[petsc-users] Element to local dof map using dmplex

[Matthew Knepley]

On Tue, Oct 25, 2016 at 6:39 AM, Morten Nobel-Jørgensen <mono at dtu.dk> wrote:

> Dear Matt
>
> Did you (or anyone else) find time to look at our issue?
>
> We are really looking forward to your answer :)
>

Yes, I had a little difficulty understanding what was going on, but now I
think I see. I am
attaching my modified ex19.cc. Please look at the sections marked with
'MGK'. The largest
change is that I think you can dispense with your matrix data structure,
and just call
DMPlexVecGetValuesClosure (for coordinates) and DMPlexMatSetValuesClosure
(for element matrices).
I did not understand what you needed to modify for ExodusII.

  Thanks,

    Matt


> Kind regards,
> Morten
> ------------------------------
> *From:* Matthew Knepley [knepley at gmail.com]
> *Sent:* Wednesday, October 12, 2016 3:41 PM
> *To:* Morten Nobel-Jørgensen
> *Cc:* petsc-users at mcs.anl.gov
> *Subject:* Re: Element to local dof map using dmplex
>
> On Wed, Oct 12, 2016 at 6:40 AM, Morten Nobel-Jørgensen <mono at dtu.dk>
> wrote:
>
>> Dear PETSc developers / Matt
>>
>> Thanks for your suggestions regarding our use of dmplex in a FEM context.
>> However, Matt's advise on  using the PetscFE is not sufficient for our
>> needs (our end goal is a topology optimization framework - not just FEM)
>> and we must honestly admit that we do not see how we can use the MATIS and
>> the MatSetValuesClosure or DMPlexMatSetClosure to solve our current issues
>> as Stefano has suggested.
>>
>> We have therefore created a more representative, yet heavily
>> oversimplified, code example that demonstrates our problem. That is, the
>> dof handling is only correct on a single process and goes wrong on np>1.
>>
>> We hope very much that you can help us to overcome our problem.
>>
>
> Okay, I will look at it and try to rework it to fix your problem.
>
> I am in London this week, so it might take me until next week.
>
>   Thanks,
>
>      Matt
>
>
>> Thank you for an excellent toolkit
>> Morten and Niels
>>
>
>
>
> --
> 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
>



-- 
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
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