BVMultInPlace#

Update a set of vectors as \(V_{:,s:e-1} = V Q_{:,s:e-1}\).

Synopsis#

#include "slepcbv.h" 
PetscErrorCode BVMultInPlace(BV V,Mat Q,PetscInt s,PetscInt e)

Logically Collective

Input Parameters#

Q - a sequential dense matrix
s - first column of V to be overwritten
e - first column of V not to be overwritten

Input/Output Parameter#

V - basis vectors

Notes#

The matrix Q must be a sequential dense Mat, with all entries equal on all processes (otherwise each process will compute a different update).

This function computes \(V_{:,s:e-1} = V Q_{:,s:e-1}\), that is, given a set of vectors \(V\), columns from \(s\) to \(e-1\) are overwritten with columns from \(s\) to \(e-1\) of the matrix-matrix product \(V Q\). Only columns \(s\) to \(e-1\) of Q are referenced.