petsc-3.8.4 2018-03-24

SNESSetNGS

Sets the user nonlinear Gauss-Seidel routine for use with composed nonlinear solvers.

#include "petscsnes.h"  
PetscErrorCode SNESSetNGS(SNES snes,PetscErrorCode (*f)(SNES,Vec,Vec,void*),void *ctx)

	snes	- the SNES context
	f	- function evaluation routine to apply Gauss-Seidel see SNESNGSFunction
	ctx	- [optional] user-defined context for private data for the smoother evaluation routine (may be NULL)

The NGS routines are used by the composed nonlinear solver to generate a problem appropriate update to the solution, particularly FAS.

SNES, nonlinear, set, Gauss-Seidel