slepc-3.21.1 2024-04-26
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Computes multiple dot products of a column against all the previous columns of a BV.


#include "slepcbv.h" 
PetscErrorCode BVDotColumn(BV X,PetscInt j,PetscScalar *q)

Input Parameters

X  - basis vectors
j  - the column index

Output Parameter

q  - an array where the result must be placed


This operation is equivalent to BVDotVec() but it uses column j of X rather than taking a Vec as an argument. The number of active columns of X is set to j before the computation, and restored afterwards. If X has leading columns specified, then these columns do not participate in the computation. Therefore, the length of array q must be equal to j minus the number of leading columns.

Developer Notes

If q is NULL, then the result is written in position nc+l of the internal buffer vector, see BVGetBufferVec().

See Also

BVDot(), BVDotVec(), BVSetActiveColumns(), BVSetMatrix()





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