Actual source code: bvbasic.c
slepc-3.21.1 2024-04-26
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain

      6:    This file is part of SLEPc.
      7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
      8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      9: */
     10: /*
     11:    Basic BV routines
     12: */

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

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

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

     22:    Logically Collective

     24:    Input Parameters:
     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 (*r)(BV);
     38:   PetscBool      match;

     40:   PetscFunctionBegin;
     42:   PetscAssertPointer(type,2);

     44:   PetscCall(PetscObjectTypeCompare((PetscObject)bv,type,&match));
     45:   if (match) PetscFunctionReturn(PETSC_SUCCESS);
     46:   PetscCall(PetscStrcmp(type,BVTENSOR,&match));
     47:   PetscCheck(!match,PetscObjectComm((PetscObject)bv),PETSC_ERR_ORDER,"Use BVCreateTensor() to create a BV of type tensor");

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

     52:   PetscTryTypeMethod(bv,destroy);
     53:   PetscCall(PetscMemzero(bv->ops,sizeof(struct _BVOps)));

     55:   PetscCall(PetscObjectChangeTypeName((PetscObject)bv,type));
     56:   if (bv->n < 0 && bv->N < 0) {
     57:     bv->ops->create = r;
     58:   } else {
     59:     PetscCall(PetscLogEventBegin(BV_Create,bv,0,0,0));
     60:     PetscCall((*r)(bv));
     61:     PetscCall(PetscLogEventEnd(BV_Create,bv,0,0,0));
     62:   }
     63:   PetscFunctionReturn(PETSC_SUCCESS);
     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: .  type - name of the type of basis vectors

     77:    Level: intermediate

     79: .seealso: BVSetType()
     80: @*/
     81: PetscErrorCode BVGetType(BV bv,BVType *type)
     82: {
     83:   PetscFunctionBegin;
     85:   PetscAssertPointer(type,2);
     86:   *type = ((PetscObject)bv)->type_name;
     87:   PetscFunctionReturn(PETSC_SUCCESS);
     88: }

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

     93:    Collective

     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: {
    112:   PetscInt       ma;
    113:   PetscMPIInt    size;

    115:   PetscFunctionBegin;
    119:   PetscCheck(N<0 || n<=N,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Local size %" PetscInt_FMT " cannot be larger than global size %" PetscInt_FMT,n,N);
    120:   PetscCheck(m>0,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Number of columns %" PetscInt_FMT " must be positive",m);
    121:   PetscCheck((bv->n<0 && bv->N<0) || (bv->n==n && bv->N==N),PetscObjectComm((PetscObject)bv),PETSC_ERR_SUP,"Cannot change/reset vector sizes to %" PetscInt_FMT " local %" PetscInt_FMT " global after previously setting them to %" PetscInt_FMT " local %" PetscInt_FMT " global",n,N,bv->n,bv->N);
    122:   PetscCheck(bv->m<=0 || bv->m==m,PetscObjectComm((PetscObject)bv),PETSC_ERR_SUP,"Cannot change the number of columns to %" PetscInt_FMT " after previously setting it to %" PetscInt_FMT "; use BVResize()",m,bv->m);
    123:   PetscCheck(!bv->map,PetscObjectComm((PetscObject)bv),PETSC_ERR_SUP,"Vector layout was already defined by a previous call to BVSetSizes/FromVec");
    124:   bv->n = n;
    125:   bv->N = N;
    126:   bv->m = m;
    127:   bv->k = m;
    128:   /* create layout and get actual dimensions */
    129:   PetscCall(PetscLayoutCreate(PetscObjectComm((PetscObject)bv),&bv->map));
    130:   PetscCall(PetscLayoutSetSize(bv->map,bv->N));
    131:   PetscCall(PetscLayoutSetLocalSize(bv->map,bv->n));
    132:   PetscCall(PetscLayoutSetUp(bv->map));
    133:   PetscCall(PetscLayoutGetSize(bv->map,&bv->N));
    134:   PetscCall(PetscLayoutGetLocalSize(bv->map,&bv->n));
    135:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)bv),&size));
    136:   PetscCall(BVSetVecType(bv,(size==1)?VECSEQ:VECMPI));
    137:   if (bv->matrix) {  /* check compatible dimensions of user-provided matrix */
    138:     PetscCall(MatGetLocalSize(bv->matrix,&ma,NULL));
    139:     PetscCheck(bv->n==ma,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Local dimension %" PetscInt_FMT " does not match that of matrix given at BVSetMatrix %" PetscInt_FMT,bv->n,ma);
    140:   }
    141:   if (bv->ops->create) {
    142:     PetscCall(PetscLogEventBegin(BV_Create,bv,0,0,0));
    143:     PetscUseTypeMethod(bv,create);
    144:     PetscCall(PetscLogEventEnd(BV_Create,bv,0,0,0));
    145:     bv->ops->create = NULL;
    146:     bv->defersfo = PETSC_FALSE;
    147:   }
    148:   PetscFunctionReturn(PETSC_SUCCESS);
    149: }

    151: /*@
    152:    BVSetSizesFromVec - Sets the local and global sizes, and the number of columns.
    153:    Local and global sizes are specified indirectly by passing a template vector.

    155:    Collective

    157:    Input Parameters:
    158: +  bv - the basis vectors
    159: .  t  - the template vector
    160: -  m  - the number of columns

    162:    Level: beginner

    164: .seealso: BVSetSizes(), BVGetSizes(), BVResize()
    165: @*/
    166: PetscErrorCode BVSetSizesFromVec(BV bv,Vec t,PetscInt m)
    167: {
    168:   PetscInt       ma;
    169:   PetscLayout    map;
    170:   VecType        vtype;

    172:   PetscFunctionBegin;
    175:   PetscCheckSameComm(bv,1,t,2);
    177:   PetscCheck(m>0,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Number of columns %" PetscInt_FMT " must be positive",m);
    178:   PetscCheck(!bv->map,PetscObjectComm((PetscObject)bv),PETSC_ERR_SUP,"Vector layout was already defined by a previous call to BVSetSizes/FromVec");
    179:   PetscCall(VecGetType(t,&vtype));
    180:   PetscCall(BVSetVecType(bv,vtype));
    181:   PetscCall(VecGetLayout(t,&map));
    182:   PetscCall(PetscLayoutReference(map,&bv->map));
    183:   PetscCall(VecGetSize(t,&bv->N));
    184:   PetscCall(VecGetLocalSize(t,&bv->n));
    185:   if (bv->matrix) {  /* check compatible dimensions of user-provided matrix */
    186:     PetscCall(MatGetLocalSize(bv->matrix,&ma,NULL));
    187:     PetscCheck(bv->n==ma,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Local dimension %" PetscInt_FMT " does not match that of matrix given at BVSetMatrix %" PetscInt_FMT,bv->n,ma);
    188:   }
    189:   bv->m = m;
    190:   bv->k = m;
    191:   if (bv->ops->create) {
    192:     PetscUseTypeMethod(bv,create);
    193:     bv->ops->create = NULL;
    194:     bv->defersfo = PETSC_FALSE;
    195:   }
    196:   PetscFunctionReturn(PETSC_SUCCESS);
    197: }

    199: /*@
    200:    BVGetSizes - Returns the local and global sizes, and the number of columns.

    202:    Not Collective

    204:    Input Parameter:
    205: .  bv - the basis vectors

    207:    Output Parameters:
    208: +  n  - the local size
    209: .  N  - the global size
    210: -  m  - the number of columns

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

    219:    Level: beginner

    221: .seealso: BVSetSizes(), BVSetSizesFromVec()
    222: @*/
    223: PetscErrorCode BVGetSizes(BV bv,PetscInt *n,PetscInt *N,PetscInt *m)
    224: {
    225:   PetscFunctionBegin;
    226:   if (!bv) {
    227:     if (m && !n && !N) *m = 0;
    228:     PetscFunctionReturn(PETSC_SUCCESS);
    229:   }
    231:   if (n || N) BVCheckSizes(bv,1);
    232:   if (n) *n = bv->n;
    233:   if (N) *N = bv->N;
    234:   if (m) *m = bv->m;
    235:   if (m && !n && !N && !((PetscObject)bv)->type_name) *m = 0;
    236:   PetscFunctionReturn(PETSC_SUCCESS);
    237: }

    239: /*@
    240:    BVSetNumConstraints - Set the number of constraints.

    242:    Logically Collective

    244:    Input Parameters:
    245: +  V  - basis vectors
    246: -  nc - number of constraints

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

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

    256:    Level: developer

    258: .seealso: BVInsertConstraints()
    259: @*/
    260: PetscErrorCode BVSetNumConstraints(BV V,PetscInt nc)
    261: {
    262:   PetscInt       total,diff,i;
    263:   Vec            x,y;

    265:   PetscFunctionBegin;
    268:   PetscCheck(nc>=0,PetscObjectComm((PetscObject)V),PETSC_ERR_ARG_OUTOFRANGE,"Number of constraints (given %" PetscInt_FMT ") cannot be negative",nc);
    270:   BVCheckSizes(V,1);
    271:   PetscCheck(V->ci[0]==-V->nc-1 && V->ci[1]==-V->nc-1,PetscObjectComm((PetscObject)V),PETSC_ERR_SUP,"Cannot call BVSetNumConstraints after BVGetColumn");

    273:   diff = nc-V->nc;
    274:   if (!diff) PetscFunctionReturn(PETSC_SUCCESS);
    275:   total = V->nc+V->m;
    276:   PetscCheck(total-nc>0,PetscObjectComm((PetscObject)V),PETSC_ERR_ARG_OUTOFRANGE,"Not enough columns for the given nc value");
    277:   if (diff<0) {  /* lessen constraints, shift contents of BV */
    278:     for (i=0;i<V->m;i++) {
    279:       PetscCall(BVGetColumn(V,i,&x));
    280:       PetscCall(BVGetColumn(V,i+diff,&y));
    281:       PetscCall(VecCopy(x,y));
    282:       PetscCall(BVRestoreColumn(V,i,&x));
    283:       PetscCall(BVRestoreColumn(V,i+diff,&y));
    284:     }
    285:   }
    286:   V->nc = nc;
    287:   V->ci[0] = -V->nc-1;
    288:   V->ci[1] = -V->nc-1;
    289:   V->m = total-nc;
    290:   V->l = PetscMin(V->l,V->m);
    291:   V->k = PetscMin(V->k,V->m);
    292:   PetscCall(PetscObjectStateIncrease((PetscObject)V));
    293:   PetscFunctionReturn(PETSC_SUCCESS);
    294: }

    296: /*@
    297:    BVGetNumConstraints - Returns the number of constraints.

    299:    Not Collective

    301:    Input Parameter:
    302: .  bv - the basis vectors

    304:    Output Parameters:
    305: .  nc - the number of constraints

    307:    Level: advanced

    309: .seealso: BVGetSizes(), BVInsertConstraints()
    310: @*/
    311: PetscErrorCode BVGetNumConstraints(BV bv,PetscInt *nc)
    312: {
    313:   PetscFunctionBegin;
    315:   PetscAssertPointer(nc,2);
    316:   *nc = bv->nc;
    317:   PetscFunctionReturn(PETSC_SUCCESS);
    318: }

    320: /*@
    321:    BVResize - Change the number of columns.

    323:    Collective

    325:    Input Parameters:
    326: +  bv   - the basis vectors
    327: .  m    - the new number of columns
    328: -  copy - a flag indicating whether current values should be kept

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

    334:    Level: advanced

    336: .seealso: BVSetSizes(), BVSetSizesFromVec()
    337: @*/
    338: PetscErrorCode BVResize(BV bv,PetscInt m,PetscBool copy)
    339: {
    340:   PetscScalar       *array;
    341:   const PetscScalar *omega;
    342:   Vec               v;

    344:   PetscFunctionBegin;
    349:   PetscCheck(m>0,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Number of columns %" PetscInt_FMT " must be positive",m);
    350:   PetscCheck(!bv->nc || bv->issplit,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Cannot resize a BV with constraints");
    351:   if (bv->m == m) PetscFunctionReturn(PETSC_SUCCESS);
    352:   BVCheckOp(bv,1,resize);

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

    385: /*@
    386:    BVSetActiveColumns - Specify the columns that will be involved in operations.

    388:    Logically Collective

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

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

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

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

    408:    Level: intermediate

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

    434: /*@
    435:    BVGetActiveColumns - Returns the current active dimensions.

    437:    Not Collective

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

    442:    Output Parameters:
    443: +  l  - number of leading columns
    444: -  k  - number of active columns

    446:    Level: intermediate

    448: .seealso: BVSetActiveColumns()
    449: @*/
    450: PetscErrorCode BVGetActiveColumns(BV bv,PetscInt *l,PetscInt *k)
    451: {
    452:   PetscFunctionBegin;
    454:   if (l) *l = bv->l;
    455:   if (k) *k = bv->k;
    456:   PetscFunctionReturn(PETSC_SUCCESS);
    457: }

    459: /*@
    460:    BVSetMatrix - Specifies the inner product to be used in orthogonalization.

    462:    Collective

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

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

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

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

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

    484:    Level: advanced

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

    492:   PetscFunctionBegin;
    495:   if (B!=bv->matrix || (B && ((PetscObject)B)->id!=((PetscObject)bv->matrix)->id) || indef!=bv->indef) {
    496:     if (B) {
    498:       PetscCall(MatGetLocalSize(B,&m,&n));
    499:       PetscCheck(m==n,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_SIZ,"Matrix must be square");
    500:       PetscCheck(!bv->m || bv->n==n,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_INCOMP,"Mismatching local dimension BV %" PetscInt_FMT ", Mat %" PetscInt_FMT,bv->n,n);
    501:     }
    502:     if (B) PetscCall(PetscObjectReference((PetscObject)B));
    503:     PetscCall(MatDestroy(&bv->matrix));
    504:     bv->matrix = B;
    505:     bv->indef  = indef;
    506:     PetscCall(PetscObjectStateIncrease((PetscObject)bv));
    507:     if (bv->Bx) PetscCall(PetscObjectStateIncrease((PetscObject)bv->Bx));
    508:     if (bv->cached) PetscCall(PetscObjectStateIncrease((PetscObject)bv->cached));
    509:   }
    510:   PetscFunctionReturn(PETSC_SUCCESS);
    511: }

    513: /*@
    514:    BVGetMatrix - Retrieves the matrix representation of the inner product.

    516:    Not Collective

    518:    Input Parameter:
    519: .  bv    - the basis vectors context

    521:    Output Parameters:
    522: +  B     - the matrix of the inner product (may be NULL)
    523: -  indef - the flag indicating if the matrix is indefinite

    525:    Level: advanced

    527: .seealso: BVSetMatrix()
    528: @*/
    529: PetscErrorCode BVGetMatrix(BV bv,Mat *B,PetscBool *indef)
    530: {
    531:   PetscFunctionBegin;
    533:   if (B)     *B     = bv->matrix;
    534:   if (indef) *indef = bv->indef;
    535:   PetscFunctionReturn(PETSC_SUCCESS);
    536: }

    538: /*@
    539:    BVApplyMatrix - Multiplies a vector by the matrix representation of the
    540:    inner product.

    542:    Neighbor-wise Collective

    544:    Input Parameters:
    545: +  bv - the basis vectors context
    546: -  x  - the vector

    548:    Output Parameter:
    549: .  y  - the result

    551:    Note:
    552:    If no matrix was specified this function copies the vector.

    554:    Level: advanced

    556: .seealso: BVSetMatrix(), BVApplyMatrixBV()
    557: @*/
    558: PetscErrorCode BVApplyMatrix(BV bv,Vec x,Vec y)
    559: {
    560:   PetscFunctionBegin;
    564:   if (bv->matrix) {
    565:     PetscCall(BV_IPMatMult(bv,x));
    566:     PetscCall(VecCopy(bv->Bx,y));
    567:   } else PetscCall(VecCopy(x,y));
    568:   PetscFunctionReturn(PETSC_SUCCESS);
    569: }

    571: /*@
    572:    BVApplyMatrixBV - Multiplies the BV vectors by the matrix representation
    573:    of the inner product.

    575:    Neighbor-wise Collective

    577:    Input Parameter:
    578: .  X - the basis vectors context

    580:    Output Parameter:
    581: .  Y - the basis vectors to store the result (optional)

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

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

    590:    Level: developer

    592: .seealso: BVSetMatrix(), BVApplyMatrix(), BVMatMult(), BVGetCachedBV()
    593: @*/
    594: PetscErrorCode BVApplyMatrixBV(BV X,BV Y)
    595: {
    596:   PetscFunctionBegin;
    598:   if (Y) {
    600:     if (X->matrix) PetscCall(BVMatMult(X,X->matrix,Y));
    601:     else PetscCall(BVCopy(X,Y));
    602:   } else PetscCall(BV_IPMatMultBV(X));
    603:   PetscFunctionReturn(PETSC_SUCCESS);
    604: }

    606: /*@
    607:    BVSetSignature - Sets the signature matrix to be used in orthogonalization.

    609:    Logically Collective

    611:    Input Parameters:
    612: +  bv    - the basis vectors context
    613: -  omega - a vector representing the diagonal of the signature matrix

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

    618:    Level: developer

    620: .seealso: BVSetMatrix(), BVGetSignature()
    621: @*/
    622: PetscErrorCode BVSetSignature(BV bv,Vec omega)
    623: {
    624:   PetscInt          i,n;
    625:   const PetscScalar *pomega;
    626:   PetscScalar       *intern;

    628:   PetscFunctionBegin;
    630:   BVCheckSizes(bv,1);

    634:   PetscCall(VecGetSize(omega,&n));
    635:   PetscCheck(n==bv->k,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_SIZ,"Vec argument has %" PetscInt_FMT " elements, should be %" PetscInt_FMT,n,bv->k);
    636:   PetscCall(BV_AllocateSignature(bv));
    637:   if (bv->indef) {
    638:     PetscCall(VecGetArrayRead(omega,&pomega));
    639:     PetscCall(VecGetArray(bv->omega,&intern));
    640:     for (i=0;i<n;i++) intern[bv->nc+i] = pomega[i];
    641:     PetscCall(VecRestoreArray(bv->omega,&intern));
    642:     PetscCall(VecRestoreArrayRead(omega,&pomega));
    643:   } else PetscCall(PetscInfo(bv,"Ignoring signature because BV is not indefinite\n"));
    644:   PetscCall(PetscObjectStateIncrease((PetscObject)bv));
    645:   PetscFunctionReturn(PETSC_SUCCESS);
    646: }

    648: /*@
    649:    BVGetSignature - Retrieves the signature matrix from last orthogonalization.

    651:    Not Collective

    653:    Input Parameter:
    654: .  bv    - the basis vectors context

    656:    Output Parameter:
    657: .  omega - a vector representing the diagonal of the signature matrix

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

    662:    Level: developer

    664: .seealso: BVSetMatrix(), BVSetSignature()
    665: @*/
    666: PetscErrorCode BVGetSignature(BV bv,Vec omega)
    667: {
    668:   PetscInt          i,n;
    669:   PetscScalar       *pomega;
    670:   const PetscScalar *intern;

    672:   PetscFunctionBegin;
    674:   BVCheckSizes(bv,1);

    678:   PetscCall(VecGetSize(omega,&n));
    679:   PetscCheck(n==bv->k,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_SIZ,"Vec argument has %" PetscInt_FMT " elements, should be %" PetscInt_FMT,n,bv->k);
    680:   if (bv->indef && bv->omega) {
    681:     PetscCall(VecGetArray(omega,&pomega));
    682:     PetscCall(VecGetArrayRead(bv->omega,&intern));
    683:     for (i=0;i<n;i++) pomega[i] = intern[bv->nc+i];
    684:     PetscCall(VecRestoreArrayRead(bv->omega,&intern));
    685:     PetscCall(VecRestoreArray(omega,&pomega));
    686:   } else PetscCall(VecSet(omega,1.0));
    687:   PetscFunctionReturn(PETSC_SUCCESS);
    688: }

    690: /*@
    691:    BVSetBufferVec - Attach a vector object to be used as buffer space for
    692:    several operations.

    694:    Collective

    696:    Input Parameters:
    697: +  bv     - the basis vectors context)
    698: -  buffer - the vector

    700:    Notes:
    701:    Use BVGetBufferVec() to retrieve the vector (for example, to free it
    702:    at the end of the computations).

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

    707:    Level: developer

    709: .seealso: BVGetBufferVec(), BVSetSizes(), BVGetNumConstraints()
    710: @*/
    711: PetscErrorCode BVSetBufferVec(BV bv,Vec buffer)
    712: {
    713:   PetscInt       ld,n;
    714:   PetscMPIInt    size;

    716:   PetscFunctionBegin;
    719:   BVCheckSizes(bv,1);
    720:   PetscCall(VecGetSize(buffer,&n));
    721:   ld = bv->m+bv->nc;
    722:   PetscCheck(n==ld*bv->m,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_SIZ,"Buffer size must be %" PetscInt_FMT,ld*bv->m);
    723:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)buffer),&size));
    724:   PetscCheck(size==1,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Buffer must be a sequential vector");

    726:   PetscCall(PetscObjectReference((PetscObject)buffer));
    727:   PetscCall(VecDestroy(&bv->buffer));
    728:   bv->buffer = buffer;
    729:   PetscFunctionReturn(PETSC_SUCCESS);
    730: }

    732: /*@
    733:    BVGetBufferVec - Obtain the buffer vector associated with the BV object.

    735:    Collective

    737:    Input Parameters:
    738: .  bv - the basis vectors context

    740:    Output Parameter:
    741: .  buffer - vector

    743:    Notes:
    744:    The vector is created if not available previously. It is a sequential vector
    745:    of length (nc+m)*m, where m is the number of columns of bv and nc is the number
    746:    of constraints.

    748:    Developer Notes:
    749:    The buffer vector is viewed as a column-major matrix with leading dimension
    750:    ld=nc+m, and m columns at most. In the most common usage, it has the structure
    751: .vb
    752:       | | C |
    753:       |s|---|
    754:       | | H |
    755: .ve
    756:    where H is an upper Hessenberg matrix of order m x (m-1), C contains coefficients
    757:    related to orthogonalization against constraints (first nc rows), and s is the
    758:    first column that contains scratch values computed during Gram-Schmidt
    759:    orthogonalization. In particular, BVDotColumn() and BVMultColumn() use s to
    760:    store the coefficients.

    762:    Level: developer

    764: .seealso: BVSetBufferVec(), BVSetSizes(), BVGetNumConstraints(), BVDotColumn(), BVMultColumn()
    765: @*/
    766: PetscErrorCode BVGetBufferVec(BV bv,Vec *buffer)
    767: {
    768:   PetscInt       ld;

    770:   PetscFunctionBegin;
    772:   PetscAssertPointer(buffer,2);
    773:   BVCheckSizes(bv,1);
    774:   if (!bv->buffer) {
    775:     ld = bv->m+bv->nc;
    776:     PetscCall(VecCreate(PETSC_COMM_SELF,&bv->buffer));
    777:     PetscCall(VecSetSizes(bv->buffer,PETSC_DECIDE,ld*bv->m));
    778:     PetscCall(VecSetType(bv->buffer,bv->vtype));
    779:   }
    780:   *buffer = bv->buffer;
    781:   PetscFunctionReturn(PETSC_SUCCESS);
    782: }

    784: /*@
    785:    BVSetRandomContext - Sets the PetscRandom object associated with the BV,
    786:    to be used in operations that need random numbers.

    788:    Collective

    790:    Input Parameters:
    791: +  bv   - the basis vectors context
    792: -  rand - the random number generator context

    794:    Level: advanced

    796: .seealso: BVGetRandomContext(), BVSetRandom(), BVSetRandomNormal(), BVSetRandomColumn(), BVSetRandomCond()
    797: @*/
    798: PetscErrorCode BVSetRandomContext(BV bv,PetscRandom rand)
    799: {
    800:   PetscFunctionBegin;
    803:   PetscCheckSameComm(bv,1,rand,2);
    804:   PetscCall(PetscObjectReference((PetscObject)rand));
    805:   PetscCall(PetscRandomDestroy(&bv->rand));
    806:   bv->rand = rand;
    807:   PetscFunctionReturn(PETSC_SUCCESS);
    808: }

    810: /*@
    811:    BVGetRandomContext - Gets the PetscRandom object associated with the BV.

    813:    Collective

    815:    Input Parameter:
    816: .  bv - the basis vectors context

    818:    Output Parameter:
    819: .  rand - the random number generator context

    821:    Level: advanced

    823: .seealso: BVSetRandomContext(), BVSetRandom(), BVSetRandomNormal(), BVSetRandomColumn(), BVSetRandomCond()
    824: @*/
    825: PetscErrorCode BVGetRandomContext(BV bv,PetscRandom* rand)
    826: {
    827:   PetscFunctionBegin;
    829:   PetscAssertPointer(rand,2);
    830:   if (!bv->rand) {
    831:     PetscCall(PetscRandomCreate(PetscObjectComm((PetscObject)bv),&bv->rand));
    832:     if (bv->cuda) PetscCall(PetscRandomSetType(bv->rand,PETSCCURAND));
    833:     if (bv->sfocalled) PetscCall(PetscRandomSetFromOptions(bv->rand));
    834:     if (bv->rrandom) {
    835:       PetscCall(PetscRandomSetSeed(bv->rand,0x12345678));
    836:       PetscCall(PetscRandomSeed(bv->rand));
    837:     }
    838:   }
    839:   *rand = bv->rand;
    840:   PetscFunctionReturn(PETSC_SUCCESS);
    841: }

    843: /*@
    844:    BVSetFromOptions - Sets BV options from the options database.

    846:    Collective

    848:    Input Parameter:
    849: .  bv - the basis vectors context

    851:    Level: beginner

    853: .seealso: BVSetOptionsPrefix()
    854: @*/
    855: PetscErrorCode BVSetFromOptions(BV bv)
    856: {
    857:   char               type[256];
    858:   PetscBool          flg1,flg2,flg3,flg4;
    859:   PetscReal          r;
    860:   BVOrthogType       otype;
    861:   BVOrthogRefineType orefine;
    862:   BVOrthogBlockType  oblock;

    864:   PetscFunctionBegin;
    866:   PetscCall(BVRegisterAll());
    867:   PetscObjectOptionsBegin((PetscObject)bv);
    868:     PetscCall(PetscOptionsFList("-bv_type","Basis Vectors type","BVSetType",BVList,(char*)(((PetscObject)bv)->type_name?((PetscObject)bv)->type_name:BVMAT),type,sizeof(type),&flg1));
    869:     if (flg1) PetscCall(BVSetType(bv,type));
    870:     else if (!((PetscObject)bv)->type_name) PetscCall(BVSetType(bv,BVMAT));

    872:     otype = bv->orthog_type;
    873:     PetscCall(PetscOptionsEnum("-bv_orthog_type","Orthogonalization method","BVSetOrthogonalization",BVOrthogTypes,(PetscEnum)otype,(PetscEnum*)&otype,&flg1));
    874:     orefine = bv->orthog_ref;
    875:     PetscCall(PetscOptionsEnum("-bv_orthog_refine","Iterative refinement mode during orthogonalization","BVSetOrthogonalization",BVOrthogRefineTypes,(PetscEnum)orefine,(PetscEnum*)&orefine,&flg2));
    876:     r = bv->orthog_eta;
    877:     PetscCall(PetscOptionsReal("-bv_orthog_eta","Parameter of iterative refinement during orthogonalization","BVSetOrthogonalization",r,&r,&flg3));
    878:     oblock = bv->orthog_block;
    879:     PetscCall(PetscOptionsEnum("-bv_orthog_block","Block orthogonalization method","BVSetOrthogonalization",BVOrthogBlockTypes,(PetscEnum)oblock,(PetscEnum*)&oblock,&flg4));
    880:     if (flg1 || flg2 || flg3 || flg4) PetscCall(BVSetOrthogonalization(bv,otype,orefine,r,oblock));

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

    884:     PetscCall(PetscOptionsReal("-bv_definite_tol","Tolerance for checking a definite inner product","BVSetDefiniteTolerance",r,&r,&flg1));
    885:     if (flg1) PetscCall(BVSetDefiniteTolerance(bv,r));

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

    890:     if (bv->ops->create) bv->defersfo = PETSC_TRUE;   /* defer call to setfromoptions */
    891:     else PetscTryTypeMethod(bv,setfromoptions,PetscOptionsObject);
    892:     PetscCall(PetscObjectProcessOptionsHandlers((PetscObject)bv,PetscOptionsObject));
    893:   PetscOptionsEnd();
    894:   bv->sfocalled = PETSC_TRUE;
    895:   PetscFunctionReturn(PETSC_SUCCESS);
    896: }

    898: /*@
    899:    BVSetOrthogonalization - Specifies the method used for the orthogonalization of
    900:    vectors (classical or modified Gram-Schmidt with or without refinement), and
    901:    for the block-orthogonalization (simultaneous orthogonalization of a set of
    902:    vectors).

    904:    Logically Collective

    906:    Input Parameters:
    907: +  bv     - the basis vectors context
    908: .  type   - the method of vector orthogonalization
    909: .  refine - type of refinement
    910: .  eta    - parameter for selective refinement
    911: -  block  - the method of block orthogonalization

    913:    Options Database Keys:
    914: +  -bv_orthog_type <type> - Where <type> is cgs for Classical Gram-Schmidt orthogonalization
    915:                          (default) or mgs for Modified Gram-Schmidt orthogonalization
    916: .  -bv_orthog_refine <ref> - Where <ref> is one of never, ifneeded (default) or always
    917: .  -bv_orthog_eta <eta> -  For setting the value of eta
    918: -  -bv_orthog_block <block> - Where <block> is the block-orthogonalization method

    920:    Notes:
    921:    The default settings work well for most problems.

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

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

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

    931:    Level: advanced

    933: .seealso: BVOrthogonalizeColumn(), BVGetOrthogonalization(), BVOrthogType, BVOrthogRefineType, BVOrthogBlockType
    934: @*/
    935: PetscErrorCode BVSetOrthogonalization(BV bv,BVOrthogType type,BVOrthogRefineType refine,PetscReal eta,BVOrthogBlockType block)
    936: {
    937:   PetscFunctionBegin;
    943:   switch (type) {
    944:     case BV_ORTHOG_CGS:
    945:     case BV_ORTHOG_MGS:
    946:       bv->orthog_type = type;
    947:       break;
    948:     default:
    949:       SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Unknown orthogonalization type");
    950:   }
    951:   switch (refine) {
    952:     case BV_ORTHOG_REFINE_NEVER:
    953:     case BV_ORTHOG_REFINE_IFNEEDED:
    954:     case BV_ORTHOG_REFINE_ALWAYS:
    955:       bv->orthog_ref = refine;
    956:       break;
    957:     default:
    958:       SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Unknown refinement type");
    959:   }
    960:   if (eta == (PetscReal)PETSC_DEFAULT) {
    961:     bv->orthog_eta = 0.7071;
    962:   } else {
    963:     PetscCheck(eta>0.0 && eta<=1.0,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"Invalid eta value");
    964:     bv->orthog_eta = eta;
    965:   }
    966:   switch (block) {
    967:     case BV_ORTHOG_BLOCK_GS:
    968:     case BV_ORTHOG_BLOCK_CHOL:
    969:     case BV_ORTHOG_BLOCK_TSQR:
    970:     case BV_ORTHOG_BLOCK_TSQRCHOL:
    971:     case BV_ORTHOG_BLOCK_SVQB:
    972:       bv->orthog_block = block;
    973:       break;
    974:     default:
    975:       SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Unknown block orthogonalization type");
    976:   }
    977:   PetscFunctionReturn(PETSC_SUCCESS);
    978: }

    980: /*@
    981:    BVGetOrthogonalization - Gets the orthogonalization settings from the BV object.

    983:    Not Collective

    985:    Input Parameter:
    986: .  bv - basis vectors context

    988:    Output Parameters:
    989: +  type   - the method of vector orthogonalization
    990: .  refine - type of refinement
    991: .  eta    - parameter for selective refinement
    992: -  block  - the method of block orthogonalization

    994:    Level: advanced

    996: .seealso: BVOrthogonalizeColumn(), BVSetOrthogonalization(), BVOrthogType, BVOrthogRefineType, BVOrthogBlockType
    997: @*/
    998: PetscErrorCode BVGetOrthogonalization(BV bv,BVOrthogType *type,BVOrthogRefineType *refine,PetscReal *eta,BVOrthogBlockType *block)
    999: {
    1000:   PetscFunctionBegin;
    1002:   if (type)   *type   = bv->orthog_type;
    1003:   if (refine) *refine = bv->orthog_ref;
    1004:   if (eta)    *eta    = bv->orthog_eta;
    1005:   if (block)  *block  = bv->orthog_block;
    1006:   PetscFunctionReturn(PETSC_SUCCESS);
    1007: }

    1009: /*@
    1010:    BVSetMatMultMethod - Specifies the method used for the BVMatMult() operation.

    1012:    Logically Collective

    1014:    Input Parameters:
    1015: +  bv     - the basis vectors context
    1016: -  method - the method for the BVMatMult() operation

    1018:    Options Database Keys:
    1019: .  -bv_matmult <meth> - choose one of the methods: vecs, mat

    1021:    Notes:
    1022:    Allowed values are
    1023: +  BV_MATMULT_VECS - perform a matrix-vector multiply per each column
    1024: .  BV_MATMULT_MAT - carry out a Mat-Mat product with a dense matrix
    1025: -  BV_MATMULT_MAT_SAVE - this case is deprecated

    1027:    The default is BV_MATMULT_MAT except in the case of BVVECS.

    1029:    Level: advanced

    1031: .seealso: BVMatMult(), BVGetMatMultMethod(), BVMatMultType
    1032: @*/
    1033: PetscErrorCode BVSetMatMultMethod(BV bv,BVMatMultType method)
    1034: {
    1035:   PetscFunctionBegin;
    1038:   switch (method) {
    1039:     case BV_MATMULT_VECS:
    1040:     case BV_MATMULT_MAT:
    1041:       bv->vmm = method;
    1042:       break;
    1043:     case BV_MATMULT_MAT_SAVE:
    1044:       PetscCall(PetscInfo(bv,"BV_MATMULT_MAT_SAVE is deprecated, using BV_MATMULT_MAT\n"));
    1045:       bv->vmm = BV_MATMULT_MAT;
    1046:       break;
    1047:     default:
    1048:       SETERRQ(PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Unknown matmult method");
    1049:   }
    1050:   PetscFunctionReturn(PETSC_SUCCESS);
    1051: }

    1053: /*@
    1054:    BVGetMatMultMethod - Gets the method used for the BVMatMult() operation.

    1056:    Not Collective

    1058:    Input Parameter:
    1059: .  bv - basis vectors context

    1061:    Output Parameter:
    1062: .  method - the method for the BVMatMult() operation

    1064:    Level: advanced

    1066: .seealso: BVMatMult(), BVSetMatMultMethod(), BVMatMultType
    1067: @*/
    1068: PetscErrorCode BVGetMatMultMethod(BV bv,BVMatMultType *method)
    1069: {
    1070:   PetscFunctionBegin;
    1072:   PetscAssertPointer(method,2);
    1073:   *method = bv->vmm;
    1074:   PetscFunctionReturn(PETSC_SUCCESS);
    1075: }

    1077: /*@
    1078:    BVGetColumn - Returns a Vec object that contains the entries of the
    1079:    requested column of the basis vectors object.

    1081:    Logically Collective

    1083:    Input Parameters:
    1084: +  bv - the basis vectors context
    1085: -  j  - the index of the requested column

    1087:    Output Parameter:
    1088: .  v  - vector containing the jth column

    1090:    Notes:
    1091:    The returned Vec must be seen as a reference (not a copy) of the BV
    1092:    column, that is, modifying the Vec will change the BV entries as well.

    1094:    The returned Vec must not be destroyed. BVRestoreColumn() must be
    1095:    called when it is no longer needed. At most, two columns can be fetched,
    1096:    that is, this function can only be called twice before the corresponding
    1097:    BVRestoreColumn() is invoked.

    1099:    A negative index j selects the i-th constraint, where i=-j. Constraints
    1100:    should not be modified.

    1102:    Level: beginner

    1104: .seealso: BVRestoreColumn(), BVInsertConstraints()
    1105: @*/
    1106: PetscErrorCode BVGetColumn(BV bv,PetscInt j,Vec *v)
    1107: {
    1108:   PetscInt       l;

    1110:   PetscFunctionBegin;
    1113:   BVCheckSizes(bv,1);
    1114:   BVCheckOp(bv,1,getcolumn);
    1116:   PetscCheck(j>=0 || -j<=bv->nc,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"You requested constraint %" PetscInt_FMT " but only %" PetscInt_FMT " are available",-j,bv->nc);
    1117:   PetscCheck(j<bv->m,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"You requested column %" PetscInt_FMT " but only %" PetscInt_FMT " are available",j,bv->m);
    1118:   PetscCheck(j!=bv->ci[0] && j!=bv->ci[1],PetscObjectComm((PetscObject)bv),PETSC_ERR_SUP,"Column %" PetscInt_FMT " already fetched in a previous call to BVGetColumn",j);
    1119:   l = BVAvailableVec;
    1120:   PetscCheck(l!=-1,PetscObjectComm((PetscObject)bv),PETSC_ERR_SUP,"Too many requested columns; you must call BVRestoreColumn for one of the previously fetched columns");
    1121:   PetscUseTypeMethod(bv,getcolumn,j,v);
    1122:   bv->ci[l] = j;
    1123:   PetscCall(PetscObjectStateGet((PetscObject)bv->cv[l],&bv->st[l]));
    1124:   PetscCall(PetscObjectGetId((PetscObject)bv->cv[l],&bv->id[l]));
    1125:   *v = bv->cv[l];
    1126:   PetscFunctionReturn(PETSC_SUCCESS);
    1127: }

    1129: /*@
    1130:    BVRestoreColumn - Restore a column obtained with BVGetColumn().

    1132:    Logically Collective

    1134:    Input Parameters:
    1135: +  bv - the basis vectors context
    1136: .  j  - the index of the column
    1137: -  v  - vector obtained with BVGetColumn()

    1139:    Note:
    1140:    The arguments must match the corresponding call to BVGetColumn().

    1142:    Level: beginner

    1144: .seealso: BVGetColumn()
    1145: @*/
    1146: PetscErrorCode BVRestoreColumn(BV bv,PetscInt j,Vec *v)
    1147: {
    1148:   PetscObjectId    id;
    1149:   PetscObjectState st;
    1150:   PetscInt         l;

    1152:   PetscFunctionBegin;
    1155:   BVCheckSizes(bv,1);
    1157:   PetscAssertPointer(v,3);
    1159:   PetscCheck(j>=0 || -j<=bv->nc,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"You requested constraint %" PetscInt_FMT " but only %" PetscInt_FMT " are available",-j,bv->nc);
    1160:   PetscCheck(j<bv->m,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"You requested column %" PetscInt_FMT " but only %" PetscInt_FMT " are available",j,bv->m);
    1161:   PetscCheck(j==bv->ci[0] || j==bv->ci[1],PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Column %" PetscInt_FMT " has not been fetched with a call to BVGetColumn",j);
    1162:   l = (j==bv->ci[0])? 0: 1;
    1163:   PetscCall(PetscObjectGetId((PetscObject)*v,&id));
    1164:   PetscCheck(id==bv->id[l],PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Argument 3 is not the same Vec that was obtained with BVGetColumn");
    1165:   PetscCall(PetscObjectStateGet((PetscObject)*v,&st));
    1166:   if (st!=bv->st[l]) PetscCall(PetscObjectStateIncrease((PetscObject)bv));
    1167:   PetscUseTypeMethod(bv,restorecolumn,j,v);
    1168:   bv->ci[l] = -bv->nc-1;
    1169:   bv->st[l] = -1;
    1170:   bv->id[l] = 0;
    1171:   *v = NULL;
    1172:   PetscFunctionReturn(PETSC_SUCCESS);
    1173: }

    1175: /*@C
    1176:    BVGetArray - Returns a pointer to a contiguous array that contains this
    1177:    processor's portion of the BV data.

    1179:    Logically Collective

    1181:    Input Parameters:
    1182: .  bv - the basis vectors context

    1184:    Output Parameter:
    1185: .  a  - location to put pointer to the array

    1187:    Notes:
    1188:    BVRestoreArray() must be called when access to the array is no longer needed.
    1189:    This operation may imply a data copy, for BV types that do not store
    1190:    data contiguously in memory.

    1192:    The pointer will normally point to the first entry of the first column,
    1193:    but if the BV has constraints then these go before the regular columns.

    1195:    Note that for manipulating the pointer to the BV array, one must take into
    1196:    account the leading dimension, which might be different from the local
    1197:    number of rows, see BVGetLeadingDimension().

    1199:    Use BVGetArrayRead() for read-only access.

    1201:    Level: advanced

    1203: .seealso: BVRestoreArray(), BVInsertConstraints(), BVGetLeadingDimension(), BVGetArrayRead()
    1204: @*/
    1205: PetscErrorCode BVGetArray(BV bv,PetscScalar **a)
    1206: {
    1207:   PetscFunctionBegin;
    1210:   BVCheckSizes(bv,1);
    1211:   BVCheckOp(bv,1,getarray);
    1212:   PetscUseTypeMethod(bv,getarray,a);
    1213:   PetscFunctionReturn(PETSC_SUCCESS);
    1214: }

    1216: /*@C
    1217:    BVRestoreArray - Restore the BV object after BVGetArray() has been called.

    1219:    Logically Collective

    1221:    Input Parameters:
    1222: +  bv - the basis vectors context
    1223: -  a  - location of pointer to array obtained from BVGetArray()

    1225:    Note:
    1226:    This operation may imply a data copy, for BV types that do not store
    1227:    data contiguously in memory.

    1229:    Level: advanced

    1231: .seealso: BVGetColumn()
    1232: @*/
    1233: PetscErrorCode BVRestoreArray(BV bv,PetscScalar **a)
    1234: {
    1235:   PetscFunctionBegin;
    1238:   BVCheckSizes(bv,1);
    1239:   PetscTryTypeMethod(bv,restorearray,a);
    1240:   if (a) *a = NULL;
    1241:   PetscCall(PetscObjectStateIncrease((PetscObject)bv));
    1242:   PetscFunctionReturn(PETSC_SUCCESS);
    1243: }

    1245: /*@C
    1246:    BVGetArrayRead - Returns a read-only pointer to a contiguous array that
    1247:    contains this processor's portion of the BV data.

    1249:    Not Collective

    1251:    Input Parameters:
    1252: .  bv - the basis vectors context

    1254:    Output Parameter:
    1255: .  a  - location to put pointer to the array

    1257:    Notes:
    1258:    BVRestoreArrayRead() must be called when access to the array is no
    1259:    longer needed. This operation may imply a data copy, for BV types that
    1260:    do not store data contiguously in memory.

    1262:    The pointer will normally point to the first entry of the first column,
    1263:    but if the BV has constraints then these go before the regular columns.

    1265:    Level: advanced

    1267: .seealso: BVRestoreArray(), BVInsertConstraints(), BVGetLeadingDimension(), BVGetArray()
    1268: @*/
    1269: PetscErrorCode BVGetArrayRead(BV bv,const PetscScalar **a)
    1270: {
    1271:   PetscFunctionBegin;
    1274:   BVCheckSizes(bv,1);
    1275:   BVCheckOp(bv,1,getarrayread);
    1276:   PetscUseTypeMethod(bv,getarrayread,a);
    1277:   PetscFunctionReturn(PETSC_SUCCESS);
    1278: }

    1280: /*@C
    1281:    BVRestoreArrayRead - Restore the BV object after BVGetArrayRead() has
    1282:    been called.

    1284:    Not Collective

    1286:    Input Parameters:
    1287: +  bv - the basis vectors context
    1288: -  a  - location of pointer to array obtained from BVGetArrayRead()

    1290:    Level: advanced

    1292: .seealso: BVGetColumn()
    1293: @*/
    1294: PetscErrorCode BVRestoreArrayRead(BV bv,const PetscScalar **a)
    1295: {
    1296:   PetscFunctionBegin;
    1299:   BVCheckSizes(bv,1);
    1300:   PetscTryTypeMethod(bv,restorearrayread,a);
    1301:   if (a) *a = NULL;
    1302:   PetscFunctionReturn(PETSC_SUCCESS);
    1303: }

    1305: /*@
    1306:    BVCreateVec - Creates a new Vec object with the same type and dimensions
    1307:    as the columns of the basis vectors object.

    1309:    Collective

    1311:    Input Parameter:
    1312: .  bv - the basis vectors context

    1314:    Output Parameter:
    1315: .  v  - the new vector

    1317:    Note:
    1318:    The user is responsible of destroying the returned vector.

    1320:    Level: beginner

    1322: .seealso: BVCreateMat(), BVCreateVecEmpty()
    1323: @*/
    1324: PetscErrorCode BVCreateVec(BV bv,Vec *v)
    1325: {
    1326:   PetscFunctionBegin;
    1328:   BVCheckSizes(bv,1);
    1329:   PetscAssertPointer(v,2);
    1330:   PetscCall(VecCreate(PetscObjectComm((PetscObject)bv),v));
    1331:   PetscCall(VecSetLayout(*v,bv->map));
    1332:   PetscCall(VecSetType(*v,bv->vtype));
    1333:   PetscCall(VecSetUp(*v));
    1334:   PetscFunctionReturn(PETSC_SUCCESS);
    1335: }

    1337: /*@
    1338:    BVCreateVecEmpty - Creates a new Vec object with the same type and dimensions
    1339:    as the columns of the basis vectors object, but without internal array.

    1341:    Collective

    1343:    Input Parameter:
    1344: .  bv - the basis vectors context

    1346:    Output Parameter:
    1347: .  v  - the new vector

    1349:    Note:
    1350:    This works as BVCreateVec(), but the new vector does not have the array allocated,
    1351:    so the intended usage is with VecPlaceArray().

    1353:    Level: developer

    1355: .seealso: BVCreateVec()
    1356: @*/
    1357: PetscErrorCode BVCreateVecEmpty(BV bv,Vec *v)
    1358: {
    1359:   PetscBool  standard,cuda,mpi;
    1360:   PetscInt   N,nloc,bs;

    1362:   PetscFunctionBegin;
    1364:   BVCheckSizes(bv,1);
    1365:   PetscAssertPointer(v,2);

    1367:   PetscCall(PetscStrcmpAny(bv->vtype,&standard,VECSEQ,VECMPI,""));
    1368:   PetscCall(PetscStrcmpAny(bv->vtype,&cuda,VECSEQCUDA,VECMPICUDA,""));
    1369:   if (standard || cuda) {
    1370:     PetscCall(PetscStrcmpAny(bv->vtype,&mpi,VECMPI,VECMPICUDA,""));
    1371:     PetscCall(PetscLayoutGetLocalSize(bv->map,&nloc));
    1372:     PetscCall(PetscLayoutGetSize(bv->map,&N));
    1373:     PetscCall(PetscLayoutGetBlockSize(bv->map,&bs));
    1374:     if (cuda) {
    1375: #if defined(PETSC_HAVE_CUDA)
    1376:       if (mpi) PetscCall(VecCreateMPICUDAWithArray(PetscObjectComm((PetscObject)bv),bs,nloc,N,NULL,v));
    1377:       else PetscCall(VecCreateSeqCUDAWithArray(PetscObjectComm((PetscObject)bv),bs,N,NULL,v));
    1378: #endif
    1379:     } else {
    1380:       if (mpi) PetscCall(VecCreateMPIWithArray(PetscObjectComm((PetscObject)bv),bs,nloc,N,NULL,v));
    1381:       else PetscCall(VecCreateSeqWithArray(PetscObjectComm((PetscObject)bv),bs,N,NULL,v));
    1382:     }
    1383:   } else PetscCall(BVCreateVec(bv,v)); /* standard duplicate, with internal array */
    1384:   PetscFunctionReturn(PETSC_SUCCESS);
    1385: }

    1387: /*@C
    1388:    BVSetVecType - Set the vector type to be used when creating vectors via BVCreateVec().

    1390:    Collective

    1392:    Input Parameters:
    1393: +  bv - the basis vectors context
    1394: -  vtype - the vector type

    1396:    Level: advanced

    1398:    Note:
    1399:    This is not needed if the BV object is set up with BVSetSizesFromVec(), but may be
    1400:    required in the case of BVSetSizes() if one wants to work with non-standard vectors.

    1402: .seealso: BVGetVecType(), BVSetSizesFromVec(), BVSetSizes()
    1403: @*/
    1404: PetscErrorCode BVSetVecType(BV bv,VecType vtype)
    1405: {
    1406:   PetscBool   std;
    1407:   PetscMPIInt size;

    1409:   PetscFunctionBegin;
    1411:   PetscCall(PetscFree(bv->vtype));
    1412:   PetscCall(PetscStrcmp(vtype,VECSTANDARD,&std));
    1413:   if (std) {
    1414:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)bv),&size));
    1415:     PetscCall(PetscStrallocpy((size==1)?VECSEQ:VECMPI,(char**)&bv->vtype));
    1416:   } else PetscCall(PetscStrallocpy(vtype,(char**)&bv->vtype));
    1417:   PetscFunctionReturn(PETSC_SUCCESS);
    1418: }

    1420: /*@C
    1421:    BVGetVecType - Get the vector type to be used when creating vectors via BVCreateVec().

    1423:    Not Collective

    1425:    Input Parameter:
    1426: .  bv - the basis vectors context

    1428:    Output Parameter:
    1429: .  vtype - the vector type

    1431:    Level: advanced

    1433: .seealso: BVSetVecType()
    1434: @*/
    1435: PetscErrorCode BVGetVecType(BV bv,VecType *vtype)
    1436: {
    1437:   PetscFunctionBegin;
    1439:   PetscAssertPointer(vtype,2);
    1440:   *vtype = bv->vtype;
    1441:   PetscFunctionReturn(PETSC_SUCCESS);
    1442: }

    1444: /*@
    1445:    BVCreateMat - Creates a new Mat object of dense type and copies the contents
    1446:    of the BV object.

    1448:    Collective

    1450:    Input Parameter:
    1451: .  bv - the basis vectors context

    1453:    Output Parameter:
    1454: .  A  - the new matrix

    1456:    Notes:
    1457:    The user is responsible of destroying the returned matrix.

    1459:    The matrix contains all columns of the BV, not just the active columns.

    1461:    Level: intermediate

    1463: .seealso: BVCreateFromMat(), BVCreateVec(), BVGetMat()
    1464: @*/
    1465: PetscErrorCode BVCreateMat(BV bv,Mat *A)
    1466: {
    1467:   PetscInt ksave,lsave;
    1468:   Mat      B;

    1470:   PetscFunctionBegin;
    1472:   BVCheckSizes(bv,1);
    1473:   PetscAssertPointer(A,2);

    1475:   PetscCall(MatCreateDenseFromVecType(PetscObjectComm((PetscObject)bv),bv->vtype,bv->n,PETSC_DECIDE,bv->N,bv->m,bv->ld,NULL,A));
    1476:   lsave = bv->l;
    1477:   ksave = bv->k;
    1478:   bv->l = 0;
    1479:   bv->k = bv->m;
    1480:   PetscCall(BVGetMat(bv,&B));
    1481:   PetscCall(MatCopy(B,*A,SAME_NONZERO_PATTERN));
    1482:   PetscCall(BVRestoreMat(bv,&B));
    1483:   bv->l = lsave;
    1484:   bv->k = ksave;
    1485:   PetscFunctionReturn(PETSC_SUCCESS);
    1486: }

    1488: PetscErrorCode BVGetMat_Default(BV bv,Mat *A)
    1489: {
    1490:   PetscScalar *vv,*aa;
    1491:   PetscBool   create=PETSC_FALSE;
    1492:   PetscInt    m,cols;

    1494:   PetscFunctionBegin;
    1495:   m = bv->k-bv->l;
    1496:   if (!bv->Aget) create=PETSC_TRUE;
    1497:   else {
    1498:     PetscCall(MatDenseGetArray(bv->Aget,&aa));
    1499:     PetscCheck(!aa,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"BVGetMat already called on this BV");
    1500:     PetscCall(MatGetSize(bv->Aget,NULL,&cols));
    1501:     if (cols!=m) {
    1502:       PetscCall(MatDestroy(&bv->Aget));
    1503:       create=PETSC_TRUE;
    1504:     }
    1505:   }
    1506:   PetscCall(BVGetArray(bv,&vv));
    1507:   if (create) {
    1508:     PetscCall(MatCreateDenseFromVecType(PetscObjectComm((PetscObject)bv),bv->vtype,bv->n,PETSC_DECIDE,bv->N,m,bv->ld,vv,&bv->Aget)); /* pass a pointer to avoid allocation of storage */
    1509:     PetscCall(MatDenseReplaceArray(bv->Aget,NULL));  /* replace with a null pointer, the value after BVRestoreMat */
    1510:   }
    1511:   PetscCall(MatDensePlaceArray(bv->Aget,vv+(bv->nc+bv->l)*bv->ld));  /* set the actual pointer */
    1512:   *A = bv->Aget;
    1513:   PetscFunctionReturn(PETSC_SUCCESS);
    1514: }

    1516: /*@
    1517:    BVGetMat - Returns a Mat object of dense type that shares the memory of
    1518:    the BV object.

    1520:    Collective

    1522:    Input Parameter:
    1523: .  bv - the basis vectors context

    1525:    Output Parameter:
    1526: .  A  - the matrix

    1528:    Notes:
    1529:    The returned matrix contains only the active columns. If the content of
    1530:    the Mat is modified, these changes are also done in the BV object. The
    1531:    user must call BVRestoreMat() when no longer needed.

    1533:    This operation implies a call to BVGetArray(), which may result in data
    1534:    copies.

    1536:    Level: advanced

    1538: .seealso: BVRestoreMat(), BVCreateMat(), BVGetArray()
    1539: @*/
    1540: PetscErrorCode BVGetMat(BV bv,Mat *A)
    1541: {
    1542:   PetscFunctionBegin;
    1544:   BVCheckSizes(bv,1);
    1545:   PetscAssertPointer(A,2);
    1546:   PetscUseTypeMethod(bv,getmat,A);
    1547:   PetscFunctionReturn(PETSC_SUCCESS);
    1548: }

    1550: PetscErrorCode BVRestoreMat_Default(BV bv,Mat *A)
    1551: {
    1552:   PetscScalar *vv,*aa;

    1554:   PetscFunctionBegin;
    1555:   PetscCall(MatDenseGetArray(bv->Aget,&aa));
    1556:   vv = aa-(bv->nc+bv->l)*bv->ld;
    1557:   PetscCall(MatDenseResetArray(bv->Aget));
    1558:   PetscCall(BVRestoreArray(bv,&vv));
    1559:   *A = NULL;
    1560:   PetscFunctionReturn(PETSC_SUCCESS);
    1561: }

    1563: /*@
    1564:    BVRestoreMat - Restores the Mat obtained with BVGetMat().

    1566:    Logically Collective

    1568:    Input Parameters:
    1569: +  bv - the basis vectors context
    1570: -  A  - the fetched matrix

    1572:    Note:
    1573:    A call to this function must match a previous call of BVGetMat().
    1574:    The effect is that the contents of the Mat are copied back to the
    1575:    BV internal data structures.

    1577:    Level: advanced

    1579: .seealso: BVGetMat(), BVRestoreArray()
    1580: @*/
    1581: PetscErrorCode BVRestoreMat(BV bv,Mat *A)
    1582: {
    1583:   PetscFunctionBegin;
    1585:   BVCheckSizes(bv,1);
    1586:   PetscAssertPointer(A,2);
    1587:   PetscCheck(bv->Aget,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"BVRestoreMat must match a previous call to BVGetMat");
    1588:   PetscCheck(bv->Aget==*A,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Mat argument is not the same as the one obtained with BVGetMat");
    1589:   PetscUseTypeMethod(bv,restoremat,A);
    1590:   PetscFunctionReturn(PETSC_SUCCESS);
    1591: }

    1593: /*
    1594:    Copy all user-provided attributes of V to another BV object W
    1595:  */
    1596: static inline PetscErrorCode BVDuplicate_Private(BV V,BV W)
    1597: {
    1598:   PetscFunctionBegin;
    1599:   PetscCall(PetscLayoutReference(V->map,&W->map));
    1600:   PetscCall(BVSetVecType(W,V->vtype));
    1601:   W->ld           = V->ld;
    1602:   PetscCall(BVSetType(W,((PetscObject)V)->type_name));
    1603:   W->orthog_type  = V->orthog_type;
    1604:   W->orthog_ref   = V->orthog_ref;
    1605:   W->orthog_eta   = V->orthog_eta;
    1606:   W->orthog_block = V->orthog_block;
    1607:   if (V->matrix) PetscCall(PetscObjectReference((PetscObject)V->matrix));
    1608:   W->matrix       = V->matrix;
    1609:   W->indef        = V->indef;
    1610:   W->vmm          = V->vmm;
    1611:   W->rrandom      = V->rrandom;
    1612:   W->deftol       = V->deftol;
    1613:   if (V->rand) PetscCall(PetscObjectReference((PetscObject)V->rand));
    1614:   W->rand         = V->rand;
    1615:   W->sfocalled    = V->sfocalled;
    1616:   PetscTryTypeMethod(V,duplicate,W);
    1617:   PetscCall(PetscObjectStateIncrease((PetscObject)W));
    1618:   PetscFunctionReturn(PETSC_SUCCESS);
    1619: }

    1621: /*@
    1622:    BVDuplicate - Creates a new basis vector object of the same type and
    1623:    dimensions as an existing one.

    1625:    Collective

    1627:    Input Parameter:
    1628: .  V - basis vectors context

    1630:    Output Parameter:
    1631: .  W - location to put the new BV

    1633:    Notes:
    1634:    The new BV has the same type and dimensions as V. Also, the inner
    1635:    product matrix and orthogonalization options are copied.

    1637:    BVDuplicate() DOES NOT COPY the entries, but rather allocates storage
    1638:    for the new basis vectors. Use BVCopy() to copy the contents.

    1640:    Level: intermediate

    1642: .seealso: BVDuplicateResize(), BVCreate(), BVSetSizesFromVec(), BVCopy()
    1643: @*/
    1644: PetscErrorCode BVDuplicate(BV V,BV *W)
    1645: {
    1646:   PetscFunctionBegin;
    1649:   BVCheckSizes(V,1);
    1650:   PetscAssertPointer(W,2);
    1651:   PetscCall(BVCreate(PetscObjectComm((PetscObject)V),W));
    1652:   (*W)->N = V->N;
    1653:   (*W)->n = V->n;
    1654:   (*W)->m = V->m;
    1655:   (*W)->k = V->m;
    1656:   PetscCall(BVDuplicate_Private(V,*W));
    1657:   PetscFunctionReturn(PETSC_SUCCESS);
    1658: }

    1660: /*@
    1661:    BVDuplicateResize - Creates a new basis vector object of the same type and
    1662:    dimensions as an existing one, but with possibly different number of columns.

    1664:    Collective

    1666:    Input Parameters:
    1667: +  V - basis vectors context
    1668: -  m - the new number of columns

    1670:    Output Parameter:
    1671: .  W - location to put the new BV

    1673:    Note:
    1674:    This is equivalent of a call to BVDuplicate() followed by BVResize(). The
    1675:    contents of V are not copied to W.

    1677:    Level: intermediate

    1679: .seealso: BVDuplicate(), BVResize()
    1680: @*/
    1681: PetscErrorCode BVDuplicateResize(BV V,PetscInt m,BV *W)
    1682: {
    1683:   PetscFunctionBegin;
    1686:   BVCheckSizes(V,1);
    1688:   PetscAssertPointer(W,3);
    1689:   PetscCall(BVCreate(PetscObjectComm((PetscObject)V),W));
    1690:   (*W)->N = V->N;
    1691:   (*W)->n = V->n;
    1692:   (*W)->m = m;
    1693:   (*W)->k = m;
    1694:   PetscCall(BVDuplicate_Private(V,*W));
    1695:   PetscFunctionReturn(PETSC_SUCCESS);
    1696: }

    1698: /*@
    1699:    BVGetCachedBV - Returns a BV object stored internally that holds the
    1700:    result of B*X after a call to BVApplyMatrixBV().

    1702:    Collective

    1704:    Input Parameter:
    1705: .  bv    - the basis vectors context

    1707:    Output Parameter:
    1708: .  cached - the cached BV

    1710:    Note:
    1711:    The cached BV is created if not available previously.

    1713:    Level: developer

    1715: .seealso: BVApplyMatrixBV()
    1716: @*/
    1717: PetscErrorCode BVGetCachedBV(BV bv,BV *cached)
    1718: {
    1719:   PetscFunctionBegin;
    1721:   PetscAssertPointer(cached,2);
    1722:   BVCheckSizes(bv,1);
    1723:   if (!bv->cached) {
    1724:     PetscCall(BVCreate(PetscObjectComm((PetscObject)bv),&bv->cached));
    1725:     bv->cached->N = bv->N;
    1726:     bv->cached->n = bv->n;
    1727:     bv->cached->m = bv->m;
    1728:     bv->cached->k = bv->m;
    1729:     PetscCall(BVDuplicate_Private(bv,bv->cached));
    1730:   }
    1731:   *cached = bv->cached;
    1732:   PetscFunctionReturn(PETSC_SUCCESS);
    1733: }

    1735: /*@
    1736:    BVCopy - Copies a basis vector object into another one, W <- V.

    1738:    Logically Collective

    1740:    Input Parameter:
    1741: .  V - basis vectors context

    1743:    Output Parameter:
    1744: .  W - the copy

    1746:    Note:
    1747:    Both V and W must be distributed in the same manner; local copies are
    1748:    done. Only active columns (excluding the leading ones) are copied.
    1749:    In the destination W, columns are overwritten starting from the leading ones.
    1750:    Constraints are not copied.

    1752:    Level: beginner

    1754: .seealso: BVCopyVec(), BVCopyColumn(), BVDuplicate(), BVSetActiveColumns()
    1755: @*/
    1756: PetscErrorCode BVCopy(BV V,BV W)
    1757: {
    1758:   PetscScalar       *womega;
    1759:   const PetscScalar *vomega;

    1761:   PetscFunctionBegin;
    1764:   BVCheckSizes(V,1);
    1765:   BVCheckOp(V,1,copy);
    1768:   BVCheckSizes(W,2);
    1769:   PetscCheckSameTypeAndComm(V,1,W,2);
    1770:   PetscCheck(V->n==W->n,PetscObjectComm((PetscObject)V),PETSC_ERR_ARG_INCOMP,"Mismatching local dimension V %" PetscInt_FMT ", W %" PetscInt_FMT,V->n,W->n);
    1771:   PetscCheck(V->k-V->l<=W->m-W->l,PetscObjectComm((PetscObject)V),PETSC_ERR_ARG_SIZ,"W has %" PetscInt_FMT " non-leading columns, not enough to store %" PetscInt_FMT " columns",W->m-W->l,V->k-V->l);
    1772:   if (V==W || !V->n) PetscFunctionReturn(PETSC_SUCCESS);

    1774:   PetscCall(PetscLogEventBegin(BV_Copy,V,W,0,0));
    1775:   if (V->indef && V->matrix && V->indef==W->indef && V->matrix==W->matrix) {
    1776:     /* copy signature */
    1777:     PetscCall(BV_AllocateSignature(W));
    1778:     PetscCall(VecGetArrayRead(V->omega,&vomega));
    1779:     PetscCall(VecGetArray(W->omega,&womega));
    1780:     PetscCall(PetscArraycpy(womega+W->nc+W->l,vomega+V->nc+V->l,V->k-V->l));
    1781:     PetscCall(VecRestoreArray(W->omega,&womega));
    1782:     PetscCall(VecRestoreArrayRead(V->omega,&vomega));
    1783:   }
    1784:   PetscUseTypeMethod(V,copy,W);
    1785:   PetscCall(PetscLogEventEnd(BV_Copy,V,W,0,0));
    1786:   PetscCall(PetscObjectStateIncrease((PetscObject)W));
    1787:   PetscFunctionReturn(PETSC_SUCCESS);
    1788: }

    1790: /*@
    1791:    BVCopyVec - Copies one of the columns of a basis vectors object into a Vec.

    1793:    Logically Collective

    1795:    Input Parameters:
    1796: +  V - basis vectors context
    1797: -  j - the column number to be copied

    1799:    Output Parameter:
    1800: .  w - the copied column

    1802:    Note:
    1803:    Both V and w must be distributed in the same manner; local copies are done.

    1805:    Level: beginner

    1807: .seealso: BVCopy(), BVCopyColumn(), BVInsertVec()
    1808: @*/
    1809: PetscErrorCode BVCopyVec(BV V,PetscInt j,Vec w)
    1810: {
    1811:   PetscInt       n,N;
    1812:   Vec            z;

    1814:   PetscFunctionBegin;
    1817:   BVCheckSizes(V,1);
    1820:   PetscCheckSameComm(V,1,w,3);

    1822:   PetscCall(VecGetSize(w,&N));
    1823:   PetscCall(VecGetLocalSize(w,&n));
    1824:   PetscCheck(N==V->N && n==V->n,PetscObjectComm((PetscObject)V),PETSC_ERR_ARG_INCOMP,"Vec sizes (global %" PetscInt_FMT ", local %" PetscInt_FMT ") do not match BV sizes (global %" PetscInt_FMT ", local %" PetscInt_FMT ")",N,n,V->N,V->n);

    1826:   PetscCall(PetscLogEventBegin(BV_Copy,V,w,0,0));
    1827:   PetscCall(BVGetColumn(V,j,&z));
    1828:   PetscCall(VecCopy(z,w));
    1829:   PetscCall(BVRestoreColumn(V,j,&z));
    1830:   PetscCall(PetscLogEventEnd(BV_Copy,V,w,0,0));
    1831:   PetscFunctionReturn(PETSC_SUCCESS);
    1832: }

    1834: /*@
    1835:    BVCopyColumn - Copies the values from one of the columns to another one.

    1837:    Logically Collective

    1839:    Input Parameters:
    1840: +  V - basis vectors context
    1841: .  j - the number of the source column
    1842: -  i - the number of the destination column

    1844:    Level: beginner

    1846: .seealso: BVCopy(), BVCopyVec()
    1847: @*/
    1848: PetscErrorCode BVCopyColumn(BV V,PetscInt j,PetscInt i)
    1849: {
    1850:   PetscScalar *omega;

    1852:   PetscFunctionBegin;
    1855:   BVCheckSizes(V,1);
    1858:   if (j==i) PetscFunctionReturn(PETSC_SUCCESS);

    1860:   PetscCall(PetscLogEventBegin(BV_Copy,V,0,0,0));
    1861:   if (V->omega) {
    1862:     PetscCall(VecGetArray(V->omega,&omega));
    1863:     omega[i] = omega[j];
    1864:     PetscCall(VecRestoreArray(V->omega,&omega));
    1865:   }
    1866:   PetscUseTypeMethod(V,copycolumn,j,i);
    1867:   PetscCall(PetscLogEventEnd(BV_Copy,V,0,0,0));
    1868:   PetscCall(PetscObjectStateIncrease((PetscObject)V));
    1869:   PetscFunctionReturn(PETSC_SUCCESS);
    1870: }

    1872: static PetscErrorCode BVGetSplit_Private(BV bv,PetscBool left,BV *split)
    1873: {
    1874:   PetscInt  ncols;

    1876:   PetscFunctionBegin;
    1877:   ncols = left? bv->nc+bv->l: bv->m-bv->l;
    1878:   if (*split && ncols!=(*split)->m) PetscCall(BVDestroy(split));
    1879:   if (!*split) {
    1880:     PetscCall(BVCreate(PetscObjectComm((PetscObject)bv),split));
    1881:     (*split)->issplit = left? 1: 2;
    1882:     (*split)->splitparent = bv;
    1883:     (*split)->N = bv->N;
    1884:     (*split)->n = bv->n;
    1885:     (*split)->m = bv->m;
    1886:     (*split)->k = bv->m;
    1887:     PetscCall(BVDuplicate_Private(bv,*split));
    1888:   }
    1889:   (*split)->l  = 0;
    1890:   (*split)->k  = left? bv->l: bv->k-bv->l;
    1891:   (*split)->nc = left? bv->nc: 0;
    1892:   (*split)->m  = ncols-(*split)->nc;
    1893:   if ((*split)->nc) {
    1894:     (*split)->ci[0] = -(*split)->nc-1;
    1895:     (*split)->ci[1] = -(*split)->nc-1;
    1896:   }
    1897:   if (left) PetscCall(PetscObjectStateGet((PetscObject)*split,&bv->lstate));
    1898:   else PetscCall(PetscObjectStateGet((PetscObject)*split,&bv->rstate));
    1899:   PetscFunctionReturn(PETSC_SUCCESS);
    1900: }

    1902: /*@
    1903:    BVGetSplit - Splits the BV object into two BV objects that share the
    1904:    internal data, one of them containing the leading columns and the other
    1905:    one containing the remaining columns.

    1907:    Collective

    1909:    Input Parameter:
    1910: .  bv - the basis vectors context

    1912:    Output Parameters:
    1913: +  L - left BV containing leading columns (can be NULL)
    1914: -  R - right BV containing remaining columns (can be NULL)

    1916:    Notes:
    1917:    The columns are split in two sets. The leading columns (including the
    1918:    constraints) are assigned to the left BV and the remaining columns
    1919:    are assigned to the right BV. The number of leading columns, as
    1920:    specified with BVSetActiveColumns(), must be between 1 and m-1 (to
    1921:    guarantee that both L and R have at least one column).

    1923:    The returned BV's must be seen as references (not copies) of the input
    1924:    BV, that is, modifying them will change the entries of bv as well.
    1925:    The returned BV's must not be destroyed. BVRestoreSplit() must be called
    1926:    when they are no longer needed.

    1928:    Pass NULL for any of the output BV's that is not needed.

    1930:    Level: advanced

    1932: .seealso: BVRestoreSplit(), BVSetActiveColumns(), BVSetNumConstraints()
    1933: @*/
    1934: PetscErrorCode BVGetSplit(BV bv,BV *L,BV *R)
    1935: {
    1936:   PetscFunctionBegin;
    1939:   BVCheckSizes(bv,1);
    1940:   PetscCheck(bv->l,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Must indicate the number of leading columns with BVSetActiveColumns()");
    1941:   PetscCheck(!bv->lsplit,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Cannot get the split BV's twice before restoring them with BVRestoreSplit()");
    1942:   bv->lsplit = bv->nc+bv->l;
    1943:   PetscCall(BVGetSplit_Private(bv,PETSC_TRUE,&bv->L));
    1944:   PetscCall(BVGetSplit_Private(bv,PETSC_FALSE,&bv->R));
    1945:   if (L) *L = bv->L;
    1946:   if (R) *R = bv->R;
    1947:   PetscFunctionReturn(PETSC_SUCCESS);
    1948: }

    1950: /*@
    1951:    BVRestoreSplit - Restore the BV objects obtained with BVGetSplit().

    1953:    Logically Collective

    1955:    Input Parameters:
    1956: +  bv - the basis vectors context
    1957: .  L  - left BV obtained with BVGetSplit()
    1958: -  R  - right BV obtained with BVGetSplit()

    1960:    Note:
    1961:    The arguments must match the corresponding call to BVGetSplit().

    1963:    Level: advanced

    1965: .seealso: BVGetSplit()
    1966: @*/
    1967: PetscErrorCode BVRestoreSplit(BV bv,BV *L,BV *R)
    1968: {
    1969:   PetscFunctionBegin;
    1972:   BVCheckSizes(bv,1);
    1973:   PetscCheck(bv->lsplit,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Must call BVGetSplit first");
    1974:   PetscCheck(!L || *L==bv->L,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Argument 2 is not the same BV that was obtained with BVGetSplit");
    1975:   PetscCheck(!R || *R==bv->R,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONG,"Argument 3 is not the same BV that was obtained with BVGetSplit");
    1976:   PetscCheck(!L || ((*L)->ci[0]<=(*L)->nc-1 && (*L)->ci[1]<=(*L)->nc-1),PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Argument 2 has unrestored columns, use BVRestoreColumn()");
    1977:   PetscCheck(!R || ((*R)->ci[0]<=(*R)->nc-1 && (*R)->ci[1]<=(*R)->nc-1),PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_WRONGSTATE,"Argument 3 has unrestored columns, use BVRestoreColumn()");

    1979:   PetscTryTypeMethod(bv,restoresplit,L,R);
    1980:   bv->lsplit = 0;
    1981:   if (L) *L = NULL;
    1982:   if (R) *R = NULL;
    1983:   PetscFunctionReturn(PETSC_SUCCESS);
    1984: }

    1986: /*@
    1987:    BVSetDefiniteTolerance - Set the tolerance to be used when checking a
    1988:    definite inner product.

    1990:    Logically Collective

    1992:    Input Parameters:
    1993: +  bv     - basis vectors
    1994: -  deftol - the tolerance

    1996:    Options Database Key:
    1997: .  -bv_definite_tol <deftol> - the tolerance

    1999:    Notes:
    2000:    When using a non-standard inner product, see BVSetMatrix(), the solver needs
    2001:    to compute sqrt(z'*B*z) for various vectors z. If the inner product has not
    2002:    been declared indefinite, the value z'*B*z must be positive, but due to
    2003:    rounding error a tiny value may become negative. A tolerance is used to
    2004:    detect this situation. Likewise, in complex arithmetic z'*B*z should be
    2005:    real, and we use the same tolerance to check whether a nonzero imaginary part
    2006:    can be considered negligible.

    2008:    This function sets this tolerance, which defaults to 10*eps, where eps is
    2009:    the machine epsilon. The default value should be good for most applications.

    2011:    Level: advanced

    2013: .seealso: BVSetMatrix()
    2014: @*/
    2015: PetscErrorCode BVSetDefiniteTolerance(BV bv,PetscReal deftol)
    2016: {
    2017:   PetscFunctionBegin;
    2020:   if (deftol == (PetscReal)PETSC_DEFAULT) bv->deftol = 10*PETSC_MACHINE_EPSILON;
    2021:   else {
    2022:     PetscCheck(deftol>0.0,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of deftol. Must be > 0");
    2023:     bv->deftol = deftol;
    2024:   }
    2025:   PetscFunctionReturn(PETSC_SUCCESS);
    2026: }

    2028: /*@
    2029:    BVGetDefiniteTolerance - Returns the tolerance for checking a definite
    2030:    inner product.

    2032:    Not Collective

    2034:    Input Parameter:
    2035: .  bv - the basis vectors

    2037:    Output Parameter:
    2038: .  deftol - the tolerance

    2040:    Level: advanced

    2042: .seealso: BVSetDefiniteTolerance()
    2043: @*/
    2044: PetscErrorCode BVGetDefiniteTolerance(BV bv,PetscReal *deftol)
    2045: {
    2046:   PetscFunctionBegin;
    2048:   PetscAssertPointer(deftol,2);
    2049:   *deftol = bv->deftol;
    2050:   PetscFunctionReturn(PETSC_SUCCESS);
    2051: }

    2053: /*@
    2054:    BVSetLeadingDimension - Set the leading dimension to be used for storing the BV data.

    2056:    Not Collective

    2058:    Input Parameters:
    2059: +  bv - basis vectors
    2060: -  ld - the leading dimension

    2062:    Notes:
    2063:    This parameter is relevant for BVMAT, though it might be employed in other types
    2064:    as well.

    2066:    When the internal data of the BV is stored as a dense matrix, the leading dimension
    2067:    has the same meaning as in MatDenseSetLDA(), i.e., the distance in number of
    2068:    elements from one entry of the matrix to the one in the next column at the same
    2069:    row. The leading dimension refers to the local array, and hence can be different
    2070:    in different processes.

    2072:    The user does not need to change this parameter. The default value is equal to the
    2073:    number of local rows, but this value may be increased a little to guarantee alignment
    2074:    (especially in the case of GPU storage).

    2076:    Level: advanced

    2078: .seealso: BVGetLeadingDimension()
    2079: @*/
    2080: PetscErrorCode BVSetLeadingDimension(BV bv,PetscInt ld)
    2081: {
    2082:   PetscFunctionBegin;
    2085:   PetscCheck((bv->n<0 && bv->N<0) || !bv->ops->create,PetscObjectComm((PetscObject)bv),PETSC_ERR_ORDER,"Must call BVSetLeadingDimension() before setting the BV type and sizes");
    2086:   if (ld == PETSC_DEFAULT) bv->ld = 0;
    2087:   else {
    2088:     PetscCheck(ld>0,PetscObjectComm((PetscObject)bv),PETSC_ERR_ARG_OUTOFRANGE,"Illegal value of ld. Must be > 0");
    2089:     bv->ld = ld;
    2090:   }
    2091:   PetscFunctionReturn(PETSC_SUCCESS);
    2092: }

    2094: /*@
    2095:    BVGetLeadingDimension - Returns the leading dimension of the BV.

    2097:    Not Collective

    2099:    Input Parameter:
    2100: .  bv - the basis vectors

    2102:    Output Parameter:
    2103: .  ld - the leading dimension

    2105:    Level: advanced

    2107:    Notes:
    2108:    The returned value may be different in different processes.

    2110:    The leading dimension must be used when accessing the internal array via
    2111:    BVGetArray() or BVGetArrayRead().

    2113: .seealso: BVSetLeadingDimension(), BVGetArray(), BVGetArrayRead()
    2114: @*/
    2115: PetscErrorCode BVGetLeadingDimension(BV bv,PetscInt *ld)
    2116: {
    2117:   PetscFunctionBegin;
    2119:   PetscAssertPointer(ld,2);
    2120:   *ld = bv->ld;
    2121:   PetscFunctionReturn(PETSC_SUCCESS);
    2122: }