dolfin team mailing list archive

[Johan Hake <hake@xxxxxxxxx>]

On Wednesday 19 August 2009 00:09:21 Garth N. Wells wrote:
> Anders Logg wrote:
> > On Tue, Aug 18, 2009 at 10:36:54PM +0200, Kristian Oelgaard wrote:
> >> Quoting Anders Logg <logg@xxxxxxxxx>:
> >>> On Tue, Aug 18, 2009 at 08:13:22PM +0100, Garth N. Wells wrote:
> >>>>>>>>>>> changeset:   1612:de211a9d88bce134c4abc2b128283ad35415a529
> >>>>>>>>>>> tag:         tip
> >>>>>>>>>>> user:        "Kristian Oelgaard <k.b.oelgaard@xxxxxxxxxx>"
> >>>>>>>>>>> date:        Tue Aug 18 17:57:36 2009 +0100
> >>>>>>>>>>> files:       ffc/fem/finiteelement.py
> >>>>>>>>>>> description:
> >>>>>>>>>>> Restrictions appears to be working for the Poisson demo.
> >>>
> >>> Excellent!
> >>>
> >>>>> No, only interval, triangle, tetrahedron, quadrilateral and
> >>>>> hexahedron
> >>>>>
> >>>>> is predefined in UFL. I assume simplices and restrictions currently
> >>>>> only supports a restriction to one topological dimension lower i.e.,
> >>>>> tetrahedron -> triangle
> >>>>> triangle -> interval
> >>>>
> >>>> We need a 'facet', which is a triangle in 3D and interval in 2D, so we
> >>>> write dimension-independent forms (at least for 2D and 3D).
> >>>
> >>> That should be fairly easy to add to UFL (__getitem__ in
> >>> finiteelement.py). You can check if the input argument is facet (which
> >>> needs to be added), then look at self._cell and figure out the
> >>> appropriate value of index.
> >>>
> >>> Let me know if you have any trouble.
> >>
> >> OK, this functionality should be in place now. Do note that the built-in
> >> facet has no meaning on its own, and it only works with restrictions. I
> >> don't know how to make this implementation better at the moment (it's
> >> still work in progress) but feel free to have a look.
> >>
> >> Kristian
> >
> > Really nice. Now we just need a pair of demos (C++/Python). :-)
>
> We need to do some work to have it functioning through PyDOLFIN. I think
> the PyDOLFIN FunctionSpace needs to be extended. Any ideas Johan?

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

> Garth
>
> > --
> > Anders
> >
> >
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