[petsc-dev] PetscSection

[Matthew Knepley]

On Sat, Nov 10, 2012 at 2:54 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
> On Sat, Nov 10, 2012 at 1:44 PM, Matthew Knepley <knepley at gmail.com> wrote:
>>
>> Yes, I agree that they are different geometrically, and in PyLith we
>> make Labels to
>> distinguish, which I think is the right way.
>
>
> Cool. Of course you have to create the labels somehow. Do you currently make
> labels for all the "sidesets" in the mesh you load (e.g., from exodus)?

Yep.

> Labels in their current form seem to do two things (denote sets and
> associate values with points in those sets). Don't you frequently want one
> or the other?

Well, you have to designate the set with something. The easiest thing to use is
an integer, so I use that. This is the only value associated with the set, so I
would say Labels really only make sets.

>>
>> > Fine, I care much more about conceptual simplicity in the interface. I
>> > think
>> > adoption will be higher if 95% of users don't see the word "stratum".
>>
>> Note that this will have to be set explicitly somehow, since you cannot
>> "tell"
>> from the DAG that something has a given dimension/co-dim.
>
>
> Are your points not sorted by dimension? (Most of the code I've seen in the
> examples assumes homogeneous strata.)

Exactly, they are sorted by strata, not dimension.

   Matt

--
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