petsc-3.8.4 2018-03-24

DMCoarsenHookAdd

adds a callback to be run when restricting a nonlinear problem to the coarse grid

Synopsis

#include "petscdm.h"          
#include "petscdmlabel.h"     
#include "petscds.h"     
PetscErrorCode DMCoarsenHookAdd(DM fine,PetscErrorCode (*coarsenhook)(DM,DM,void*),PetscErrorCode (*restricthook)(DM,Mat,Vec,Mat,DM,void*),void *ctx)

Logically Collective

Input Arguments

	fine	- nonlinear solver context on which to run a hook when restricting to a coarser level
	coarsenhook	- function to run when setting up a coarser level
	restricthook	- function to run to update data on coarser levels (once per SNESSolve())
	ctx	- [optional] user-defined context for provide data for the hooks (may be NULL)

Calling sequence of coarsenhook

   coarsenhook(DM fine,DM coarse,void *ctx);

	fine	- fine level DM
	coarse	- coarse level DM to restrict problem to
	ctx	- optional user-defined function context

Calling sequence for restricthook

   restricthook(DM fine,Mat mrestrict,Vec rscale,Mat inject,DM coarse,void *ctx)

	fine	- fine level DM
	mrestrict	- matrix restricting a fine-level solution to the coarse grid
	rscale	- scaling vector for restriction
	inject	- matrix restricting by injection
	coarse	- coarse level DM to update
	ctx	- optional user-defined function context

Notes

This function is only needed if auxiliary data needs to be set up on coarse grids.

If this function is called multiple times, the hooks will be run in the order they are added.

In order to compose with nonlinear preconditioning without duplicating storage, the hook should be implemented to extract the finest level information from its context (instead of from the SNES).

This function is currently not available from Fortran.

Examples

src/snes/examples/tutorials/ex48.c.html