SNESDefaultComputeJacobianColor

Computes the Jacobian using finite differences and coloring to exploit matrix sparsity.

#include "petscmat.h"  
#include "petscsnes.h"  
int SNESDefaultComputeJacobianColor(SNES snes,Vec x1,Mat *J,Mat *B,MatStructure *flag,void *ctx)

Collective on SNES

	snes	- nonlinear solver object
	x1	- location at which to evaluate Jacobian
	ctx	- coloring context, where ctx must have type MatFDColoring, as created via MatFDColoringCreate()

	J	- Jacobian matrix (not altered in this routine)
	B	- newly computed Jacobian matrix to use with preconditioner (generally the same as J)
	flag	- flag indicating whether the matrix sparsity structure has changed

-mat_fd_coloring_freq <freq> -Activates SNESDefaultComputeJacobianColor()

SNES, finite differences, Jacobian, coloring, sparse