petsc-3.3-p7 2013-05-11

MatSubMatrixUpdate

Updates a submatrix

#include "petscmat.h" 
PetscErrorCode  MatSubMatrixUpdate(Mat N,Mat A,IS isrow,IS iscol)

Collective on Mat

	N	- submatrix to update
	A	- full matrix in the submatrix
	isrow	- rows in the update (same as the first time the submatrix was created)
	iscol	- columns in the update (same as the first time the submatrix was created)

Most will use MatGetSubMatrix which provides a more efficient representation if it is available.