petsc-3.12.5 2020-03-29

SNESGetJacobian

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

#include "petscsnes.h"  
PetscErrorCode SNESGetJacobian(SNES snes,Mat *Amat,Mat *Pmat,PetscErrorCode (**J)(SNES,Vec,Mat,Mat,void*),void **ctx)

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

snes -the nonlinear solver context

	Amat	- location to stash (approximate) Jacobian matrix (or NULL)
	Pmat	- location to stash matrix used to compute the preconditioner (or NULL)
	J	- location to put Jacobian function (or NULL), see SNESJacobianFunction for details on its calling sequence
	ctx	- location to stash Jacobian ctx (or NULL)

advanced