ffc team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

Garth N. Wells wrote:
> Kent Andre wrote:
> > > Not sure what we have to do actually. I suppose I want get any clue 
> > > from the
> > >   demo/function/restriction
> > >
> > > demo?
> > > I see that Kent has modified the dolfin.FunctionSpace to reflect the 
> > > present (broken) implementation of restriction, anything in that 
> > > line? Should such an implementation has been done in 
> > > FunctionSpaceBase instead of FunctionSpace? Kent?
> > >
> > > Johan
> >
> > This restriction is different in the sense that the restriction is made
> > by the standard element on a sub mesh.
> > The restriction in focus now is on the complete mesh but for only
> > a part of the element.
> > Combined, these two features will be very powerful.  I guess the 
> > sub-mesh restriction stuff is broken due to the parallel mesh.
>
>
> I've attached an example solver. To make it work for P^k with k > 2 we 
> need to restrict some functions to cell facets. Using FFC, we do
>
>     scalar  = FiniteElement("Lagrange", "triangle", 3)
>     dscalar = FiniteElement("Discontinuous Lagrange", "triangle", 3)
>
>     # This syntax restricts the space 'scalar' to cell facets.
>     mixed = scalar["facet"] + dscalar
>
> In PyDOLFIN we could do
>
>     V_dg = FunctionSpace(mesh, "DG", 3)
>     V_cg = FunctionSpace(mesh, "CG", 3, "facet")
>
>     mixed = V_cg + V_dg

I see now that we need to have the above option since the everything 
(e.g. the dof map) is created and compiled inside functionspace.py.

Garth

> or
>
>     V_dg = FunctionSpace(mesh, "DG", 3)
>     V_cg = FunctionSpace(mesh, "CG", 3)
>
>     mixed = V_cg["scalar"] + V_dg
>
> Garth
>
> > Kent
> >
> > _______________________________________________
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> > DOLFIN-dev@xxxxxxxxxx
> > http://www.fenics.org/mailman/listinfo/dolfin-dev
>
>
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