[petsc-users] DMPlex in Fortran

[Matthew Knepley]

On Fri, Jul 8, 2022 at 11:26 PM Mike Michell <mi.mike1021 at gmail.com> wrote:

> I am using DMPlex for a code with written in Fortran in 2D and 3D. There
> were two questions.
>
> - As a follow up of the previous inquiry:
> https://www.mail-archive.com/petsc-users@mcs.anl.gov/msg43856.html
> Is the local-to-local halo exchange available in Fortran now or still
> pending? Currently local-to-global and global-to-local communication are
> used since local-to-local has not been allowed for Fortran.
>

Sorry, it is still on my TODO list. I am trying to get stuff cleared out.


> - One code solves discretized equations at each vertex, and another code I
> want to couple physics is solving equations at each cell centroid.
> Basically, the value at cell centroid needs to be mapped to vertex (or vice
> versa) through interpolation/extrapolation for coupling of two codes. Does
> petsc function provide this kind of mapping between cell centroid and
> vertex? The grids for the two codes can be overlapped. I was trying to find
> some FEM infrastructures in petsc, but so far havent found that kind of
> functionality. Can I get any comments on that?
>

Yes, you can create both P0 and P1 discretizations (PetscFECreateLagrange)
in two different DMs using DMClone(), and then create an interpolation
operator (DMPlexCreateInterpolator) which maps between them. Let me know if
something is not clear there.

  Thanks,

    Matt


> Thanks,
> Mike
>
>

-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener

https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20220709/b52ddbfb/attachment.html>