SNESGetJacobian

Returns the Jacobian matrix and optionally the user provided context for evaluating the Jacobian.

#include "petscsnes.h"  
int SNESGetJacobian(SNES snes,Mat *A,Mat *B,void **ctx,int (**func)(SNES,Vec,Mat*,Mat*,MatStructure*,void*))

Not Collective, but Mat object will be parallel if SNES object is

snes -the nonlinear solver context

	A	- location to stash Jacobian matrix (or PETSC_NULL)
	B	- location to stash preconditioner matrix (or PETSC_NULL)
	ctx	- location to stash Jacobian ctx (or PETSC_NULL)
	func	- location to put Jacobian function (or PETSC_NULL)