[petsc-users] Auxiliary fields for multigrid

[Jed Brown]

"zakaryah ." <zakaryah at gmail.com> writes:

> Ok, thanks for the suggestions.
> ​I'd like to check that I understand the approach.
>
> I create one DMDA for the variables to be solved by the SNES.  That DMDA
> will be coarsened and refined by the options I pass to e.g. FAS.  In my
> user context struct, I can have a second DMDA for the auxiliary fields.  At
> each coarsening or refinement of the solution variable DMDA, I add a hook
> to simultaneously coarsen or refine the auxiliary fields.  I suppose I can
> store the results of those operations in a third DMDA in the user context
> struct, because I'll need to access them from the SNES Function and
> Jacobian routines.  Does that sound right?​

Basically, please look at the example.