Date: 2021-02-01T14:41:46+00:00

Actual source code: bvbasic.c
slepc-3.14.2 2021-02-01
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2020, 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 BV routines
     12: */

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

     16: PetscBool         BVRegisterAllCalled = PETSC_FALSE;
     17: PetscFunctionList BVList = 0;

     19: /*@C
     20:    BVSetType - Selects the type for the BV object.

     22:    Logically Collective on bv

     24:    Input Parameter:
     25: +  bv   - the basis vectors context
     26: -  type - a known type

     28:    Options Database Key:
     29: .  -bv_type <type> - Sets BV type

     31:    Level: intermediate

     33: .seealso: BVGetType()
     34: @*/
     35: PetscErrorCode BVSetType(BV bv,BVType type)
     36: {
     37:   PetscErrorCode ierr,(*r)(BV);
     38:   PetscBool      match;

     44:   PetscObjectTypeCompare((PetscObject)bv,type,&match);
     45:   if (match) return(0);
     46:   PetscStrcmp(type,BVTENSOR,&match);
     47:   if (match) SETERRQ(PetscObjectComm((PetscObject)bv),1,"Use BVCreateTensor() to create a BV of type tensor");

     49:    PetscFunctionListFind(BVList,type,&r);
     50:   if (!r) SETERRQ1(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_UNKNOWN_TYPE,"Unable to find requested BV type %s",type);

     52:   if (bv->ops->destroy) { (*bv->ops->destroy)(bv); }
     53:   PetscMemzero(bv->ops,sizeof(struct _BVOps));

     55:   PetscObjectChangeTypeName((PetscObject)bv,type);
     56:   if (bv->n < 0 && bv->N < 0) {
     57:     bv->ops->create = r;
     58:   } else {
     59:     PetscLogEventBegin(BV_Create,bv,0,0,0);
     60:     (*r)(bv);
     61:     PetscLogEventEnd(BV_Create,bv,0,0,0);
     62:   }
     63:   return(0);
     64: }

     66: /*@C
     67:    BVGetType - Gets the BV type name (as a string) from the BV context.

     69:    Not Collective

     71:    Input Parameter:
     72: .  bv - the basis vectors context

     74:    Output Parameter:
     75: .  name - name of the type of basis vectors

     77:    Level: intermediate

     79: .seealso: BVSetType()
     80: @*/
     81: PetscErrorCode BVGetType(BV bv,BVType *type)
     82: {
     86:   *type = ((PetscObject)bv)->type_name;
     87:   return(0);
     88: }

     90: /*@
     91:    BVSetSizes - Sets the local and global sizes, and the number of columns.

     93:    Collective on bv

     95:    Input Parameters:
     96: +  bv - the basis vectors
     97: .  n  - the local size (or PETSC_DECIDE to have it set)
     98: .  N  - the global size (or PETSC_DECIDE)
     99: -  m  - the number of columns

    101:    Notes:
    102:    n and N cannot be both PETSC_DECIDE.
    103:    If one processor calls this with N of PETSC_DECIDE then all processors must,
    104:    otherwise the program will hang.

    106:    Level: beginner

    108: .seealso: BVSetSizesFromVec(), BVGetSizes(), BVResize()
    109: @*/
    110: PetscErrorCode BVSetSizes(BV bv,PetscInt n,PetscInt N,PetscInt m)
    111: {
    113:   PetscInt       ma;

    119:   if (N >= 0 && n > N) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Local size %D cannot be larger than global size %D",n,N);
    120:   if (m <= 0) SETERRQ1(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Number of columns %D must be positive",m);
    121:   if ((bv->n >= 0 || bv->N >= 0) && (bv->n != n || bv->N != N)) SETERRQ4(PetscObjectComm((PetscObject)bv),PETSC_ERR_SUP,"Cannot change/reset vector sizes to %D local %D global after previously setting them to %D local %D global",n,N,bv->n,bv->N);
    122:   if (bv->m > 0 && bv->m != m) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_SUP,"Cannot change the number of columns to %D after previously setting it to %D; use BVResize()",m,bv->m);
    123:   bv->n = n;
    124:   bv->N = N;
    125:   bv->m = m;
    126:   bv->k = m;
    127:   if (!bv->t) {  /* create template vector and get actual dimensions */
    128:     VecCreate(PetscObjectComm((PetscObject)bv),&bv->t);
    129:     VecSetSizes(bv->t,bv->n,bv->N);
    130:     VecSetFromOptions(bv->t);
    131:     VecGetSize(bv->t,&bv->N);
    132:     VecGetLocalSize(bv->t,&bv->n);
    133:     if (bv->matrix) {  /* check compatible dimensions of user-provided matrix */
    134:       MatGetLocalSize(bv->matrix,&ma,NULL);
    135:       if (bv->n!=ma) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Local dimension %D does not match that of matrix given at BVSetMatrix %D",bv->n,ma);
    136:     }
    137:   }
    138:   if (bv->ops->create) {
    139:     PetscLogEventBegin(BV_Create,bv,0,0,0);
    140:     (*bv->ops->create)(bv);
    141:     PetscLogEventEnd(BV_Create,bv,0,0,0);
    142:     bv->ops->create = 0;
    143:     bv->defersfo = PETSC_FALSE;
    144:   }
    145:   return(0);
    146: }

    148: /*@
    149:    BVSetSizesFromVec - Sets the local and global sizes, and the number of columns.
    150:    Local and global sizes are specified indirectly by passing a template vector.

    152:    Collective on bv

    154:    Input Parameters:
    155: +  bv - the basis vectors
    156: .  t  - the template vector
    157: -  m  - the number of columns

    159:    Level: beginner

    161: .seealso: BVSetSizes(), BVGetSizes(), BVResize()
    162: @*/
    163: PetscErrorCode BVSetSizesFromVec(BV bv,Vec t,PetscInt m)
    164: {
    166:   PetscInt       ma;

    173:   if (m <= 0) SETERRQ1(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Number of columns %D must be positive",m);
    174:   if (bv->t) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_SUP,"Template vector was already set by a previous call to BVSetSizes/FromVec");
    175:   VecGetSize(t,&bv->N);
    176:   VecGetLocalSize(t,&bv->n);
    177:   if (bv->matrix) {  /* check compatible dimensions of user-provided matrix */
    178:     MatGetLocalSize(bv->matrix,&ma,NULL);
    179:     if (bv->n!=ma) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Local dimension %D does not match that of matrix given at BVSetMatrix %D",bv->n,ma);
    180:   }
    181:   bv->m = m;
    182:   bv->k = m;
    183:   bv->t = t;
    184:   PetscObjectReference((PetscObject)t);
    185:   if (bv->ops->create) {
    186:     (*bv->ops->create)(bv);
    187:     bv->ops->create = 0;
    188:     bv->defersfo = PETSC_FALSE;
    189:   }
    190:   return(0);
    191: }

    193: /*@
    194:    BVGetSizes - Returns the local and global sizes, and the number of columns.

    196:    Not Collective

    198:    Input Parameter:
    199: .  bv - the basis vectors

    201:    Output Parameters:
    202: +  n  - the local size
    203: .  N  - the global size
    204: -  m  - the number of columns

    206:    Note:
    207:    Normal usage requires that bv has already been given its sizes, otherwise
    208:    the call fails. However, this function can also be used to determine if
    209:    a BV object has been initialized completely (sizes and type). For this,
    210:    call with n=NULL and N=NULL, then a return value of m=0 indicates that
    211:    the BV object is not ready for use yet.

    213:    Level: beginner

    215: .seealso: BVSetSizes(), BVSetSizesFromVec()
    216: @*/
    217: PetscErrorCode BVGetSizes(BV bv,PetscInt *n,PetscInt *N,PetscInt *m)
    218: {
    220:   if (!bv) {
    221:     if (m && !n && !N) *m = 0;
    222:     return(0);
    223:   }
    225:   if (n || N) BVCheckSizes(bv,1);
    226:   if (n) *n = bv->n;
    227:   if (N) *N = bv->N;
    228:   if (m) *m = bv->m;
    229:   if (m && !n && !N && !((PetscObject)bv)->type_name) *m = 0;
    230:   return(0);
    231: }

    233: /*@
    234:    BVSetNumConstraints - Set the number of constraints.

    236:    Logically Collective on V

    238:    Input Parameters:
    239: +  V  - basis vectors
    240: -  nc - number of constraints

    242:    Notes:
    243:    This function sets the number of constraints to nc and marks all remaining
    244:    columns as regular. Normal user would call BVInsertConstraints() instead.

    246:    If nc is smaller than the previously set value, then some of the constraints
    247:    are discarded. In particular, using nc=0 removes all constraints preserving
    248:    the content of regular columns.

    250:    Level: developer

    252: .seealso: BVInsertConstraints()
    253: @*/
    254: PetscErrorCode BVSetNumConstraints(BV V,PetscInt nc)
    255: {
    257:   PetscInt       total,diff,i;
    258:   Vec            x,y;

    263:   if (nc<0) SETERRQ1(PetscObjectComm((PetscObject)V),PETSC_ERR_ARG_OUTOFRANGE,"Number of constraints (given %D) cannot be negative",nc);
    265:   BVCheckSizes(V,1);
    266:   if (V->ci[0]!=-V->nc-1 || V->ci[1]!=-V->nc-1) SETERRQ(PetscObjectComm((PetscObject)V),PETSC_ERR_SUP,"Cannot call BVSetNumConstraints after BVGetColumn");

    268:   diff = nc-V->nc;
    269:   if (!diff) return(0);
    270:   total = V->nc+V->m;
    271:   if (total-nc<=0) SETERRQ(PetscObjectComm((PetscObject)V),PETSC_ERR_ARG_OUTOFRANGE,"Not enough columns for the given nc value");
    272:   if (diff<0) {  /* lessen constraints, shift contents of BV */
    273:     for (i=0;i<V->m;i++) {
    274:       BVGetColumn(V,i,&x);
    275:       BVGetColumn(V,i+diff,&y);
    276:       VecCopy(x,y);
    277:       BVRestoreColumn(V,i,&x);
    278:       BVRestoreColumn(V,i+diff,&y);
    279:     }
    280:   }
    281:   V->nc = nc;
    282:   V->ci[0] = -V->nc-1;
    283:   V->ci[1] = -V->nc-1;
    284:   V->m = total-nc;
    285:   V->l = PetscMin(V->l,V->m);
    286:   V->k = PetscMin(V->k,V->m);
    287:   PetscObjectStateIncrease((PetscObject)V);
    288:   return(0);
    289: }

    291: /*@
    292:    BVGetNumConstraints - Returns the number of constraints.

    294:    Not Collective

    296:    Input Parameter:
    297: .  bv - the basis vectors

    299:    Output Parameters:
    300: .  nc - the number of constraints

    302:    Level: advanced

    304: .seealso: BVGetSizes(), BVInsertConstraints()
    305: @*/
    306: PetscErrorCode BVGetNumConstraints(BV bv,PetscInt *nc)
    307: {
    311:   *nc = bv->nc;
    312:   return(0);
    313: }

    315: /*@
    316:    BVResize - Change the number of columns.

    318:    Collective on bv

    320:    Input Parameters:
    321: +  bv   - the basis vectors
    322: .  m    - the new number of columns
    323: -  copy - a flag indicating whether current values should be kept

    325:    Note:
    326:    Internal storage is reallocated. If the copy flag is set to true, then
    327:    the contents are copied to the leading part of the new space.

    329:    Level: advanced

    331: .seealso: BVSetSizes(), BVSetSizesFromVec()
    332: @*/
    333: PetscErrorCode BVResize(BV bv,PetscInt m,PetscBool copy)
    334: {
    335:   PetscErrorCode    ierr;
    336:   PetscScalar       *array;
    337:   const PetscScalar *omega;
    338:   Vec               v;

    345:   if (m <= 0) SETERRQ1(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Number of columns %D must be positive",m);
    346:   if (bv->nc && !bv->issplit) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Cannot resize a BV with constraints");
    347:   if (bv->m == m) return(0);
    348:   BVCheckOp(bv,1,resize);

    350:   PetscLogEventBegin(BV_Create,bv,0,0,0);
    351:   (*bv->ops->resize)(bv,m,copy);
    352:   VecDestroy(&bv->buffer);
    353:   BVDestroy(&bv->cached);
    354:   PetscFree2(bv->h,bv->c);
    355:   if (bv->omega) {
    356:     if (bv->cuda) {
    357: #if defined(PETSC_HAVE_CUDA)
    358:       VecCreateSeqCUDA(PETSC_COMM_SELF,m,&v);
    359: #else
    360:       SETERRQ(PetscObjectComm((PetscObject)bv),1,"Something wrong happened");
    361: #endif
    362:     } else {
    363:       VecCreateSeq(PETSC_COMM_SELF,m,&v);
    364:     }
    365:     PetscLogObjectParent((PetscObject)bv,(PetscObject)v);
    366:     if (copy) {
    367:       VecGetArray(v,&array);
    368:       VecGetArrayRead(bv->omega,&omega);
    369:       PetscArraycpy(array,omega,PetscMin(m,bv->m));
    370:       VecRestoreArrayRead(bv->omega,&omega);
    371:       VecRestoreArray(v,&array);
    372:     } else {
    373:       VecSet(v,1.0);
    374:     }
    375:     VecDestroy(&bv->omega);
    376:     bv->omega = v;
    377:   }
    378:   bv->m = m;
    379:   bv->k = PetscMin(bv->k,m);
    380:   bv->l = PetscMin(bv->l,m);
    381:   PetscLogEventEnd(BV_Create,bv,0,0,0);
    382:   PetscObjectStateIncrease((PetscObject)bv);
    383:   return(0);
    384: }

    386: /*@
    387:    BVSetActiveColumns - Specify the columns that will be involved in operations.

    389:    Logically Collective on bv

    391:    Input Parameters:
    392: +  bv - the basis vectors context
    393: .  l  - number of leading columns
    394: -  k  - number of active columns

    396:    Notes:
    397:    In operations such as BVMult() or BVDot(), only the first k columns are
    398:    considered. This is useful when the BV is filled from left to right, so
    399:    the last m-k columns do not have relevant information.

    401:    Also in operations such as BVMult() or BVDot(), the first l columns are
    402:    normally not included in the computation. See the manpage of each
    403:    operation.

    405:    In orthogonalization operations, the first l columns are treated
    406:    differently: they participate in the orthogonalization but the computed
    407:    coefficients are not stored.

    409:    Level: intermediate

    411: .seealso: BVGetActiveColumns(), BVSetSizes()
    412: @*/
    413: PetscErrorCode BVSetActiveColumns(BV bv,PetscInt l,PetscInt k)
    414: {
    419:   BVCheckSizes(bv,1);
    420:   if (k==PETSC_DECIDE || k==PETSC_DEFAULT) {
    421:     bv->k = bv->m;
    422:   } else {
    423:     if (k<0 || k>bv->m) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of k. Must be between 0 and m");
    424:     bv->k = k;
    425:   }
    426:   if (l==PETSC_DECIDE || l==PETSC_DEFAULT) {
    427:     bv->l = 0;
    428:   } else {
    429:     if (l<0 || l>bv->k) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of l. Must be between 0 and k");
    430:     bv->l = l;
    431:   }
    432:   return(0);
    433: }

    435: /*@
    436:    BVGetActiveColumns - Returns the current active dimensions.

    438:    Not Collective

    440:    Input Parameter:
    441: .  bv - the basis vectors context

    443:    Output Parameter:
    444: +  l  - number of leading columns
    445: -  k  - number of active columns

    447:    Level: intermediate

    449: .seealso: BVSetActiveColumns()
    450: @*/
    451: PetscErrorCode BVGetActiveColumns(BV bv,PetscInt *l,PetscInt *k)
    452: {
    455:   if (l) *l = bv->l;
    456:   if (k) *k = bv->k;
    457:   return(0);
    458: }

    460: /*@
    461:    BVSetMatrix - Specifies the inner product to be used in orthogonalization.

    463:    Collective on bv

    465:    Input Parameters:
    466: +  bv    - the basis vectors context
    467: .  B     - a symmetric matrix (may be NULL)
    468: -  indef - a flag indicating if the matrix is indefinite

    470:    Notes:
    471:    This is used to specify a non-standard inner product, whose matrix
    472:    representation is given by B. Then, all inner products required during
    473:    orthogonalization are computed as (x,y)_B=y^H*B*x rather than the
    474:    standard form (x,y)=y^H*x.

    476:    Matrix B must be real symmetric (or complex Hermitian). A genuine inner
    477:    product requires that B is also positive (semi-)definite. However, we
    478:    also allow for an indefinite B (setting indef=PETSC_TRUE), in which
    479:    case the orthogonalization uses an indefinite inner product.

    481:    This affects operations BVDot(), BVNorm(), BVOrthogonalize(), and variants.

    483:    Setting B=NULL has the same effect as if the identity matrix was passed.

    485:    Level: advanced

    487: .seealso: BVGetMatrix(), BVDot(), BVNorm(), BVOrthogonalize()
    488: @*/
    489: PetscErrorCode BVSetMatrix(BV bv,Mat B,PetscBool indef)
    490: {
    492:   PetscInt       m,n;

    497:   if (B!=bv->matrix || (B && ((PetscObject)B)->id!=((PetscObject)bv->matrix)->id) || indef!=bv->indef) {
    498:     if (B) {
    500:       MatGetLocalSize(B,&m,&n);
    501:       if (m!=n) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_SIZ,"Matrix must be square");
    502:       if (bv->m && bv->n!=n) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Mismatching local dimension BV %D, Mat %D",bv->n,n);
    503:     }
    504:     if (B) { PetscObjectReference((PetscObject)B); }
    505:     MatDestroy(&bv->matrix);
    506:     bv->matrix = B;
    507:     bv->indef  = indef;
    508:     PetscObjectStateIncrease((PetscObject)bv);
    509:     if (bv->Bx) { PetscObjectStateIncrease((PetscObject)bv->Bx); }
    510:     if (bv->cached) { PetscObjectStateIncrease((PetscObject)bv->cached); }
    511:   }
    512:   return(0);
    513: }

    515: /*@
    516:    BVGetMatrix - Retrieves the matrix representation of the inner product.

    518:    Not collective, though a parallel Mat may be returned

    520:    Input Parameter:
    521: .  bv    - the basis vectors context

    523:    Output Parameter:
    524: +  B     - the matrix of the inner product (may be NULL)
    525: -  indef - the flag indicating if the matrix is indefinite

    527:    Level: advanced

    529: .seealso: BVSetMatrix()
    530: @*/
    531: PetscErrorCode BVGetMatrix(BV bv,Mat *B,PetscBool *indef)
    532: {
    535:   if (B)     *B     = bv->matrix;
    536:   if (indef) *indef = bv->indef;
    537:   return(0);
    538: }

    540: /*@
    541:    BVApplyMatrix - Multiplies a vector by the matrix representation of the
    542:    inner product.

    544:    Neighbor-wise Collective on bv

    546:    Input Parameter:
    547: +  bv - the basis vectors context
    548: -  x  - the vector

    550:    Output Parameter:
    551: .  y  - the result

    553:    Note:
    554:    If no matrix was specified this function copies the vector.

    556:    Level: advanced

    558: .seealso: BVSetMatrix(), BVApplyMatrixBV()
    559: @*/
    560: PetscErrorCode BVApplyMatrix(BV bv,Vec x,Vec y)
    561: {

    568:   if (bv->matrix) {
    569:     BV_IPMatMult(bv,x);
    570:     VecCopy(bv->Bx,y);
    571:   } else {
    572:     VecCopy(x,y);
    573:   }
    574:   return(0);
    575: }

    577: /*@
    578:    BVApplyMatrixBV - Multiplies the BV vectors by the matrix representation
    579:    of the inner product.

    581:    Neighbor-wise Collective on X

    583:    Input Parameter:
    584: .  X - the basis vectors context

    586:    Output Parameter:
    587: .  Y - the basis vectors to store the result (optional)

    589:    Note:
    590:    This function computes Y = B*X, where B is the matrix given with
    591:    BVSetMatrix(). This operation is computed as in BVMatMult().
    592:    If no matrix was specified, then it just copies Y = X.

    594:    If no Y is given, the result is stored internally in the cached BV.

    596:    Level: developer

    598: .seealso: BVSetMatrix(), BVApplyMatrix(), BVMatMult(), BVGetCachedBV()
    599: @*/
    600: PetscErrorCode BVApplyMatrixBV(BV X,BV Y)
    601: {

    606:   if (Y) {
    608:     if (X->matrix) {
    609:       BVMatMult(X,X->matrix,Y);
    610:     } else {
    611:       BVCopy(X,Y);
    612:     }
    613:   } else {
    614:     BV_IPMatMultBV(X);
    615:   }
    616:   return(0);
    617: }

    619: /*@
    620:    BVSetSignature - Sets the signature matrix to be used in orthogonalization.

    622:    Logically Collective on bv

    624:    Input Parameter:
    625: +  bv    - the basis vectors context
    626: -  omega - a vector representing the diagonal of the signature matrix

    628:    Note:
    629:    The signature matrix Omega = V'*B*V is relevant only for an indefinite B.

    631:    Level: developer

    633: .seealso: BVSetMatrix(), BVGetSignature()
    634: @*/
    635: PetscErrorCode BVSetSignature(BV bv,Vec omega)
    636: {
    637:   PetscErrorCode    ierr;
    638:   PetscInt          i,n;
    639:   const PetscScalar *pomega;
    640:   PetscScalar       *intern;

    644:   BVCheckSizes(bv,1);

    648:   VecGetSize(omega,&n);
    649:   if (n!=bv->k) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_SIZ,"Vec argument has %D elements, should be %D",n,bv->k);
    650:   BV_AllocateSignature(bv);
    651:   if (bv->indef) {
    652:     VecGetArrayRead(omega,&pomega);
    653:     VecGetArray(bv->omega,&intern);
    654:     for (i=0;i<n;i++) intern[bv->nc+i] = pomega[i];
    655:     VecRestoreArray(bv->omega,&intern);
    656:     VecRestoreArrayRead(omega,&pomega);
    657:   } else {
    658:     PetscInfo(bv,"Ignoring signature because BV is not indefinite\n");
    659:   }
    660:   PetscObjectStateIncrease((PetscObject)bv);
    661:   return(0);
    662: }

    664: /*@
    665:    BVGetSignature - Retrieves the signature matrix from last orthogonalization.

    667:    Not collective

    669:    Input Parameter:
    670: .  bv    - the basis vectors context

    672:    Output Parameter:
    673: .  omega - a vector representing the diagonal of the signature matrix

    675:    Note:
    676:    The signature matrix Omega = V'*B*V is relevant only for an indefinite B.

    678:    Level: developer

    680: .seealso: BVSetMatrix(), BVSetSignature()
    681: @*/
    682: PetscErrorCode BVGetSignature(BV bv,Vec omega)
    683: {
    684:   PetscErrorCode    ierr;
    685:   PetscInt          i,n;
    686:   PetscScalar       *pomega;
    687:   const PetscScalar *intern;

    691:   BVCheckSizes(bv,1);

    695:   VecGetSize(omega,&n);
    696:   if (n!=bv->k) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_SIZ,"Vec argument has %D elements, should be %D",n,bv->k);
    697:   if (bv->indef && bv->omega) {
    698:     VecGetArray(omega,&pomega);
    699:     VecGetArrayRead(bv->omega,&intern);
    700:     for (i=0;i<n;i++) pomega[i] = intern[bv->nc+i];
    701:     VecRestoreArrayRead(bv->omega,&intern);
    702:     VecRestoreArray(omega,&pomega);
    703:   } else {
    704:     VecSet(omega,1.0);
    705:   }
    706:   return(0);
    707: }

    709: /*@
    710:    BVSetBufferVec - Attach a vector object to be used as buffer space for
    711:    several operations.

    713:    Collective on bv

    715:    Input Parameters:
    716: +  bv     - the basis vectors context)
    717: -  buffer - the vector

    719:    Notes:
    720:    Use BVGetBufferVec() to retrieve the vector (for example, to free it
    721:    at the end of the computations).

    723:    The vector must be sequential of length (nc+m)*m, where m is the number
    724:    of columns of bv and nc is the number of constraints.

    726:    Level: developer

    728: .seealso: BVGetBufferVec(), BVSetSizes(), BVGetNumConstraints()
    729: @*/
    730: PetscErrorCode BVSetBufferVec(BV bv,Vec buffer)
    731: {
    733:   PetscInt       ld,n;
    734:   PetscMPIInt    size;

    739:   BVCheckSizes(bv,1);
    740:   VecGetSize(buffer,&n);
    741:   ld = bv->m+bv->nc;
    742:   if (n != ld*bv->m) SETERRQ1(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_SIZ,"Buffer size must be %d",ld*bv->m);
    743:   MPI_Comm_size(PetscObjectComm((PetscObject)buffer),&size);
    744:   if (size>1) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Buffer must be a sequential vector");

    746:   PetscObjectReference((PetscObject)buffer);
    747:   VecDestroy(&bv->buffer);
    748:   bv->buffer = buffer;
    749:   PetscLogObjectParent((PetscObject)bv,(PetscObject)bv->buffer);
    750:   return(0);
    751: }

    753: /*@
    754:    BVGetBufferVec - Obtain the buffer vector associated with the BV object.

    756:    Not Collective, but Vec returned is parallel if BV is parallel

    758:    Input Parameters:
    759: .  bv - the basis vectors context

    761:    Output Parameter:
    762: .  buffer - vector

    764:    Notes:
    765:    The vector is created if not available previously. It is a sequential vector
    766:    of length (nc+m)*m, where m is the number of columns of bv and nc is the number
    767:    of constraints.

    769:    Developer Notes:
    770:    The buffer vector is viewed as a column-major matrix with leading dimension
    771:    ld=nc+m, and m columns at most. In the most common usage, it has the structure
    772: .vb
    773:       | | C |
    774:       |s|---|
    775:       | | H |
    776: .ve
    777:    where H is an upper Hessenberg matrix of order m x (m-1), C contains coefficients
    778:    related to orthogonalization against constraints (first nc rows), and s is the
    779:    first column that contains scratch values computed during Gram-Schmidt
    780:    orthogonalization. In particular, BVDotColumn() and BVMultColumn() use s to
    781:    store the coefficients.

    783:    Level: developer

    785: .seealso: BVSetBufferVec(), BVSetSizes(), BVGetNumConstraints(), BVDotColumn(), BVMultColumn()
    786: @*/
    787: PetscErrorCode BVGetBufferVec(BV bv,Vec *buffer)
    788: {
    790:   PetscInt       ld;

    795:   BVCheckSizes(bv,1);
    796:   if (!bv->buffer) {
    797:     ld = bv->m+bv->nc;
    798:     VecCreate(PETSC_COMM_SELF,&bv->buffer);
    799:     VecSetSizes(bv->buffer,PETSC_DECIDE,ld*bv->m);
    800:     VecSetType(bv->buffer,((PetscObject)bv->t)->type_name);
    801:     PetscLogObjectParent((PetscObject)bv,(PetscObject)bv->buffer);
    802:   }
    803:   *buffer = bv->buffer;
    804:   return(0);
    805: }

    807: /*@
    808:    BVSetRandomContext - Sets the PetscRandom object associated with the BV,
    809:    to be used in operations that need random numbers.

    811:    Collective on bv

    813:    Input Parameters:
    814: +  bv   - the basis vectors context
    815: -  rand - the random number generator context

    817:    Level: advanced

    819: .seealso: BVGetRandomContext(), BVSetRandom(), BVSetRandomColumn()
    820: @*/
    821: PetscErrorCode BVSetRandomContext(BV bv,PetscRandom rand)
    822: {

    829:   PetscObjectReference((PetscObject)rand);
    830:   PetscRandomDestroy(&bv->rand);
    831:   bv->rand = rand;
    832:   PetscLogObjectParent((PetscObject)bv,(PetscObject)bv->rand);
    833:   return(0);
    834: }

    836: /*@
    837:    BVGetRandomContext - Gets the PetscRandom object associated with the BV.

    839:    Not Collective

    841:    Input Parameter:
    842: .  bv - the basis vectors context

    844:    Output Parameter:
    845: .  rand - the random number generator context

    847:    Level: advanced

    849: .seealso: BVSetRandomContext(), BVSetRandom(), BVSetRandomColumn()
    850: @*/
    851: PetscErrorCode BVGetRandomContext(BV bv,PetscRandom* rand)
    852: {

    858:   if (!bv->rand) {
    859:     PetscRandomCreate(PetscObjectComm((PetscObject)bv),&bv->rand);
    860:     PetscLogObjectParent((PetscObject)bv,(PetscObject)bv->rand);
    861:     if (bv->rrandom) {
    862:       PetscRandomSetSeed(bv->rand,0x12345678);
    863:       PetscRandomSeed(bv->rand);
    864:     }
    865:   }
    866:   *rand = bv->rand;
    867:   return(0);
    868: }

    870: /*@
    871:    BVSetFromOptions - Sets BV options from the options database.

    873:    Collective on bv

    875:    Input Parameter:
    876: .  bv - the basis vectors context

    878:    Level: beginner
    879: @*/
    880: PetscErrorCode BVSetFromOptions(BV bv)
    881: {
    882:   PetscErrorCode     ierr;
    883:   char               type[256];
    884:   PetscBool          flg1,flg2,flg3,flg4;
    885:   PetscReal          r;
    886:   BVOrthogType       otype;
    887:   BVOrthogRefineType orefine;
    888:   BVOrthogBlockType  oblock;

    892:   BVRegisterAll();
    893:   PetscObjectOptionsBegin((PetscObject)bv);
    894:     PetscOptionsFList("-bv_type","Basis Vectors type","BVSetType",BVList,(char*)(((PetscObject)bv)->type_name?((PetscObject)bv)->type_name:BVSVEC),type,sizeof(type),&flg1);
    895:     if (flg1) {
    896:       BVSetType(bv,type);
    897:     } else if (!((PetscObject)bv)->type_name) {
    898:       BVSetType(bv,BVSVEC);
    899:     }

    901:     otype = bv->orthog_type;
    902:     PetscOptionsEnum("-bv_orthog_type","Orthogonalization method","BVSetOrthogonalization",BVOrthogTypes,(PetscEnum)otype,(PetscEnum*)&otype,&flg1);
    903:     orefine = bv->orthog_ref;
    904:     PetscOptionsEnum("-bv_orthog_refine","Iterative refinement mode during orthogonalization","BVSetOrthogonalization",BVOrthogRefineTypes,(PetscEnum)orefine,(PetscEnum*)&orefine,&flg2);
    905:     r = bv->orthog_eta;
    906:     PetscOptionsReal("-bv_orthog_eta","Parameter of iterative refinement during orthogonalization","BVSetOrthogonalization",r,&r,&flg3);
    907:     oblock = bv->orthog_block;
    908:     PetscOptionsEnum("-bv_orthog_block","Block orthogonalization method","BVSetOrthogonalization",BVOrthogBlockTypes,(PetscEnum)oblock,(PetscEnum*)&oblock,&flg4);
    909:     if (flg1 || flg2 || flg3 || flg4) { BVSetOrthogonalization(bv,otype,orefine,r,oblock); }

    911:     PetscOptionsEnum("-bv_matmult","Method for BVMatMult","BVSetMatMultMethod",BVMatMultTypes,(PetscEnum)bv->vmm,(PetscEnum*)&bv->vmm,NULL);

    913:     /* undocumented option to generate random vectors that are independent of the number of processes */
    914:     PetscOptionsGetBool(NULL,NULL,"-bv_reproducible_random",&bv->rrandom,NULL);

    916:     if (bv->ops->create) bv->defersfo = PETSC_TRUE;   /* defer call to setfromoptions */
    917:     else if (bv->ops->setfromoptions) {
    918:       (*bv->ops->setfromoptions)(PetscOptionsObject,bv);
    919:     }
    920:     PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)bv);
    921:   PetscOptionsEnd();

    923:   if (!bv->rand) { BVGetRandomContext(bv,&bv->rand); }
    924:   PetscRandomSetFromOptions(bv->rand);
    925:   return(0);
    926: }

    928: /*@
    929:    BVSetOrthogonalization - Specifies the method used for the orthogonalization of
    930:    vectors (classical or modified Gram-Schmidt with or without refinement), and
    931:    for the block-orthogonalization (simultaneous orthogonalization of a set of
    932:    vectors).

    934:    Logically Collective on bv

    936:    Input Parameters:
    937: +  bv     - the basis vectors context
    938: .  type   - the method of vector orthogonalization
    939: .  refine - type of refinement
    940: .  eta    - parameter for selective refinement
    941: -  block  - the method of block orthogonalization

    943:    Options Database Keys:
    944: +  -bv_orthog_type <type> - Where <type> is cgs for Classical Gram-Schmidt orthogonalization
    945:                          (default) or mgs for Modified Gram-Schmidt orthogonalization
    946: .  -bv_orthog_refine <ref> - Where <ref> is one of never, ifneeded (default) or always
    947: .  -bv_orthog_eta <eta> -  For setting the value of eta
    948: -  -bv_orthog_block <block> - Where <block> is the block-orthogonalization method

    950:    Notes:
    951:    The default settings work well for most problems.

    953:    The parameter eta should be a real value between 0 and 1 (or PETSC_DEFAULT).
    954:    The value of eta is used only when the refinement type is "ifneeded".

    956:    When using several processors, MGS is likely to result in bad scalability.

    958:    If the method set for block orthogonalization is GS, then the computation
    959:    is done column by column with the vector orthogonalization.

    961:    Level: advanced

    963: .seealso: BVOrthogonalizeColumn(), BVGetOrthogonalization(), BVOrthogType, BVOrthogRefineType, BVOrthogBlockType
    964: @*/
    965: PetscErrorCode BVSetOrthogonalization(BV bv,BVOrthogType type,BVOrthogRefineType refine,PetscReal eta,BVOrthogBlockType block)
    966: {
    973:   switch (type) {
    974:     case BV_ORTHOG_CGS:
    975:     case BV_ORTHOG_MGS:
    976:       bv->orthog_type = type;
    977:       break;
    978:     default:
    979:       SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Unknown orthogonalization type");
    980:   }
    981:   switch (refine) {
    982:     case BV_ORTHOG_REFINE_NEVER:
    983:     case BV_ORTHOG_REFINE_IFNEEDED:
    984:     case BV_ORTHOG_REFINE_ALWAYS:
    985:       bv->orthog_ref = refine;
    986:       break;
    987:     default:
    988:       SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Unknown refinement type");
    989:   }
    990:   if (eta == PETSC_DEFAULT) {
    991:     bv->orthog_eta = 0.7071;
    992:   } else {
    993:     if (eta <= 0.0 || eta > 1.0) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"Invalid eta value");
    994:     bv->orthog_eta = eta;
    995:   }
    996:   switch (block) {
    997:     case BV_ORTHOG_BLOCK_GS:
    998:     case BV_ORTHOG_BLOCK_CHOL:
    999:     case BV_ORTHOG_BLOCK_TSQR:
    1000:     case BV_ORTHOG_BLOCK_TSQRCHOL:
    1001:     case BV_ORTHOG_BLOCK_SVQB:
    1002:       bv->orthog_block = block;
    1003:       break;
    1004:     default:
    1005:       SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Unknown block orthogonalization type");
    1006:   }
    1007:   return(0);
    1008: }

    1010: /*@
    1011:    BVGetOrthogonalization - Gets the orthogonalization settings from the BV object.

    1013:    Not Collective

    1015:    Input Parameter:
    1016: .  bv - basis vectors context

    1018:    Output Parameter:
    1019: +  type   - the method of vector orthogonalization
    1020: .  refine - type of refinement
    1021: .  eta    - parameter for selective refinement
    1022: -  block  - the method of block orthogonalization

    1024:    Level: advanced

    1026: .seealso: BVOrthogonalizeColumn(), BVSetOrthogonalization(), BVOrthogType, BVOrthogRefineType, BVOrthogBlockType
    1027: @*/
    1028: PetscErrorCode BVGetOrthogonalization(BV bv,BVOrthogType *type,BVOrthogRefineType *refine,PetscReal *eta,BVOrthogBlockType *block)
    1029: {
    1032:   if (type)   *type   = bv->orthog_type;
    1033:   if (refine) *refine = bv->orthog_ref;
    1034:   if (eta)    *eta    = bv->orthog_eta;
    1035:   if (block)  *block  = bv->orthog_block;
    1036:   return(0);
    1037: }

    1039: /*@
    1040:    BVSetMatMultMethod - Specifies the method used for the BVMatMult() operation.

    1042:    Logically Collective on bv

    1044:    Input Parameters:
    1045: +  bv     - the basis vectors context
    1046: -  method - the method for the BVMatMult() operation

    1048:    Options Database Keys:
    1049: .  -bv_matmult <meth> - choose one of the methods: vecs, mat

    1051:    Notes:
    1052:    Allowed values are
    1053: +  BV_MATMULT_VECS - perform a matrix-vector multiply per each column
    1054: .  BV_MATMULT_MAT - carry out a Mat-Mat product with a dense matrix
    1055: -  BV_MATMULT_MAT_SAVE - this case is deprecated

    1057:    The default is BV_MATMULT_MAT except in the case of BVVECS.

    1059:    Level: advanced

    1061: .seealso: BVMatMult(), BVGetMatMultMethod(), BVMatMultType
    1062: @*/
    1063: PetscErrorCode BVSetMatMultMethod(BV bv,BVMatMultType method)
    1064: {

    1070:   switch (method) {
    1071:     case BV_MATMULT_VECS:
    1072:     case BV_MATMULT_MAT:
    1073:       bv->vmm = method;
    1074:       break;
    1075:     case BV_MATMULT_MAT_SAVE:
    1076:       PetscInfo(bv,"BV_MATMULT_MAT_SAVE is deprecated, using BV_MATMULT_MAT\n");
    1077:       bv->vmm = BV_MATMULT_MAT;
    1078:       break;
    1079:     default:
    1080:       SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Unknown matmult method");
    1081:   }
    1082:   return(0);
    1083: }

    1085: /*@
    1086:    BVGetMatMultMethod - Gets the method used for the BVMatMult() operation.

    1088:    Not Collective

    1090:    Input Parameter:
    1091: .  bv - basis vectors context

    1093:    Output Parameter:
    1094: .  method - the method for the BVMatMult() operation

    1096:    Level: advanced

    1098: .seealso: BVMatMult(), BVSetMatMultMethod(), BVMatMultType
    1099: @*/
    1100: PetscErrorCode BVGetMatMultMethod(BV bv,BVMatMultType *method)
    1101: {
    1105:   *method = bv->vmm;
    1106:   return(0);
    1107: }

    1109: /*@
    1110:    BVGetColumn - Returns a Vec object that contains the entries of the
    1111:    requested column of the basis vectors object.

    1113:    Logically Collective on bv

    1115:    Input Parameters:
    1116: +  bv - the basis vectors context
    1117: -  j  - the index of the requested column

    1119:    Output Parameter:
    1120: .  v  - vector containing the jth column

    1122:    Notes:
    1123:    The returned Vec must be seen as a reference (not a copy) of the BV
    1124:    column, that is, modifying the Vec will change the BV entries as well.

    1126:    The returned Vec must not be destroyed. BVRestoreColumn() must be
    1127:    called when it is no longer needed. At most, two columns can be fetched,
    1128:    that is, this function can only be called twice before the corresponding
    1129:    BVRestoreColumn() is invoked.

    1131:    A negative index j selects the i-th constraint, where i=-j. Constraints
    1132:    should not be modified.

    1134:    Level: beginner

    1136: .seealso: BVRestoreColumn(), BVInsertConstraints()
    1137: @*/
    1138: PetscErrorCode BVGetColumn(BV bv,PetscInt j,Vec *v)
    1139: {
    1141:   PetscInt       l;

    1146:   BVCheckSizes(bv,1);
    1147:   BVCheckOp(bv,1,getcolumn);
    1149:   if (j<0 && -j>bv->nc) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"You requested constraint %D but only %D are available",-j,bv->nc);
    1150:   if (j>=bv->m) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"You requested column %D but only %D are available",j,bv->m);
    1151:   if (j==bv->ci[0] || j==bv->ci[1]) SETERRQ1(PetscObjectComm((PetscObject)bv),PETSC_ERR_SUP,"Column %D already fetched in a previous call to BVGetColumn",j);
    1152:   l = BVAvailableVec;
    1153:   if (l==-1) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_SUP,"Too many requested columns; you must call BVRestoreColumn for one of the previously fetched columns");
    1154:   (*bv->ops->getcolumn)(bv,j,v);
    1155:   bv->ci[l] = j;
    1156:   PetscObjectStateGet((PetscObject)bv->cv[l],&bv->st[l]);
    1157:   PetscObjectGetId((PetscObject)bv->cv[l],&bv->id[l]);
    1158:   *v = bv->cv[l];
    1159:   return(0);
    1160: }

    1162: /*@
    1163:    BVRestoreColumn - Restore a column obtained with BVGetColumn().

    1165:    Logically Collective on bv

    1167:    Input Parameters:
    1168: +  bv - the basis vectors context
    1169: .  j  - the index of the column
    1170: -  v  - vector obtained with BVGetColumn()

    1172:    Note:
    1173:    The arguments must match the corresponding call to BVGetColumn().

    1175:    Level: beginner

    1177: .seealso: BVGetColumn()
    1178: @*/
    1179: PetscErrorCode BVRestoreColumn(BV bv,PetscInt j,Vec *v)
    1180: {
    1181:   PetscErrorCode   ierr;
    1182:   PetscObjectId    id;
    1183:   PetscObjectState st;
    1184:   PetscInt         l;

    1189:   BVCheckSizes(bv,1);
    1193:   if (j<0 && -j>bv->nc) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"You requested constraint %D but only %D are available",-j,bv->nc);
    1194:   if (j>=bv->m) SETERRQ2(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"You requested column %D but only %D are available",j,bv->m);
    1195:   if (j!=bv->ci[0] && j!=bv->ci[1]) SETERRQ1(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Column %D has not been fetched with a call to BVGetColumn",j);
    1196:   l = (j==bv->ci[0])? 0: 1;
    1197:   PetscObjectGetId((PetscObject)*v,&id);
    1198:   if (id!=bv->id[l]) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Argument 3 is not the same Vec that was obtained with BVGetColumn");
    1199:   PetscObjectStateGet((PetscObject)*v,&st);
    1200:   if (st!=bv->st[l]) {
    1201:     PetscObjectStateIncrease((PetscObject)bv);
    1202:   }
    1203:   if (bv->ops->restorecolumn) {
    1204:     (*bv->ops->restorecolumn)(bv,j,v);
    1205:   } else bv->cv[l] = NULL;
    1206:   bv->ci[l] = -bv->nc-1;
    1207:   bv->st[l] = -1;
    1208:   bv->id[l] = 0;
    1209:   *v = NULL;
    1210:   return(0);
    1211: }

    1213: /*@C
    1214:    BVGetArray - Returns a pointer to a contiguous array that contains this
    1215:    processor's portion of the BV data.

    1217:    Logically Collective on bv

    1219:    Input Parameters:
    1220: .  bv - the basis vectors context

    1222:    Output Parameter:
    1223: .  a  - location to put pointer to the array

    1225:    Notes:
    1226:    BVRestoreArray() must be called when access to the array is no longer needed.
    1227:    This operation may imply a data copy, for BV types that do not store
    1228:    data contiguously in memory.

    1230:    The pointer will normally point to the first entry of the first column,
    1231:    but if the BV has constraints then these go before the regular columns.

    1233:    Level: advanced

    1235: .seealso: BVRestoreArray(), BVInsertConstraints()
    1236: @*/
    1237: PetscErrorCode BVGetArray(BV bv,PetscScalar **a)
    1238: {

    1244:   BVCheckSizes(bv,1);
    1245:   BVCheckOp(bv,1,getarray);
    1246:   (*bv->ops->getarray)(bv,a);
    1247:   return(0);
    1248: }

    1250: /*@C
    1251:    BVRestoreArray - Restore the BV object after BVGetArray() has been called.

    1253:    Logically Collective on bv

    1255:    Input Parameters:
    1256: +  bv - the basis vectors context
    1257: -  a  - location of pointer to array obtained from BVGetArray()

    1259:    Note:
    1260:    This operation may imply a data copy, for BV types that do not store
    1261:    data contiguously in memory.

    1263:    Level: advanced

    1265: .seealso: BVGetColumn()
    1266: @*/
    1267: PetscErrorCode BVRestoreArray(BV bv,PetscScalar **a)
    1268: {

    1274:   BVCheckSizes(bv,1);
    1275:   if (bv->ops->restorearray) {
    1276:     (*bv->ops->restorearray)(bv,a);
    1277:   }
    1278:   if (a) *a = NULL;
    1279:   PetscObjectStateIncrease((PetscObject)bv);
    1280:   return(0);
    1281: }

    1283: /*@C
    1284:    BVGetArrayRead - Returns a read-only pointer to a contiguous array that
    1285:    contains this processor's portion of the BV data.

    1287:    Not Collective

    1289:    Input Parameters:
    1290: .  bv - the basis vectors context

    1292:    Output Parameter:
    1293: .  a  - location to put pointer to the array

    1295:    Notes:
    1296:    BVRestoreArrayRead() must be called when access to the array is no
    1297:    longer needed. This operation may imply a data copy, for BV types that
    1298:    do not store data contiguously in memory.

    1300:    The pointer will normally point to the first entry of the first column,
    1301:    but if the BV has constraints then these go before the regular columns.

    1303:    Level: advanced

    1305: .seealso: BVRestoreArray(), BVInsertConstraints()
    1306: @*/
    1307: PetscErrorCode BVGetArrayRead(BV bv,const PetscScalar **a)
    1308: {

    1314:   BVCheckSizes(bv,1);
    1315:   BVCheckOp(bv,1,getarrayread);
    1316:   (*bv->ops->getarrayread)(bv,a);
    1317:   return(0);
    1318: }

    1320: /*@C
    1321:    BVRestoreArrayRead - Restore the BV object after BVGetArrayRead() has
    1322:    been called.

    1324:    Not Collective

    1326:    Input Parameters:
    1327: +  bv - the basis vectors context
    1328: -  a  - location of pointer to array obtained from BVGetArrayRead()

    1330:    Level: advanced

    1332: .seealso: BVGetColumn()
    1333: @*/
    1334: PetscErrorCode BVRestoreArrayRead(BV bv,const PetscScalar **a)
    1335: {

    1341:   BVCheckSizes(bv,1);
    1342:   if (bv->ops->restorearrayread) {
    1343:     (*bv->ops->restorearrayread)(bv,a);
    1344:   }
    1345:   if (a) *a = NULL;
    1346:   return(0);
    1347: }

    1349: /*@
    1350:    BVCreateVec - Creates a new Vec object with the same type and dimensions
    1351:    as the columns of the basis vectors object.

    1353:    Collective on bv

    1355:    Input Parameter:
    1356: .  bv - the basis vectors context

    1358:    Output Parameter:
    1359: .  v  - the new vector

    1361:    Note:
    1362:    The user is responsible of destroying the returned vector.

    1364:    Level: beginner

    1366: .seealso: BVCreateMat()
    1367: @*/
    1368: PetscErrorCode BVCreateVec(BV bv,Vec *v)
    1369: {

    1374:   BVCheckSizes(bv,1);
    1376:   VecDuplicate(bv->t,v);
    1377:   return(0);
    1378: }

    1380: /*@
    1381:    BVCreateMat - Creates a new Mat object of dense type and copies the contents
    1382:    of the BV object.

    1384:    Collective on bv

    1386:    Input Parameter:
    1387: .  bv - the basis vectors context

    1389:    Output Parameter:
    1390: .  A  - the new matrix

    1392:    Notes:
    1393:    The user is responsible of destroying the returned matrix.

    1395:    The matrix contains all columns of the BV, not just the active columns.

    1397:    Level: intermediate

    1399: .seealso: BVCreateFromMat(), BVCreateVec(), BVGetMat()
    1400: @*/
    1401: PetscErrorCode BVCreateMat(BV bv,Mat *A)
    1402: {
    1403:   PetscErrorCode    ierr;
    1404:   PetscScalar       *aa;
    1405:   const PetscScalar *vv;

    1409:   BVCheckSizes(bv,1);

    1412:   MatCreateDense(PetscObjectComm((PetscObject)bv->t),bv->n,PETSC_DECIDE,bv->N,bv->m,NULL,A);
    1413:   MatDenseGetArray(*A,&aa);
    1414:   BVGetArrayRead(bv,&vv);
    1415:   PetscArraycpy(aa,vv,bv->m*bv->n);
    1416:   BVRestoreArrayRead(bv,&vv);
    1417:   MatDenseRestoreArray(*A,&aa);
    1418:   MatAssemblyBegin(*A,MAT_FINAL_ASSEMBLY);
    1419:   MatAssemblyEnd(*A,MAT_FINAL_ASSEMBLY);
    1420:   return(0);
    1421: }

    1423: /*@
    1424:    BVGetMat - Returns a Mat object of dense type that shares the memory of
    1425:    the BV object.

    1427:    Collective on bv

    1429:    Input Parameter:
    1430: .  bv - the basis vectors context

    1432:    Output Parameter:
    1433: .  A  - the matrix

    1435:    Notes:
    1436:    The returned matrix contains only the active columns. If the content of
    1437:    the Mat is modified, these changes are also done in the BV object. The
    1438:    user must call BVRestoreMat() when no longer needed.

    1440:    This operation implies a call to BVGetArray(), which may result in data
    1441:    copies.

    1443:    Level: advanced

    1445: .seealso: BVRestoreMat(), BVCreateMat(), BVGetArray()
    1446: @*/
    1447: PetscErrorCode BVGetMat(BV bv,Mat *A)
    1448: {
    1450:   PetscScalar    *vv,*aa;
    1451:   PetscBool      create=PETSC_FALSE;
    1452:   PetscInt       m,cols;

    1456:   BVCheckSizes(bv,1);
    1458:   if (bv->ops->getmat) {
    1459:     (*bv->ops->getmat)(bv,A);
    1460:   } else {
    1461:     m = bv->k-bv->l;
    1462:     if (!bv->Aget) create=PETSC_TRUE;
    1463:     else {
    1464:       MatDenseGetArray(bv->Aget,&aa);
    1465:       if (aa) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"BVGetMat already called on this BV");
    1466:       MatGetSize(bv->Aget,NULL,&cols);
    1467:       if (cols!=m) {
    1468:         MatDestroy(&bv->Aget);
    1469:         create=PETSC_TRUE;
    1470:       }
    1471:     }
    1472:     BVGetArray(bv,&vv);
    1473:     if (create) {
    1474:       MatCreateDense(PetscObjectComm((PetscObject)bv),bv->n,PETSC_DECIDE,bv->N,m,vv,&bv->Aget); /* pass a pointer to avoid allocation of storage */
    1475:       MatDenseReplaceArray(bv->Aget,NULL);  /* replace with a null pointer, the value after BVRestoreMat */
    1476:       PetscLogObjectParent((PetscObject)bv,(PetscObject)bv->Aget);
    1477:     }
    1478:     MatDensePlaceArray(bv->Aget,vv+(bv->nc+bv->l)*bv->n);  /* set the actual pointer */
    1479:     *A = bv->Aget;
    1480:   }
    1481:   return(0);
    1482: }

    1484: /*@
    1485:    BVRestoreMat - Restores the Mat obtained with BVGetMat().

    1487:    Logically Collective on bv

    1489:    Input Parameters:
    1490: +  bv - the basis vectors context
    1491: -  A  - the fetched matrix

    1493:    Note:
    1494:    A call to this function must match a previous call of BVGetMat().
    1495:    The effect is that the contents of the Mat are copied back to the
    1496:    BV internal data structures.

    1498:    Level: advanced

    1500: .seealso: BVGetMat(), BVRestoreArray()
    1501: @*/
    1502: PetscErrorCode BVRestoreMat(BV bv,Mat *A)
    1503: {
    1505:   PetscScalar    *vv,*aa;

    1509:   BVCheckSizes(bv,1);
    1511:   if (!bv->Aget) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"BVRestoreMat must match a previous call to BVGetMat");
    1512:   if (bv->Aget!=*A) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Mat argument is not the same as the one obtained with BVGetMat");
    1513:   if (bv->ops->restoremat) {
    1514:     (*bv->ops->restoremat)(bv,A);
    1515:   } else {
    1516:     MatDenseGetArray(bv->Aget,&aa);
    1517:     vv = aa-(bv->nc+bv->l)*bv->n;
    1518:     MatDenseResetArray(bv->Aget);
    1519:     BVRestoreArray(bv,&vv);
    1520:     *A = NULL;
    1521:   }
    1522:   return(0);
    1523: }

    1525: /*
    1526:    Copy all user-provided attributes of V to another BV object W
    1527:  */
    1528: PETSC_STATIC_INLINE PetscErrorCode BVDuplicate_Private(BV V,BV W)
    1529: {

    1533:   BVSetType(W,((PetscObject)V)->type_name);
    1534:   W->orthog_type  = V->orthog_type;
    1535:   W->orthog_ref   = V->orthog_ref;
    1536:   W->orthog_eta   = V->orthog_eta;
    1537:   W->orthog_block = V->orthog_block;
    1538:   if (V->matrix) { PetscObjectReference((PetscObject)V->matrix); }
    1539:   W->matrix       = V->matrix;
    1540:   W->indef        = V->indef;
    1541:   W->vmm          = V->vmm;
    1542:   W->rrandom      = V->rrandom;
    1543:   if (V->rand) { PetscObjectReference((PetscObject)V->rand); }
    1544:   W->rand         = V->rand;
    1545:   if (V->ops->duplicate) { (*V->ops->duplicate)(V,W); }
    1546:   PetscObjectStateIncrease((PetscObject)W);
    1547:   return(0);
    1548: }

    1550: /*@
    1551:    BVDuplicate - Creates a new basis vector object of the same type and
    1552:    dimensions as an existing one.

    1554:    Collective on V

    1556:    Input Parameter:
    1557: .  V - basis vectors context

    1559:    Output Parameter:
    1560: .  W - location to put the new BV

    1562:    Notes:
    1563:    The new BV has the same type and dimensions as V, and it shares the same
    1564:    template vector. Also, the inner product matrix and orthogonalization
    1565:    options are copied.

    1567:    BVDuplicate() DOES NOT COPY the entries, but rather allocates storage
    1568:    for the new basis vectors. Use BVCopy() to copy the contents.

    1570:    Level: intermediate

    1572: .seealso: BVDuplicateResize(), BVCreate(), BVSetSizesFromVec(), BVCopy()
    1573: @*/
    1574: PetscErrorCode BVDuplicate(BV V,BV *W)
    1575: {

    1581:   BVCheckSizes(V,1);
    1583:   BVCreate(PetscObjectComm((PetscObject)V),W);
    1584:   BVSetSizesFromVec(*W,V->t,V->m);
    1585:   BVDuplicate_Private(V,*W);
    1586:   return(0);
    1587: }

    1589: /*@
    1590:    BVDuplicateResize - Creates a new basis vector object of the same type and
    1591:    dimensions as an existing one, but with possibly different number of columns.

    1593:    Collective on V

    1595:    Input Parameter:
    1596: +  V - basis vectors context
    1597: -  m - the new number of columns

    1599:    Output Parameter:
    1600: .  W - location to put the new BV

    1602:    Note:
    1603:    This is equivalent of a call to BVDuplicate() followed by BVResize(). The
    1604:    contents of V are not copied to W.

    1606:    Level: intermediate

    1608: .seealso: BVDuplicate(), BVResize()
    1609: @*/
    1610: PetscErrorCode BVDuplicateResize(BV V,PetscInt m,BV *W)
    1611: {

    1617:   BVCheckSizes(V,1);
    1620:   BVCreate(PetscObjectComm((PetscObject)V),W);
    1621:   BVSetSizesFromVec(*W,V->t,m);
    1622:   BVDuplicate_Private(V,*W);
    1623:   return(0);
    1624: }

    1626: /*@
    1627:    BVGetCachedBV - Returns a BV object stored internally that holds the
    1628:    result of B*X after a call to BVApplyMatrixBV().

    1630:    Not collective

    1632:    Input Parameter:
    1633: .  bv    - the basis vectors context

    1635:    Output Parameter:
    1636: .  cached - the cached BV

    1638:    Note:
    1639:    The cached BV is created if not available previously.

    1641:    Level: developer

    1643: .seealso: BVApplyMatrixBV()
    1644: @*/
    1645: PetscErrorCode BVGetCachedBV(BV bv,BV *cached)
    1646: {

    1652:   BVCheckSizes(bv,1);
    1653:   if (!bv->cached) {
    1654:     BVCreate(PetscObjectComm((PetscObject)bv),&bv->cached);
    1655:     BVSetSizesFromVec(bv->cached,bv->t,bv->m);
    1656:     BVDuplicate_Private(bv,bv->cached);
    1657:     PetscLogObjectParent((PetscObject)bv,(PetscObject)bv->cached);
    1658:   }
    1659:   *cached = bv->cached;
    1660:   return(0);
    1661: }

    1663: /*@
    1664:    BVCopy - Copies a basis vector object into another one, W <- V.

    1666:    Logically Collective on V

    1668:    Input Parameter:
    1669: .  V - basis vectors context

    1671:    Output Parameter:
    1672: .  W - the copy

    1674:    Note:
    1675:    Both V and W must be distributed in the same manner; local copies are
    1676:    done. Only active columns (excluding the leading ones) are copied.
    1677:    In the destination W, columns are overwritten starting from the leading ones.
    1678:    Constraints are not copied.

    1680:    Level: beginner

    1682: .seealso: BVCopyVec(), BVCopyColumn(), BVDuplicate(), BVSetActiveColumns()
    1683: @*/
    1684: PetscErrorCode BVCopy(BV V,BV W)
    1685: {
    1686:   PetscErrorCode    ierr;
    1687:   PetscScalar       *womega;
    1688:   const PetscScalar *vomega;

    1693:   BVCheckSizes(V,1);
    1694:   BVCheckOp(V,1,copy);
    1697:   BVCheckSizes(W,2);
    1699:   if (V->n!=W->n) SETERRQ2(PetscObjectComm((PetscObject)V),PETSC_ERR_ARG_INCOMP,"Mismatching local dimension V %D, W %D",V->n,W->n);
    1700:   if (V->k-V->l>W->m-W->l) SETERRQ2(PetscObjectComm((PetscObject)V),PETSC_ERR_ARG_SIZ,"W has %D non-leading columns, not enough to store %D columns",W->m-W->l,V->k-V->l);
    1701:   if (V==W || !V->n) return(0);

    1703:   PetscLogEventBegin(BV_Copy,V,W,0,0);
    1704:   if (V->indef && V->matrix && V->indef==W->indef && V->matrix==W->matrix) {
    1705:     /* copy signature */
    1706:     BV_AllocateSignature(W);
    1707:     VecGetArrayRead(V->omega,&vomega);
    1708:     VecGetArray(W->omega,&womega);
    1709:     PetscArraycpy(womega+W->nc+W->l,vomega+V->nc+V->l,V->k-V->l);
    1710:     VecRestoreArray(W->omega,&womega);
    1711:     VecRestoreArrayRead(V->omega,&vomega);
    1712:   }
    1713:   (*V->ops->copy)(V,W);
    1714:   PetscLogEventEnd(BV_Copy,V,W,0,0);
    1715:   PetscObjectStateIncrease((PetscObject)W);
    1716:   return(0);
    1717: }

    1719: /*@
    1720:    BVCopyVec - Copies one of the columns of a basis vectors object into a Vec.

    1722:    Logically Collective on V

    1724:    Input Parameter:
    1725: +  V - basis vectors context
    1726: -  j - the column number to be copied

    1728:    Output Parameter:
    1729: .  w - the copied column

    1731:    Note:
    1732:    Both V and w must be distributed in the same manner; local copies are done.

    1734:    Level: beginner

    1736: .seealso: BVCopy(), BVCopyColumn(), BVInsertVec()
    1737: @*/
    1738: PetscErrorCode BVCopyVec(BV V,PetscInt j,Vec w)
    1739: {
    1741:   PetscInt       n,N;
    1742:   Vec            z;

    1747:   BVCheckSizes(V,1);

    1752:   VecGetSize(w,&N);
    1753:   VecGetLocalSize(w,&n);
    1754:   if (N!=V->N || n!=V->n) SETERRQ4(PetscObjectComm((PetscObject)V),PETSC_ERR_ARG_INCOMP,"Vec sizes (global %D, local %D) do not match BV sizes (global %D, local %D)",N,n,V->N,V->n);

    1756:   PetscLogEventBegin(BV_Copy,V,w,0,0);
    1757:   BVGetColumn(V,j,&z);
    1758:   VecCopy(z,w);
    1759:   BVRestoreColumn(V,j,&z);
    1760:   PetscLogEventEnd(BV_Copy,V,w,0,0);
    1761:   return(0);
    1762: }

    1764: /*@
    1765:    BVCopyColumn - Copies the values from one of the columns to another one.

    1767:    Logically Collective on V

    1769:    Input Parameter:
    1770: +  V - basis vectors context
    1771: .  j - the number of the source column
    1772: -  i - the number of the destination column

    1774:    Level: beginner

    1776: .seealso: BVCopy(), BVCopyVec()
    1777: @*/
    1778: PetscErrorCode BVCopyColumn(BV V,PetscInt j,PetscInt i)
    1779: {
    1781:   Vec            z,w;
    1782:   PetscScalar    *omega;

    1787:   BVCheckSizes(V,1);
    1790:   if (j==i) return(0);

    1792:   PetscLogEventBegin(BV_Copy,V,0,0,0);
    1793:   if (V->omega) {
    1794:     VecGetArray(V->omega,&omega);
    1795:     omega[i] = omega[j];
    1796:     VecRestoreArray(V->omega,&omega);
    1797:   }
    1798:   if (V->ops->copycolumn) {
    1799:     (*V->ops->copycolumn)(V,j,i);
    1800:   } else {
    1801:     BVGetColumn(V,j,&z);
    1802:     BVGetColumn(V,i,&w);
    1803:     VecCopy(z,w);
    1804:     BVRestoreColumn(V,j,&z);
    1805:     BVRestoreColumn(V,i,&w);
    1806:   }
    1807:   PetscLogEventEnd(BV_Copy,V,0,0,0);
    1808:   PetscObjectStateIncrease((PetscObject)V);
    1809:   return(0);
    1810: }

    1812: static PetscErrorCode BVGetSplit_Private(BV bv,PetscBool left,BV *split)
    1813: {
    1815:   PetscInt       ncols;

    1818:   ncols = left? bv->nc+bv->l: bv->m-bv->l;
    1819:   if (*split && ncols!=(*split)->m) { BVDestroy(split); }
    1820:   if (!*split) {
    1821:     BVCreate(PetscObjectComm((PetscObject)bv),split);
    1822:     PetscLogObjectParent((PetscObject)bv,(PetscObject)*split);
    1823:     (*split)->issplit = left? 1: 2;
    1824:     (*split)->splitparent = bv;
    1825:     BVSetSizesFromVec(*split,bv->t,ncols);
    1826:     BVDuplicate_Private(bv,*split);
    1827:   }
    1828:   (*split)->l  = 0;
    1829:   (*split)->k  = left? bv->l: bv->k-bv->l;
    1830:   (*split)->nc = left? bv->nc: 0;
    1831:   (*split)->m  = ncols-(*split)->nc;
    1832:   if ((*split)->nc) {
    1833:     (*split)->ci[0] = -(*split)->nc-1;
    1834:     (*split)->ci[1] = -(*split)->nc-1;
    1835:   }
    1836:   if (left) {
    1837:     PetscObjectStateGet((PetscObject)*split,&bv->lstate);
    1838:   } else {
    1839:     PetscObjectStateGet((PetscObject)*split,&bv->rstate);
    1840:   }
    1841:   return(0);
    1842: }

    1844: /*@
    1845:    BVGetSplit - Splits the BV object into two BV objects that share the
    1846:    internal data, one of them containing the leading columns and the other
    1847:    one containing the remaining columns.

    1849:    Logically Collective on bv

    1851:    Input Parameters:
    1852: .  bv - the basis vectors context

    1854:    Output Parameters:
    1855: +  L - left BV containing leading columns (can be NULL)
    1856: -  R - right BV containing remaining columns (can be NULL)

    1858:    Notes:
    1859:    The columns are split in two sets. The leading columns (including the
    1860:    constraints) are assigned to the left BV and the remaining columns
    1861:    are assigned to the right BV. The number of leading columns, as
    1862:    specified with BVSetActiveColumns(), must be between 1 and m-1 (to
    1863:    guarantee that both L and R have at least one column).

    1865:    The returned BV's must be seen as references (not copies) of the input
    1866:    BV, that is, modifying them will change the entries of bv as well.
    1867:    The returned BV's must not be destroyed. BVRestoreSplit() must be called
    1868:    when they are no longer needed.

    1870:    Pass NULL for any of the output BV's that is not needed.

    1872:    Level: advanced

    1874: .seealso: BVRestoreSplit(), BVSetActiveColumns(), BVSetNumConstraints()
    1875: @*/
    1876: PetscErrorCode BVGetSplit(BV bv,BV *L,BV *R)
    1877: {

    1883:   BVCheckSizes(bv,1);
    1884:   if (!bv->l) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Must indicate the number of leading columns with BVSetActiveColumns()");
    1885:   if (bv->lsplit) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Cannot get the split BV's twice before restoring them with BVRestoreSplit()");
    1886:   bv->lsplit = bv->nc+bv->l;
    1887:   BVGetSplit_Private(bv,PETSC_TRUE,&bv->L);
    1888:   BVGetSplit_Private(bv,PETSC_FALSE,&bv->R);
    1889:   if (L) *L = bv->L;
    1890:   if (R) *R = bv->R;
    1891:   return(0);
    1892: }

    1894: /*@
    1895:    BVRestoreSplit - Restore the BV objects obtained with BVGetSplit().

    1897:    Logically Collective on bv

    1899:    Input Parameters:
    1900: +  bv - the basis vectors context
    1901: .  L  - left BV obtained with BVGetSplit()
    1902: -  R  - right BV obtained with BVGetSplit()

    1904:    Note:
    1905:    The arguments must match the corresponding call to BVGetSplit().

    1907:    Level: advanced

    1909: .seealso: BVGetSplit()
    1910: @*/
    1911: PetscErrorCode BVRestoreSplit(BV bv,BV *L,BV *R)
    1912: {

    1918:   BVCheckSizes(bv,1);
    1919:   if (!bv->lsplit) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Must call BVGetSplit first");
    1920:   if (L && *L!=bv->L) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Argument 2 is not the same BV that was obtained with BVGetSplit");
    1921:   if (R && *R!=bv->R) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Argument 3 is not the same BV that was obtained with BVGetSplit");
    1922:   if (L && ((*L)->ci[0]>(*L)->nc-1 || (*L)->ci[1]>(*L)->nc-1)) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Argument 2 has unrestored columns, use BVRestoreColumn()");
    1923:   if (R && ((*R)->ci[0]>(*R)->nc-1 || (*R)->ci[1]>(*R)->nc-1)) SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Argument 3 has unrestored columns, use BVRestoreColumn()");

    1925:   if (bv->ops->restoresplit) {
    1926:     (*bv->ops->restoresplit)(bv,L,R);
    1927:   }
    1928:   bv->lsplit = 0;
    1929:   if (L) *L = NULL;
    1930:   if (R) *R = NULL;
    1931:   return(0);
    1932: }