s",cstr));
    1055:     PetscTryTypeMethod(st,view,viewer);
    1056:   }
    1057:   if (st->usesksp) {
    1058:     if (!st->ksp) PetscCall(STGetKSP(st,&st->ksp));
    1059:     PetscCall(PetscViewerASCIIPushTab(viewer));
    1060:     PetscCall(KSPView(st->ksp,viewer));
    1061:     PetscCall(PetscViewerASCIIPopTab(viewer));
    1062:   }
    1063:   PetscFunctionReturn(PETSC_SUCCESS);
    1064: }

    1066: /*@C
    1067:    STViewFromOptions - View from options

    1069:    Collective

    1071:    Input Parameters:
    1072: +  st   - the spectral transformation context
    1073: .  obj  - optional object
    1074: -  name - command line option

    1076:    Level: intermediate

    1078: .seealso: STView(), STCreate()
    1079: @*/
    1080: PetscErrorCode STViewFromOptions(ST st,PetscObject obj,const char name[])
    1081: {
    1082:   PetscFunctionBegin;
    1084:   PetscCall(PetscObjectViewFromOptions((PetscObject)st,obj,name));
    1085:   PetscFunctionReturn(PETSC_SUCCESS);
    1086: }

    1088: /*@C
    1089:    STRegister - Adds a method to the spectral transformation package.

    1091:    Not Collective

    1093:    Input Parameters:
    1094: +  name - name of a new user-defined transformation
    1095: -  function - routine to create method context

    1097:    Notes:
    1098:    STRegister() may be called multiple times to add several user-defined
    1099:    spectral transformations.

    1101:    Example Usage:
    1102: .vb
    1103:     STRegister("my_transform",MyTransformCreate);
    1104: .ve

    1106:    Then, your spectral transform can be chosen with the procedural interface via
    1107: $     STSetType(st,"my_transform")
    1108:    or at runtime via the option
    1109: $     -st_type my_transform

    1111:    Level: advanced

    1113: .seealso: STRegisterAll()
    1114: @*/
    1115: PetscErrorCode STRegister(const char *name,PetscErrorCode (*function)(ST))
    1116: {
    1117:   PetscFunctionBegin;
    1118:   PetscCall(STInitializePackage());
    1119:   PetscCall(PetscFunctionListAdd(&STList,name,function));
    1120:   PetscFunctionReturn(PETSC_SUCCESS);
    1121: }