BVSetActiveColumns#

Specify the columns that will be involved in operations.

Synopsis#

#include "slepcbv.h" 
PetscErrorCode BVSetActiveColumns(BV bv,PetscInt l,PetscInt k)

Logically Collective

Input Parameters#

  • bv - the basis vectors context

  • l - number of leading columns

  • k - number of active columns

Notes#

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

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

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

Use PETSC_CURRENT to leave any of the values unchanged. Use PETSC_DETERMINE to set l to the minimum value (0) and k to the maximum (m).

See Also#

BVGetActiveColumns(), BVSetSizes()

Level#

intermediate

Location#

src/sys/classes/bv/interface/bvbasic.c

Index of all BV routines Table of Contents for all manual pages Index of all manual pages