slepc-3.18.1 2022-11-02
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# BVMultVec

Computes y = beta*y + alpha*X*q.

### Synopsis

    #include "slepcbv.h"
    PetscErrorCode BVMultVec(BV X,PetscScalar alpha,PetscScalar beta,Vec y,PetscScalar q[])

Logically Collective on X

### Input Parameters

| X | - a basis vectors object
| alpha | - first scalar
| beta | - second scalar
| y | - a vector (modified on output)
| q | - an array of scalars

### Notes

This operation is the analogue of BVMult() but with a BV and a Vec, instead of two BV. Note that arguments are listed in different order with respect to BVMult().

If X has leading columns specified, then these columns do not participate in the computation.

The length of array q must be equal to the number of active columns of X minus the number of leading columns, i.e. the first entry of q multiplies the first non-leading column.

### See Also

BVMult(), BVMultColumn(), BVMultInPlace(), BVSetActiveColumns()

### Level

intermediate

### Location

src/sys/classes/bv/interface/bvops.c
Index of all BV routines
Table of Contents for all manual pages
Index of all manual pages