petsc-3.7.5 2017-01-01

VecStrideScale

Scales a subvector of a vector defined by a starting point and a stride.

#include "petscvec.h" 
PetscErrorCode  VecStrideScale(Vec v,PetscInt start,PetscScalar scale)

Logically Collective on Vec

	v	- the vector
	start	- starting point of the subvector (defined by a stride)
	scale	- value to multiply each subvector entry by

One must call VecSetBlockSize() before this routine to set the stride information, or use a vector created from a multicomponent DMDA.

This will only work if the desire subvector is a stride subvector