dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Thu, Oct 08, 2009 at 01:02:43PM +0100, Garth N. Wells wrote:
>
>
> Anders Logg wrote:
> > On Wed, Oct 07, 2009 at 10:47:53AM +0100, Garth N. Wells wrote:
> >> We added some time ago
> >>
> >>    dof_map::max_local_dimension()
> >>
> >> and perhaps we also need
> >>
> >>    finite_element::max_local_dimension()
> >>
> >> and
> >>
> >>    finite_element::local_dimension(const ufc_cell& )
> >>
> >> I have a problem for which the number of dofs an element has can grow
> >> during a computation. You may say that this is then a different element,
> >> but that would make it hard to handle in DOLFIN and hard to generate
> >> code for.
> >>
> >> Here's an example of an inconsistency. In dolfin::Function, we
> >> initialise some scratch space for the dof map based on the element space
> >> dimension,
> >>
> >>    dofs = new uint[element.space_dimension()];
> >>    for (uint i = 0; i < element.space_dimension(); i++)
> >>      dofs[i] = 0;
> >>
> >> whereas is dolfin::UFC we use dof_map::max_local_dimension().
> >
> > Yes, it would be natural to have max_ in both and an optional cell
> > argument.
> >
> > But for the finite element class, it would be better to have
> >
> >   unsigned int max_space_dimension() const;
> >   unsigned int space_dimension(const cell& cell) const;
> >
> > rather than (max_)local_dimension, since there is always only one
> > dimension for an element (not local and global).
> >
>
> Yes, these names are what I intended.
>
> We should list things as Blueprints on Launchpad and pick a date on
> which to discuss what should and shouldn't be in the next UFC release.
> Otherwise things bounce around for a long time.
>
> Garth

I just added a copy of this discussion:

https://blueprints.launchpad.net/ufc/+spec/max-space-dimension-in-finite-element

I suggest we try to get closer to DOLFIN 1.0 and when we think we're
close enough, we take a round and look at which things we want to add
to UFC. It's probably good to wait and collect a bunch of changes
since it's a bit of a pain to update UFC (changes needed in both
DOLFIN and the form compilers, and the UFC manual).

We can then release DOLFIN 1.0 and UFC 2.0 at the same time.

--
Anders

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