ufl team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Thu, Nov 01, 2007 at 09:00:05AM +0100, kent-and@xxxxxxxxx wrote:
> > 2007/11/1, Anders Logg <logg@xxxxxxxxx>:
> >> On Tue, Oct 30, 2007 at 09:57:18AM +0100, Martin Sandve Alnæs wrote:
> >> > 2007/10/29, Anders Logg <logg@xxxxxxxxx>:
> >> > > On Fri, Oct 26, 2007 at 01:23:11PM +0200, Kent-Andre Mardal wrote:
> >> > > > fre, 26.10.2007 kl. 12.09 +0200, skrev Martin Sandve Alnæs:
> >> > > > > Den 25.10.07 skrev kent-and@xxxxxxxxx <kent-and@xxxxxxxxx>
> >> følgende:
> >> > > > > > geometry_element = FiniteElement("Hermite", "triangle", 3)
> >> > > > > > uknown_element = FiniteElement("Lagrange", "triangle", 1,
> >> geometry_element)
> >> > > > >
> >> > > > > Eller:
> >> > > > >
> >> > > > > cell = Cell(polygon, mapping="affine", order=1)
> >> > > > > cell = Cell("triangle")
> >> > > > > cell = Cell("triangle", "affine")
> >> > > > > cell = Cell("triangle", "Hermite", 3)
> >> > > > > cell = Cell("triangle", "isoparametric", 2)
> >> > > > >
> >> > > > > element = FiniteElement("Lagrange", cell, 1)
> >> > > > > element = FiniteElement("Hermite", cell, 3)
> >> > > >
> >> > > > What we typically do is that we define the global element in terms
> >> of a
> >> > > > mapped reference element (as we know this is not always a smart
> >> thing to
> >> > > > do cf. the Rannacher-Turek element).
> >> > > >
> >> > > > Anyway, we could then have
> >> > > >
> >> > > > reference_element = ReferenceElement("Lagrange", "triangle", 3)
> >> > > >
> >> > > > mapping = Mapping("isoparametric", 3)
> >> > > >
> >> > > > global_element = FiniteElement(reference_element, mapping)
> >> > > >
> >> > > >
> >> > > > Here Mapping could be e.g. affine, Piola, isoparametric, Hermite
> >> > > >
> >> > > >
> >> > > > The short cut can be
> >> > > >
> >> > > > fe = FiniteElement("Lagrange", "triangle", "affine", 3)
> >> > >
> >> > > Looks good to me, but it would be good to have the mapping as the
> >> last
> >> > > argument (so it could be left out when using the default mapping).
> >> > >
> >> > > /Anders
> >> >
> >> > The backside is that we must use FiniteElement.__init__(self, *args,
> >> > **kwargs) to enable different constructor arguments in Python, I'm not
> >> > a big fan of that. It would be nice to avoid that if we can.
> >>
> >> Why? Isn't it enought do do
> >>
> >>   def __init__(family, shape, degree, mapping="affine"):
> >>       ...
> >>
> >> /Anders
> >
> >
> > This doesn't fit into that exactly:
> >
> >> > reference_element = ReferenceElement("Lagrange", "triangle", 3)
> >> > mapping = Mapping("isoparametric", 3)
> >> > global_element = FiniteElement(reference_element, mapping)
> >
> >
> 
> OK, I think
> 
> cell = Cell(polygon, geometry="Lagrange", order=1)
> element = FiniteElement("Lagrange", cell, 1, geometry_mapping="affine")

It seems more natural to put the information about the type of mapping
in the mapping argument. It looks like it's now in two places (cell
and geometry_mapping)?

/Anders

> is sufficient.
> 
> We need the geometry_mapping parameter in addition to cell.
> 
> 
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