[petsc-users] DMPlexCreateFromCellList and hybrid meshes

[Jed Brown]

Cedric Doucet <cedric.doucet at inria.fr> writes:

> I could use DMPlexCreateFromDAG but there are several drawbacks:
> 1. DMPlexCreateFromDAG is not well documented;
> 2. other developers will have to understand a tricky data structure
> (DAG) to modify my code (see point 1 to understand why it is a
> problem);;

Every public function is supposed to have a man page.  Matt neglected
this rule in DMPlexCreateFromDAG and it's perfectly valid to complain
about that.  However, I think DMPlexCreateFromDAG provides the
functionality you need, and is sufficiently general to deal with things
like boundary faces which are needed for most real simulations.

> 3. DMPlexCreateFromDAG looks like a low-level function in comparison
> with DMPlexCreateFromCellList which acts at a higher level: if you
> modify this structure, I or someone else will have to modify my code
> (see point 2 to understand why it is a problem);

It only uses complicated words; the data structure is basically the same
as what you're asking for, with the added flexibility of being able to
represent meshes containing cells with more than one topological
dimension (e.g., volumes and faces).

> You proposed to modify DMPlexCreateFromCellList function for me and I
> decided to accept it after thinking about it.  Did you change your
> mind?

I didn't propose that.  Maybe Matt did and of course he's welcome to
generalize the function.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 835 bytes
Desc: not available
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20140103/10be94fb/attachment.pgp>