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; No Fortran Support

Input Parameters#

fine - DM 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 (called once per SNESSolve())
ctx - [optional] user-defined context for provide data for the hooks (may be NULL)

Calling sequence of `coarsenhook`#

PetscErrorCode  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 of `restricthook`#

PetscErrorCode  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, usually the transpose of the interpolation
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, attached to the DM with PetscObjectCompose(), needs to be set up or passed from the fine DM to the coarse DM.

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).

The hooks are automatically called by DMRestrict()