[petsc-dev] DMPlexAddBoundary

[Matthew Knepley]

On Wed, May 21, 2014 at 10:21 PM, Adrian Croucher <a.croucher at auckland.ac.nz
> wrote:

>  hi
>
> On 21/05/14 22:43, Matthew Knepley wrote:
>
>  On Wed, May 21, 2014 at 12:46 AM, Jed Brown <jed at jedbrown.org> wrote:
>
>> Adrian Croucher <a.croucher at auckland.ac.nz> writes:
>> > In the 'PhysicsCreate' functions there are calls to DMPlexAddBoundary(),
>> > which takes an array of IDs; e.g. in PhysicsCreate_SW() the IDs are
>> > {100,101,200,300}. It looks like these IDs define where the BCs are
>> > applied, but what do these numbers actually refer to?
>>
>>  They are numbered "face sets" on the Cubit-generated example mesh.
>>
>
> 1) Cubit has a notion of Face Set, which are groups of faces in the mesh
>
>  2) These sets are written out as Face Sets in the ExodusII format
>
>  3) PETSc reads in the ExodusII format and creates a label names Face
> Sets,
>      where the value is the set label (like 101) and the points are the
> set members.
>
>
> Right, thanks very much for explaining that. I had been looking in the
> code to see where those Face Sets label values were being set up- hadn't
> realised they were in the mesh file...
>

You can see me setting up similar labels in DMPlexCreateSquareMesh() for
example.

   Matt


> Cheers, Adrian
>
> --
> Dr Adrian Croucher
> Senior Research Fellow
> Department of Engineering Science
> University of Auckland, New Zealand
> email: a.croucher at auckland.ac.nz
> tel: +64 (0)9 923 4611
>
>


-- 
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-dev/attachments/20140521/337a900b/attachment.html>