slepc-3.23.1 2025-05-01
   
BVGetBufferVec
Obtain the buffer vector associated with the BV object. 
Synopsis
#include "slepcbv.h" 
PetscErrorCode BVGetBufferVec(BV bv,Vec *buffer)
Collective
Input Parameters
|  | bv | - the basis vectors context | 
Output Parameter
Notes
The vector is created if not available previously. It is a sequential vector
of length (nc+m)*m, where m is the number of columns of bv and nc is the number
of constraints.
Developer Notes
The buffer vector is viewed as a column-major matrix with leading dimension
ld=nc+m, and m columns at most. In the most common usage, it has the structure
      | | C |
      |s|---|
      | | H |
where H is an upper Hessenberg matrix of order m x (m-1), C contains coefficients
related to orthogonalization against constraints (first nc rows), and s is the
first column that contains scratch values computed during Gram-Schmidt
orthogonalization. In particular, BVDotColumn() and BVMultColumn() use s to
store the coefficients.
See Also
 BVSetBufferVec(), BVSetSizes(), BVGetNumConstraints(), BVDotColumn(), BVMultColumn()
Level
developer
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