[petsc-users] DMPlex problem

[Matthew Knepley]

On Fri, Sep 9, 2016 at 9:49 AM, Mark Lohry <mlohry at princeton.edu> wrote:

> Regarding DMPlex, I'm unclear on the separation between Index Sets and
> Plex for unstructured solvers. I've got an existing unstructured serial
> solver using petsc's newton-krylov
>
 Index Sets are lists of integers. They can mean whatever you want, but
they are just lists.

Plex stores mesh topology and has topological query functions.

> solvers. Should I be looking to parallelize this via IS or plex? Is there
> an interface for either that allows me to specify the partitioning (e.g. by
> metis' output)? Last but not least, is
>
There is DMPlexDistribute() which partitions and distributes, or you can
use DMPlexMigrates() if you want to calculate
your own partition for some reason.

> there a working example of dmplex in the docs? The only unstructured code
> example I see in the docs is SNES ex10, which uses IS.
>
SNES ex12, ex62, ex77 and TS ex11.

  Thanks,

    Matt

> Thanks,
>
> Mark
>
> On 09/09/2016 04:21 AM, Matthew Knepley wrote:
>
> On Fri, Sep 9, 2016 at 4:04 AM, Morten Nobel-Jørgensen <mono at dtu.dk>
> wrote:
>
>> Dear PETSc developers and users,
>>
>> Last week we posted a question regarding an error with DMPlex and
>> multiple dofs and have not gotten any feedback yet. This is uncharted
>> waters for us, since we have gotten used to an extremely fast feedback from
>> the PETSc crew. So - with the chance of sounding impatient and ungrateful -
>> we would like to hear if anybody has any ideas that could point us in the
>> right direction?
>>
>
> This is my fault. You have not gotten a response because everyone else was
> waiting for me, and I have been
> slow because I just moved houses at the same time as term started here.
> Sorry about that.
>
> The example ran for me and I saw your problem. The local-tp-global map is
> missing for some reason.
> I am tracking it down now. It should be made by DMCreateMatrix(), so this
> is mysterious. I hope to have
> this fixed by early next week.
>
>   Thanks,
>
>     Matt
>
>
>> We have created a small example problem that demonstrates the error in
>> the matrix assembly.
>>
>> Thanks,
>> Morten
>>
>>
>>
>
>
> --
> 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20160909/a5571081/attachment.html>