slepc-main 2024-12-17
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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

buffer  - vector

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