dolfin team mailing list archive

["Garth N. Wells" <g.n.wells@xxxxxxxxxx>]

Anders Logg wrote:
> On Tue, Oct 17, 2006 at 06:30:09PM +0200, Anders Logg wrote:
>> On Tue, Oct 17, 2006 at 03:09:50PM +0200, Garth N. Wells wrote:
>>
>>>> and you have it. For any cell in that mesh, you may then do
>>>>
>>>>     uint* edges = cell.connections(1);
>>>>
>>>> Which gives you the global edge numbers for the three edges of the
>>>> cell. The local numbers are 0, 1, 2.
>>>>
>>>> Is that what you mean?
>>>>
>>> What I would like is the other way around. For a given facet, I need to
>>> it's local ID (0, 1 or 2) relative to the cells which is it connected
>>> to. Basically, on the boundary, I now have the facet and the mesh cell,
>>> but I don't know the local facet number (FFC generate output for each case).
>>>
>>> I could use the above way and iterate over each mesh cell which has a
>>> boundary facet, and work out which facet is on the boundary.
>> ok, now I remember. I forgot we had this before by localID().
>>
>> Is this needed only for the boundary? If so, we could add it as
>> another MeshFunction that gets computed when the boundary is
>> generated. In that case, we compute this in BoundaryComputation.
>>
>> Or do we need something more general, so for any given pair of
>> entities (e0, e1), e0 can ask e1: Who am I to you?
>>
>> /Anders
> 
> Looks like we need the more general information when we start doing
> discontinuous Galerkin (which is soon)?
>

Yes, we will need the general case. For now, I'm computing the local
index in FEM.cpp.

Garth

> /Anders
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