BVGetColumn#
Returns a Vec object that contains the entries of the requested column of the basis vectors object.
Synopsis#
#include "slepcbv.h"
PetscErrorCode BVGetColumn(BV bv,PetscInt j,Vec *v)
Logically Collective
Input Parameters#
bv - the basis vectors context
j - the index of the requested column
Output Parameter#
v - vector containing the jth column
Notes#
The returned Vec must be seen as a reference (not a copy) of the BV column, that is, modifying the Vec will change the BV entries as well.
The returned Vec must not be destroyed. BVRestoreColumn() must be called when it is no longer needed. At most, two columns can be fetched, that is, this function can only be called twice before the corresponding BVRestoreColumn() is invoked.
A negative index j selects the i-th constraint, where i=-j. Constraints should not be modified.
See Also#
BVRestoreColumn(), BVInsertConstraints()
Level#
beginner
Location#
Implementations#
BVGetColumn_Contiguous() in src/sys/classes/bv/impls/contiguous/contig.c
BVGetColumn_Mat() in src/sys/classes/bv/impls/mat/bvmat.c
BVGetColumn_Svec() in src/sys/classes/bv/impls/svec/svec.c
BVGetColumn_Vecs() in src/sys/classes/bv/impls/vecs/vecs.c
Index of all BV routines Table of Contents for all manual pages Index of all manual pages