[petsc-dev] PetscSection

[Matthew Knepley]

On Sat, Nov 10, 2012 at 2:33 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
> On Sat, Nov 10, 2012 at 1:26 PM, Matthew Knepley <knepley at gmail.com> wrote:
>>
>> I do not understand. Codim 0 and 1 are handled in an identical way.
>
>
> The user doesn't do the same thing with them. Your data structure treats
> them the same way (though I'm not sure how you distinguish between a tet and
> a quad if both are "height 0" and you don't store intermediate levels), but
> that seems like an implementation detail to me.

Yes, I agree that they are different geometrically, and in PyLith we
make Labels to
distinguish, which I think is the right way.

>>
>> I am not against some convenience interface for dim/co-dim, however it
>> would
>> just be implemented by making a label, since we have many equivalent
>> structural
>> things which would map to it.
>
>
> 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.

  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