dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

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)?

/Anders