Date: 2026-03-09T09:12:11+00:00

Actual source code: dsbasic.c

      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:    Basic DS routines
     12: */

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

     16: PetscFunctionList DSList = NULL;
     17: PetscBool         DSRegisterAllCalled = PETSC_FALSE;
     18: PetscClassId      DS_CLASSID = 0;
     19: PetscLogEvent     DS_Solve = 0,DS_Vectors = 0,DS_Synchronize = 0,DS_Other = 0;
     20: static PetscBool  DSPackageInitialized = PETSC_FALSE;

     22: const char *DSStateTypes[] = {"RAW","INTERMEDIATE","CONDENSED","TRUNCATED","DSStateType","DS_STATE_",NULL};
     23: const char *DSParallelTypes[] = {"REDUNDANT","SYNCHRONIZED","DISTRIBUTED","DSParallelType","DS_PARALLEL_",NULL};
     24: const char *DSMatName[DS_NUM_MAT] = {"A","B","C","T","D","Q","Z","X","Y","U","V","W","E0","E1","E2","E3","E4","E5","E6","E7","E8","E9"};
     25: DSMatType  DSMatExtra[DS_NUM_EXTRA] = {DS_MAT_E0,DS_MAT_E1,DS_MAT_E2,DS_MAT_E3,DS_MAT_E4,DS_MAT_E5,DS_MAT_E6,DS_MAT_E7,DS_MAT_E8,DS_MAT_E9};

     27: /*@C
     28:    DSFinalizePackage - This function destroys everything in the SLEPc interface
     29:    to the `DS` package. It is called from `SlepcFinalize()`.

     31:    Level: developer

     33: .seealso: [](sec:ds), `SlepcFinalize()`, `DSInitializePackage()`
     34: @*/
     35: PetscErrorCode DSFinalizePackage(void)
     36: {
     37:   PetscFunctionBegin;
     38:   PetscCall(PetscFunctionListDestroy(&DSList));
     39:   DSPackageInitialized = PETSC_FALSE;
     40:   DSRegisterAllCalled  = PETSC_FALSE;
     41:   PetscFunctionReturn(PETSC_SUCCESS);
     42: }

     44: /*@C
     45:    DSInitializePackage - This function initializes everything in the `DS` package.
     46:    It is called from `PetscDLLibraryRegister_slepc()` when using dynamic libraries, and
     47:    on the first call to `DSCreate()` when using shared or static libraries.

     49:    Note:
     50:    This function never needs to be called by SLEPc users.

     52:    Level: developer

     54: .seealso: [](sec:ds), `DS`, `SlepcInitialize()`, `DSFinalizePackage()`
     55: @*/
     56: PetscErrorCode DSInitializePackage(void)
     57: {
     58:   char           logList[256];
     59:   PetscBool      opt,pkg;
     60:   PetscClassId   classids[1];

     62:   PetscFunctionBegin;
     63:   if (DSPackageInitialized) PetscFunctionReturn(PETSC_SUCCESS);
     64:   DSPackageInitialized = PETSC_TRUE;
     65:   /* Register Classes */
     66:   PetscCall(PetscClassIdRegister("Direct Solver",&DS_CLASSID));
     67:   /* Register Constructors */
     68:   PetscCall(DSRegisterAll());
     69:   /* Register Events */
     70:   PetscCall(PetscLogEventRegister("DSSolve",DS_CLASSID,&DS_Solve));
     71:   PetscCall(PetscLogEventRegister("DSVectors",DS_CLASSID,&DS_Vectors));
     72:   PetscCall(PetscLogEventRegister("DSSynchronize",DS_CLASSID,&DS_Synchronize));
     73:   PetscCall(PetscLogEventRegister("DSOther",DS_CLASSID,&DS_Other));
     74:   /* Process Info */
     75:   classids[0] = DS_CLASSID;
     76:   PetscCall(PetscInfoProcessClass("ds",1,&classids[0]));
     77:   /* Process summary exclusions */
     78:   PetscCall(PetscOptionsGetString(NULL,NULL,"-log_exclude",logList,sizeof(logList),&opt));
     79:   if (opt) {
     80:     PetscCall(PetscStrInList("ds",logList,',',&pkg));
     81:     if (pkg) PetscCall(PetscLogEventDeactivateClass(DS_CLASSID));
     82:   }
     83:   /* Register package finalizer */
     84:   PetscCall(PetscRegisterFinalize(DSFinalizePackage));
     85:   PetscFunctionReturn(PETSC_SUCCESS);
     86: }

     88: /*@
     89:    DSCreate - Creates a `DS` context.

     91:    Collective

     93:    Input Parameter:
     94: .  comm - MPI communicator

     96:    Output Parameter:
     97: .  newds - location to put the `DS` context

     99:    Level: beginner

    101:    Note:
    102:    `DS` objects are not intended for normal users but only for
    103:    advanced user that for instance implement their own solvers.

    105: .seealso: [](sec:ds), `DSDestroy()`, `DS`
    106: @*/
    107: PetscErrorCode DSCreate(MPI_Comm comm,DS *newds)
    108: {
    109:   DS             ds;
    110:   PetscInt       i;

    112:   PetscFunctionBegin;
    113:   PetscAssertPointer(newds,2);
    114:   PetscCall(DSInitializePackage());
    115:   PetscCall(SlepcHeaderCreate(ds,DS_CLASSID,"DS","Direct Solver (or Dense System)","DS",comm,DSDestroy,DSView));

    117:   ds->state         = DS_STATE_RAW;
    118:   ds->method        = 0;
    119:   ds->compact       = PETSC_FALSE;
    120:   ds->refined       = PETSC_FALSE;
    121:   ds->extrarow      = PETSC_FALSE;
    122:   ds->ld            = 0;
    123:   ds->l             = 0;
    124:   ds->n             = 0;
    125:   ds->k             = 0;
    126:   ds->t             = 0;
    127:   ds->bs            = 1;
    128:   ds->sc            = NULL;
    129:   ds->pmode         = DS_PARALLEL_REDUNDANT;

    131:   for (i=0;i<DS_NUM_MAT;i++) ds->omat[i] = NULL;
    132:   ds->perm          = NULL;
    133:   ds->data          = NULL;
    134:   ds->scset         = PETSC_FALSE;
    135:   ds->work          = NULL;
    136:   ds->rwork         = NULL;
    137:   ds->iwork         = NULL;
    138:   ds->lwork         = 0;
    139:   ds->lrwork        = 0;
    140:   ds->liwork        = 0;

    142:   *newds = ds;
    143:   PetscFunctionReturn(PETSC_SUCCESS);
    144: }

    146: /*@
    147:    DSSetOptionsPrefix - Sets the prefix used for searching for all
    148:    `DS` options in the database.

    150:    Logically Collective

    152:    Input Parameters:
    153: +  ds - the direct solver context
    154: -  prefix - the prefix string to prepend to all `DS` option requests

    156:    Notes:
    157:    A hyphen (-) must NOT be given at the beginning of the prefix name.
    158:    The first character of all runtime options is AUTOMATICALLY the
    159:    hyphen.

    161:    Level: advanced

    163: .seealso: [](sec:ds), `DSAppendOptionsPrefix()`
    164: @*/
    165: PetscErrorCode DSSetOptionsPrefix(DS ds,const char prefix[])
    166: {
    167:   PetscFunctionBegin;
    169:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)ds,prefix));
    170:   PetscFunctionReturn(PETSC_SUCCESS);
    171: }

    173: /*@
    174:    DSAppendOptionsPrefix - Appends to the prefix used for searching for all
    175:    `DS` options in the database.

    177:    Logically Collective

    179:    Input Parameters:
    180: +  ds - the direct solver context
    181: -  prefix - the prefix string to prepend to all DS option requests

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

    187:    Level: advanced

    189: .seealso: [](sec:ds), `DSSetOptionsPrefix()`
    190: @*/
    191: PetscErrorCode DSAppendOptionsPrefix(DS ds,const char prefix[])
    192: {
    193:   PetscFunctionBegin;
    195:   PetscCall(PetscObjectAppendOptionsPrefix((PetscObject)ds,prefix));
    196:   PetscFunctionReturn(PETSC_SUCCESS);
    197: }

    199: /*@
    200:    DSGetOptionsPrefix - Gets the prefix used for searching for all
    201:    `DS` options in the database.

    203:    Not Collective

    205:    Input Parameter:
    206: .  ds - the direct solver context

    208:    Output Parameter:
    209: .  prefix - pointer to the prefix string used is returned

    211:    Level: advanced

    213: .seealso: [](sec:ds), `DSSetOptionsPrefix()`, `DSAppendOptionsPrefix()`
    214: @*/
    215: PetscErrorCode DSGetOptionsPrefix(DS ds,const char *prefix[])
    216: {
    217:   PetscFunctionBegin;
    219:   PetscAssertPointer(prefix,2);
    220:   PetscCall(PetscObjectGetOptionsPrefix((PetscObject)ds,prefix));
    221:   PetscFunctionReturn(PETSC_SUCCESS);
    222: }

    224: /*@
    225:    DSSetType - Selects the type for the DS object.

    227:    Logically Collective

    229:    Input Parameters:
    230: +  ds   - the direct solver context
    231: -  type - a known type

    233:    Level: intermediate

    235: .seealso: [](sec:ds), `DSGetType()`
    236: @*/
    237: PetscErrorCode DSSetType(DS ds,DSType type)
    238: {
    239:   PetscErrorCode (*r)(DS);
    240:   PetscBool      match;

    242:   PetscFunctionBegin;
    244:   PetscAssertPointer(type,2);

    246:   PetscCall(PetscObjectTypeCompare((PetscObject)ds,type,&match));
    247:   if (match) PetscFunctionReturn(PETSC_SUCCESS);

    249:   PetscCall(PetscFunctionListFind(DSList,type,&r));
    250:   PetscCheck(r,PetscObjectComm((PetscObject)ds),PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested DS type %s",type);

    252:   PetscTryTypeMethod(ds,destroy);
    253:   PetscCall(DSReset(ds));
    254:   PetscCall(PetscMemzero(ds->ops,sizeof(struct _DSOps)));

    256:   PetscCall(PetscObjectChangeTypeName((PetscObject)ds,type));
    257:   PetscCall((*r)(ds));
    258:   PetscFunctionReturn(PETSC_SUCCESS);
    259: }

    261: /*@
    262:    DSGetType - Gets the `DS` type name (as a string) from the `DS` context.

    264:    Not Collective

    266:    Input Parameter:
    267: .  ds - the direct solver context

    269:    Output Parameter:
    270: .  type - name of the direct solver

    272:    Level: intermediate

    274: .seealso: [](sec:ds), `DSSetType()`
    275: @*/
    276: PetscErrorCode DSGetType(DS ds,DSType *type)
    277: {
    278:   PetscFunctionBegin;
    280:   PetscAssertPointer(type,2);
    281:   *type = ((PetscObject)ds)->type_name;
    282:   PetscFunctionReturn(PETSC_SUCCESS);
    283: }

    285: /*@
    286:    DSDuplicate - Creates a new direct solver object with the same options as
    287:    an existing one.

    289:    Collective

    291:    Input Parameter:
    292: .  ds - direct solver context

    294:    Output Parameter:
    295: .  dsnew - location to put the new `DS`

    297:    Notes:
    298:    `DSDuplicate()` DOES NOT COPY the matrices, and the new `DS` does not even have
    299:    internal arrays allocated. Use `DSAllocate()` to use the new `DS`.

    301:    The sorting criterion options are not copied, see `DSSetSlepcSC()`.

    303:    Level: intermediate

    305: .seealso: [](sec:ds), `DSCreate()`, `DSAllocate()`, `DSSetSlepcSC()`
    306: @*/
    307: PetscErrorCode DSDuplicate(DS ds,DS *dsnew)
    308: {
    309:   PetscFunctionBegin;
    311:   PetscAssertPointer(dsnew,2);
    312:   PetscCall(DSCreate(PetscObjectComm((PetscObject)ds),dsnew));
    313:   if (((PetscObject)ds)->type_name) PetscCall(DSSetType(*dsnew,((PetscObject)ds)->type_name));
    314:   (*dsnew)->method   = ds->method;
    315:   (*dsnew)->compact  = ds->compact;
    316:   (*dsnew)->refined  = ds->refined;
    317:   (*dsnew)->extrarow = ds->extrarow;
    318:   (*dsnew)->bs       = ds->bs;
    319:   (*dsnew)->pmode    = ds->pmode;
    320:   PetscFunctionReturn(PETSC_SUCCESS);
    321: }

    323: /*@
    324:    DSSetMethod - Selects the method to be used to solve the problem.

    326:    Logically Collective

    328:    Input Parameters:
    329: +  ds   - the direct solver context
    330: -  meth - an index identifying the method

    332:    Options Database Key:
    333: .  -ds_method \<meth\> - sets the method

    335:    Level: intermediate

    337: .seealso: [](sec:ds), `DSGetMethod()`
    338: @*/
    339: PetscErrorCode DSSetMethod(DS ds,PetscInt meth)
    340: {
    341:   PetscFunctionBegin;
    344:   PetscCheck(meth>=0,PetscObjectComm((PetscObject)ds),PETSC_ERR_ARG_OUTOFRANGE,"The method must be a non-negative integer");
    345:   PetscCheck(meth<=DS_MAX_SOLVE,PetscObjectComm((PetscObject)ds),PETSC_ERR_ARG_OUTOFRANGE,"Too large value for the method");
    346:   ds->method = meth;
    347:   PetscFunctionReturn(PETSC_SUCCESS);
    348: }

    350: /*@
    351:    DSGetMethod - Gets the method currently used in the `DS`.

    353:    Not Collective

    355:    Input Parameter:
    356: .  ds - the direct solver context

    358:    Output Parameter:
    359: .  meth - identifier of the method

    361:    Level: intermediate

    363: .seealso: [](sec:ds), `DSSetMethod()`
    364: @*/
    365: PetscErrorCode DSGetMethod(DS ds,PetscInt *meth)
    366: {
    367:   PetscFunctionBegin;
    369:   PetscAssertPointer(meth,2);
    370:   *meth = ds->method;
    371:   PetscFunctionReturn(PETSC_SUCCESS);
    372: }

    374: /*@
    375:    DSSetParallel - Selects the mode of operation in parallel runs.

    377:    Logically Collective

    379:    Input Parameters:
    380: +  ds    - the direct solver context
    381: -  pmode - the parallel mode

    383:    Options Database Key:
    384: .  -ds_parallel \<pmode\> - sets the parallel mode `redundant`,`synchronized`,`distributed`

    386:    Notes:
    387:    In the `redundant` parallel mode, all processes will make the computation
    388:    redundantly, starting from the same data, and producing the same result.
    389:    This result may be slightly different in the different processes if using a
    390:    multithreaded BLAS library, which may cause issues in ill-conditioned problems.

    392:    In the `synchronized` parallel mode, only the first MPI process performs the
    393:    computation and then the computed quantities are broadcast to the other
    394:    processes in the communicator. This communication is not done automatically,
    395:    an explicit call to `DSSynchronize()` is required.

    397:    The `distributed` parallel mode can be used in some `DS` types only, such
    398:    as the contour integral method of `DSNEP`. In this case, every MPI process
    399:    will be in charge of part of the computation.

    401:    Level: advanced

    403: .seealso: [](sec:ds), `DSSynchronize()`, `DSGetParallel()`
    404: @*/
    405: PetscErrorCode DSSetParallel(DS ds,DSParallelType pmode)
    406: {
    407:   PetscFunctionBegin;
    410:   ds->pmode = pmode;
    411:   PetscFunctionReturn(PETSC_SUCCESS);
    412: }

    414: /*@
    415:    DSGetParallel - Gets the mode of operation in parallel runs.

    417:    Not Collective

    419:    Input Parameter:
    420: .  ds - the direct solver context

    422:    Output Parameter:
    423: .  pmode - the parallel mode

    425:    Level: advanced

    427: .seealso: [](sec:ds), `DSSetParallel()`
    428: @*/
    429: PetscErrorCode DSGetParallel(DS ds,DSParallelType *pmode)
    430: {
    431:   PetscFunctionBegin;
    433:   PetscAssertPointer(pmode,2);
    434:   *pmode = ds->pmode;
    435:   PetscFunctionReturn(PETSC_SUCCESS);
    436: }

    438: /*@
    439:    DSSetCompact - Switch to compact storage of matrices.

    441:    Logically Collective

    443:    Input Parameters:
    444: +  ds   - the direct solver context
    445: -  comp - a boolean flag

    447:    Notes:
    448:    Compact storage is used in some `DS` types such as `DSHEP` when the matrix
    449:    is tridiagonal. This flag can be used to indicate whether the user
    450:    provides the matrix entries via the compact form (the tridiagonal `DS_MAT_T`)
    451:    or the non-compact one (`DS_MAT_A`).

    453:    The default is `PETSC_FALSE`.

    455:    Level: advanced

    457: .seealso: [](sec:ds), `DSGetCompact()`
    458: @*/
    459: PetscErrorCode DSSetCompact(DS ds,PetscBool comp)
    460: {
    461:   PetscFunctionBegin;
    464:   if (ds->compact != comp && ds->ld) PetscTryTypeMethod(ds,setcompact,comp);
    465:   ds->compact = comp;
    466:   PetscFunctionReturn(PETSC_SUCCESS);
    467: }

    469: /*@
    470:    DSGetCompact - Gets the compact storage flag.

    472:    Not Collective

    474:    Input Parameter:
    475: .  ds - the direct solver context

    477:    Output Parameter:
    478: .  comp - the flag

    480:    Level: advanced

    482: .seealso: [](sec:ds), `DSSetCompact()`
    483: @*/
    484: PetscErrorCode DSGetCompact(DS ds,PetscBool *comp)
    485: {
    486:   PetscFunctionBegin;
    488:   PetscAssertPointer(comp,2);
    489:   *comp = ds->compact;
    490:   PetscFunctionReturn(PETSC_SUCCESS);
    491: }

    493: /*@
    494:    DSSetExtraRow - Sets a flag to indicate that the matrix has one extra
    495:    row.

    497:    Logically Collective

    499:    Input Parameters:
    500: +  ds  - the direct solver context
    501: -  ext - a boolean flag

    503:    Notes:
    504:    In Krylov methods it is useful that the matrix representing the direct solver
    505:    has one extra row, i.e., has dimension $(n+1) \times n$. If this flag is activated, all
    506:    transformations applied to the right of the matrix also affect this additional
    507:    row. In that case, $(n+1)$ must be less or equal than the leading dimension.

    509:    The default is `PETSC_FALSE`.

    511:    Level: advanced

    513: .seealso: [](sec:ds), `DSSolve()`, `DSAllocate()`, `DSGetExtraRow()`
    514: @*/
    515: PetscErrorCode DSSetExtraRow(DS ds,PetscBool ext)
    516: {
    517:   PetscFunctionBegin;
    520:   PetscCheck(!ext || ds->n==0 || ds->n!=ds->ld,PetscObjectComm((PetscObject)ds),PETSC_ERR_ORDER,"Cannot set extra row after setting n=ld");
    521:   ds->extrarow = ext;
    522:   PetscFunctionReturn(PETSC_SUCCESS);
    523: }

    525: /*@
    526:    DSGetExtraRow - Gets the extra row flag.

    528:    Not Collective

    530:    Input Parameter:
    531: .  ds - the direct solver context

    533:    Output Parameter:
    534: .  ext - the flag

    536:    Level: advanced

    538: .seealso: [](sec:ds), `DSSetExtraRow()`
    539: @*/
    540: PetscErrorCode DSGetExtraRow(DS ds,PetscBool *ext)
    541: {
    542:   PetscFunctionBegin;
    544:   PetscAssertPointer(ext,2);
    545:   *ext = ds->extrarow;
    546:   PetscFunctionReturn(PETSC_SUCCESS);
    547: }

    549: /*@
    550:    DSSetRefined - Sets a flag to indicate that refined vectors must be
    551:    computed.

    553:    Logically Collective

    555:    Input Parameters:
    556: +  ds  - the direct solver context
    557: -  ref - a boolean flag

    559:    Notes:
    560:    Normally the vectors returned in `DS_MAT_X` are eigenvectors of the
    561:    projected matrix. With this flag activated, `DSVectors()` will return
    562:    the right singular vector of the smallest singular value of matrix
    563:    $\tilde{A}-\theta I$, where $\tilde{A}$ is the extended $(n+1)\times n$
    564:    matrix and $\theta$ is the Ritz value. This is used in the refined Ritz
    565:    approximation {cite:p}`Jia97`.

    567:    The default is `PETSC_FALSE`.

    569:    Level: advanced

    571: .seealso: [](sec:ds), `DSVectors()`, `DSGetRefined()`
    572: @*/
    573: PetscErrorCode DSSetRefined(DS ds,PetscBool ref)
    574: {
    575:   PetscFunctionBegin;
    578:   ds->refined = ref;
    579:   PetscFunctionReturn(PETSC_SUCCESS);
    580: }

    582: /*@
    583:    DSGetRefined - Gets the refined vectors flag.

    585:    Not Collective

    587:    Input Parameter:
    588: .  ds - the direct solver context

    590:    Output Parameter:
    591: .  ref - the flag

    593:    Level: advanced

    595: .seealso: [](sec:ds), `DSSetRefined()`
    596: @*/
    597: PetscErrorCode DSGetRefined(DS ds,PetscBool *ref)
    598: {
    599:   PetscFunctionBegin;
    601:   PetscAssertPointer(ref,2);
    602:   *ref = ds->refined;
    603:   PetscFunctionReturn(PETSC_SUCCESS);
    604: }

    606: /*@
    607:    DSSetBlockSize - Sets the block size.

    609:    Logically Collective

    611:    Input Parameters:
    612: +  ds - the direct solver context
    613: -  bs - the block size

    615:    Options Database Key:
    616: .  -ds_block_size \<bs\> - sets the block size

    618:    Level: intermediate

    620: .seealso: [](sec:ds), `DSGetBlockSize()`
    621: @*/
    622: PetscErrorCode DSSetBlockSize(DS ds,PetscInt bs)
    623: {
    624:   PetscFunctionBegin;
    627:   PetscCheck(bs>0,PetscObjectComm((PetscObject)ds),PETSC_ERR_ARG_OUTOFRANGE,"The block size must be at least one");
    628:   ds->bs = bs;
    629:   PetscFunctionReturn(PETSC_SUCCESS);
    630: }

    632: /*@
    633:    DSGetBlockSize - Gets the block size.

    635:    Not Collective

    637:    Input Parameter:
    638: .  ds - the direct solver context

    640:    Output Parameter:
    641: .  bs - block size

    643:    Level: intermediate

    645: .seealso: [](sec:ds), `DSSetBlockSize()`
    646: @*/
    647: PetscErrorCode DSGetBlockSize(DS ds,PetscInt *bs)
    648: {
    649:   PetscFunctionBegin;
    651:   PetscAssertPointer(bs,2);
    652:   *bs = ds->bs;
    653:   PetscFunctionReturn(PETSC_SUCCESS);
    654: }

    656: /*@C
    657:    DSSetSlepcSC - Sets the sorting criterion context.

    659:    Logically Collective

    661:    Input Parameters:
    662: +  ds - the direct solver context
    663: -  sc - a pointer to the sorting criterion context

    665:    Note:
    666:    Not available in Fortran.

    668:    Level: developer

    670: .seealso: [](sec:ds), `DSGetSlepcSC()`, `DSSort()`
    671: @*/
    672: PetscErrorCode DSSetSlepcSC(DS ds,SlepcSC sc)
    673: {
    674:   PetscFunctionBegin;
    676:   PetscAssertPointer(sc,2);
    677:   if (ds->sc && !ds->scset) PetscCall(PetscFree(ds->sc));
    678:   ds->sc    = sc;
    679:   ds->scset = PETSC_TRUE;
    680:   PetscFunctionReturn(PETSC_SUCCESS);
    681: }

    683: /*@C
    684:    DSGetSlepcSC - Gets the sorting criterion context.

    686:    Not Collective

    688:    Input Parameter:
    689: .  ds - the direct solver context

    691:    Output Parameter:
    692: .  sc - a pointer to the sorting criterion context

    694:    Note:
    695:    Not available in Fortran.

    697:    Level: developer

    699: .seealso: [](sec:ds), `DSSetSlepcSC()`, `DSSort()`
    700: @*/
    701: PetscErrorCode DSGetSlepcSC(DS ds,SlepcSC *sc)
    702: {
    703:   PetscFunctionBegin;
    705:   PetscAssertPointer(sc,2);
    706:   if (!ds->sc) PetscCall(PetscNew(&ds->sc));
    707:   *sc = ds->sc;
    708:   PetscFunctionReturn(PETSC_SUCCESS);
    709: }

    711: /*@
    712:    DSSetFromOptions - Sets `DS` options from the options database.

    714:    Collective

    716:    Input Parameter:
    717: .  ds - the direct solver context

    719:    Notes:
    720:    To see all options, run your program with the `-help` option.

    722:    Level: beginner

    724: .seealso: [](sec:ds), `DSSetOptionsPrefix()`
    725: @*/
    726: PetscErrorCode DSSetFromOptions(DS ds)
    727: {
    728:   PetscInt       bs,meth;
    729:   PetscBool      flag;
    730:   DSParallelType pmode;

    732:   PetscFunctionBegin;
    734:   PetscCall(DSRegisterAll());
    735:   /* Set default type (we do not allow changing it with -ds_type) */
    736:   if (!((PetscObject)ds)->type_name) PetscCall(DSSetType(ds,DSNHEP));
    737:   PetscObjectOptionsBegin((PetscObject)ds);

    739:     PetscCall(PetscOptionsInt("-ds_block_size","Block size for the dense system solver","DSSetBlockSize",ds->bs,&bs,&flag));
    740:     if (flag) PetscCall(DSSetBlockSize(ds,bs));

    742:     PetscCall(PetscOptionsInt("-ds_method","Method to be used for the dense system","DSSetMethod",ds->method,&meth,&flag));
    743:     if (flag) PetscCall(DSSetMethod(ds,meth));

    745:     PetscCall(PetscOptionsEnum("-ds_parallel","Operation mode in parallel runs","DSSetParallel",DSParallelTypes,(PetscEnum)ds->pmode,(PetscEnum*)&pmode,&flag));
    746:     if (flag) PetscCall(DSSetParallel(ds,pmode));

    748:     PetscTryTypeMethod(ds,setfromoptions,PetscOptionsObject);
    749:     PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)ds,PetscOptionsObject));
    750:   PetscOptionsEnd();
    751:   PetscFunctionReturn(PETSC_SUCCESS);
    752: }

    754: /*@
    755:    DSView - Prints the `DS` data structure.

    757:    Collective

    759:    Input Parameters:
    760: +  ds - the direct solver context
    761: -  viewer - optional visualization context

    763:    Notes:
    764:    The available visualization contexts include
    765: +     `PETSC_VIEWER_STDOUT_SELF` - standard output (default)
    766: -     `PETSC_VIEWER_STDOUT_WORLD` - synchronized standard output where only the
    767:          first process opens the file; all other processes send their data to the
    768:          first one to print

    770:    The user can open an alternative visualization context with `PetscViewerASCIIOpen()`
    771:    to output to a specified file.

    773:    Use `DSViewFromOptions()` to allow the user to select many different `PetscViewerType`
    774:    and formats from the options database.

    776:    Level: beginner

    778: .seealso: [](sec:ds), `DSCreate()`, `DSViewFromOptions()`, `DSViewMat()`
    779: @*/
    780: PetscErrorCode DSView(DS ds,PetscViewer viewer)
    781: {
    782:   PetscBool         isascii;
    783:   PetscViewerFormat format;
    784:   PetscMPIInt       size;

    786:   PetscFunctionBegin;
    788:   if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)ds),&viewer));
    790:   PetscCheckSameComm(ds,1,viewer,2);
    791:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii));
    792:   if (isascii) {
    793:     PetscCall(PetscViewerGetFormat(viewer,&format));
    794:     PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)ds,viewer));
    795:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)ds),&size));
    796:     if (size>1) PetscCall(PetscViewerASCIIPrintf(viewer,"  parallel operation mode: %s\n",DSParallelTypes[ds->pmode]));
    797:     if (format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
    798:       PetscCall(PetscViewerASCIIPrintf(viewer,"  current state: %s\n",DSStateTypes[ds->state]));
    799:       PetscCall(PetscViewerASCIIPrintf(viewer,"  dimensions: ld=%" PetscInt_FMT ", n=%" PetscInt_FMT ", l=%" PetscInt_FMT ", k=%" PetscInt_FMT,ds->ld,ds->n,ds->l,ds->k));
    800:       if (ds->state==DS_STATE_TRUNCATED) PetscCall(PetscViewerASCIIPrintf(viewer,", t=%" PetscInt_FMT "\n",ds->t));
    801:       else PetscCall(PetscViewerASCIIPrintf(viewer,"\n"));
    802:       PetscCall(PetscViewerASCIIPrintf(viewer,"  flags:%s%s%s\n",ds->compact?" compact":"",ds->extrarow?" extrarow":"",ds->refined?" refined":""));
    803:     }
    804:     PetscCall(PetscViewerASCIIPushTab(viewer));
    805:     PetscTryTypeMethod(ds,view,viewer);
    806:     PetscCall(PetscViewerASCIIPopTab(viewer));
    807:   }
    808:   PetscFunctionReturn(PETSC_SUCCESS);
    809: }

    811: /*@
    812:    DSViewFromOptions - View (print) a `DS` object based on values in the options database.

    814:    Collective

    816:    Input Parameters:
    817: +  ds   - the direct solver context
    818: .  obj  - optional object that provides the options prefix used to query the options database
    819: -  name - command line option

    821:    Level: intermediate

    823: .seealso: [](sec:ds), `DSView()`, `DSCreate()`, `PetscObjectViewFromOptions()`
    824: @*/
    825: PetscErrorCode DSViewFromOptions(DS ds,PetscObject obj,const char name[])
    826: {
    827:   PetscFunctionBegin;
    829:   PetscCall(PetscObjectViewFromOptions((PetscObject)ds,obj,name));
    830:   PetscFunctionReturn(PETSC_SUCCESS);
    831: }

    833: /*@
    834:    DSAllocate - Allocates memory for internal storage or matrices in `DS`.

    836:    Logically Collective

    838:    Input Parameters:
    839: +  ds - the direct solver context
    840: -  ld - leading dimension (maximum allowed dimension for the matrices, including
    841:         the extra row if present)

    843:    Note:
    844:    If the leading dimension is different from a previously set value, then
    845:    all matrices are destroyed with `DSReset()`.

    847:    Level: intermediate

    849: .seealso: [](sec:ds), `DSGetLeadingDimension()`, `DSSetDimensions()`, `DSSetExtraRow()`, `DSReset()`, `DSReallocate()`
    850: @*/
    851: PetscErrorCode DSAllocate(DS ds,PetscInt ld)
    852: {
    853:   PetscFunctionBegin;
    857:   PetscCheck(ld>0,PetscObjectComm((PetscObject)ds),PETSC_ERR_ARG_OUTOFRANGE,"Leading dimension should be at least one");
    858:   if (ld!=ds->ld) {
    859:     PetscCall(PetscInfo(ds,"Allocating memory with leading dimension=%" PetscInt_FMT "\n",ld));
    860:     PetscCall(DSReset(ds));
    861:     ds->ld = ld;
    862:     PetscUseTypeMethod(ds,allocate,ld);
    863:   }
    864:   PetscFunctionReturn(PETSC_SUCCESS);
    865: }

    867: /*@
    868:    DSReallocate - Reallocates memory for internal storage or matrices in `DS`,
    869:    keeping the previously set data.

    871:    Logically Collective

    873:    Input Parameters:
    874: +  ds - the direct solver context
    875: -  ld - new leading dimension

    877:    Notes:
    878:    The new leading dimension must be larger than the previous one. The relevant
    879:    data previously set is copied over to the new data structures.

    881:    This operation is not available in all `DS` types.

    883:    Level: developer

    885: .seealso: [](sec:ds), `DSAllocate()`
    886: @*/
    887: PetscErrorCode DSReallocate(DS ds,PetscInt ld)
    888: {
    889:   PetscFunctionBegin;
    893:   PetscCheck(ds->ld,PetscObjectComm((PetscObject)ds),PETSC_ERR_ORDER,"DSAllocate() must be called first");
    894:   PetscCheck(ld>ds->ld,PetscObjectComm((PetscObject)ds),PETSC_ERR_ARG_OUTOFRANGE,"New leading dimension %" PetscInt_FMT " must be larger than the previous one %" PetscInt_FMT,ld,ds->ld);
    895:   PetscCall(PetscInfo(ds,"Reallocating memory with new leading dimension=%" PetscInt_FMT "\n",ld));
    896:   PetscUseTypeMethod(ds,reallocate,ld);
    897:   ds->ld = ld;
    898:   PetscFunctionReturn(PETSC_SUCCESS);
    899: }

    901: /*@
    902:    DSReset - Resets the `DS` context to the initial state.

    904:    Collective

    906:    Input Parameter:
    907: .  ds - the direct solver context

    909:    Note:
    910:    All data structures with size depending on the leading dimension
    911:    of `DSAllocate()` are released.

    913:    Level: advanced

    915: .seealso: [](sec:ds), `DSDestroy()`, `DSAllocate()`
    916: @*/
    917: PetscErrorCode DSReset(DS ds)
    918: {
    919:   PetscInt       i;

    921:   PetscFunctionBegin;
    923:   if (!ds) PetscFunctionReturn(PETSC_SUCCESS);
    924:   ds->state    = DS_STATE_RAW;
    925:   ds->ld       = 0;
    926:   ds->l        = 0;
    927:   ds->n        = 0;
    928:   ds->k        = 0;
    929:   for (i=0;i<DS_NUM_MAT;i++) PetscCall(MatDestroy(&ds->omat[i]));
    930:   PetscCall(PetscFree(ds->perm));
    931:   PetscFunctionReturn(PETSC_SUCCESS);
    932: }

    934: /*@
    935:    DSDestroy - Destroys `DS` context that was created with `DSCreate()`.

    937:    Collective

    939:    Input Parameter:
    940: .  ds - the direct solver context

    942:    Level: beginner

    944: .seealso: [](sec:ds), `DSCreate()`
    945: @*/
    946: PetscErrorCode DSDestroy(DS *ds)
    947: {
    948:   PetscFunctionBegin;
    949:   if (!*ds) PetscFunctionReturn(PETSC_SUCCESS);
    951:   if (--((PetscObject)*ds)->refct > 0) { *ds = NULL; PetscFunctionReturn(PETSC_SUCCESS); }
    952:   PetscCall(DSReset(*ds));
    953:   PetscTryTypeMethod(*ds,destroy);
    954:   PetscCall(PetscFree((*ds)->work));
    955:   PetscCall(PetscFree((*ds)->rwork));
    956:   PetscCall(PetscFree((*ds)->iwork));
    957:   if (!(*ds)->scset) PetscCall(PetscFree((*ds)->sc));
    958:   PetscCall(PetscHeaderDestroy(ds));
    959:   PetscFunctionReturn(PETSC_SUCCESS);
    960: }

    962: /*@C
    963:    DSRegister - Adds a direct solver to the `DS` package.

    965:    Not Collective

    967:    Input Parameters:
    968: +  name - name of a new user-defined `DS`
    969: -  function - routine to create context

    971:    Note:
    972:    `DSRegister()` may be called multiple times to add several user-defined
    973:    direct solvers.

    975:    Level: advanced

    977: .seealso: [](sec:ds), `DSRegisterAll()`
    978: @*/
    979: PetscErrorCode DSRegister(const char *name,PetscErrorCode (*function)(DS))
    980: {
    981:   PetscFunctionBegin;
    982:   PetscCall(DSInitializePackage());
    983:   PetscCall(PetscFunctionListAdd(&DSList,name,function));
    984:   PetscFunctionReturn(PETSC_SUCCESS);
    985: }

    987: SLEPC_EXTERN PetscErrorCode DSCreate_HEP(DS);
    988: SLEPC_EXTERN PetscErrorCode DSCreate_NHEP(DS);
    989: SLEPC_EXTERN PetscErrorCode DSCreate_GHEP(DS);
    990: SLEPC_EXTERN PetscErrorCode DSCreate_GHIEP(DS);
    991: SLEPC_EXTERN PetscErrorCode DSCreate_GNHEP(DS);
    992: SLEPC_EXTERN PetscErrorCode DSCreate_NHEPTS(DS);
    993: SLEPC_EXTERN PetscErrorCode DSCreate_SVD(DS);
    994: SLEPC_EXTERN PetscErrorCode DSCreate_HSVD(DS);
    995: SLEPC_EXTERN PetscErrorCode DSCreate_GSVD(DS);
    996: SLEPC_EXTERN PetscErrorCode DSCreate_PEP(DS);
    997: SLEPC_EXTERN PetscErrorCode DSCreate_NEP(DS);

    999: /*@C
    1000:    DSRegisterAll - Registers all of the direct solvers in the `DS` package.

    1002:    Not Collective

    1004:    Level: advanced

    1006: .seealso: [](sec:ds), `DSRegister()`
    1007: @*/
    1008: PetscErrorCode DSRegisterAll(void)
    1009: {
    1010:   PetscFunctionBegin;
    1011:   if (DSRegisterAllCalled) PetscFunctionReturn(PETSC_SUCCESS);
    1012:   DSRegisterAllCalled = PETSC_TRUE;
    1013:   PetscCall(DSRegister(DSHEP,DSCreate_HEP));
    1014:   PetscCall(DSRegister(DSNHEP,DSCreate_NHEP));
    1015:   PetscCall(DSRegister(DSGHEP,DSCreate_GHEP));
    1016:   PetscCall(DSRegister(DSGHIEP,DSCreate_GHIEP));
    1017:   PetscCall(DSRegister(DSGNHEP,DSCreate_GNHEP));
    1018:   PetscCall(DSRegister(DSNHEPTS,DSCreate_NHEPTS));
    1019:   PetscCall(DSRegister(DSSVD,DSCreate_SVD));
    1020:   PetscCall(DSRegister(DSHSVD,DSCreate_HSVD));
    1021:   PetscCall(DSRegister(DSGSVD,DSCreate_GSVD));
    1022:   PetscCall(DSRegister(DSPEP,DSCreate_PEP));
    1023:   PetscCall(DSRegister(DSNEP,DSCreate_NEP));
    1024:   PetscFunctionReturn(PETSC_SUCCESS);
    1025: }