PETSc version 3.15.5
SNESSetUpdate
Sets the general-purpose update function called at the beginning of every iteration of the nonlinear solve. Specifically it is called just before the Jacobian is "evaluated". 
Synopsis
#include "petscsnes.h"  
PetscErrorCode  SNESSetUpdate(SNES snes, PetscErrorCode (*func)(SNES, PetscInt))
Logically Collective on SNES
Input Parameters
|  | snes | - The nonlinear solver context | 
|  | func | - The function | 
Calling sequence of func
func (SNES snes, PetscInt step);
|  | step | - The current step of the iteration | 
Note: This is NOT what one uses to update the ghost points before a function evaluation, that should be done at the beginning of your FormFunction()
This is not used by most users.
See Also
SNESSetJacobian(), SNESSolve()
Level
advanced
Location
src/snes/interface/snes.c
Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages