[petsc-dev] DMPlexAddBoundary

[Adrian Croucher]

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 
> <mailto:jed at jedbrown.org>> wrote:
>
>     Adrian Croucher <a.croucher at auckland.ac.nz
>     <mailto: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...

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

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