ufl team mailing list archive

[Martin Sandve Alnæs <martinal@xxxxxxxxx>]

On Fri, Feb 13, 2009 at 11:53 AM, Kristian Oelgaard
<k.b.oelgaard@xxxxxxxxxx> wrote:
>
>
> Hello,
>
> Any thoughts on how to implement a better rule for determining the polynomial
> order of a form?
>
> as it is now the forms:
>
> a = v*u*dx
> a = f*v*u*dx
> a = f*f*f*.....*v*u*dx
> a = inner(grad(v), grad(u))*dx
>
> all result in the same order (2 for linear basis functions)

What do we want? Add the degrees of all functions and basis functions
that are multiplied? Should be possible to do.

> Also, what is the strategy for handling the form
>
> a = (inner(grad(v), grad(u)) + v*u)*dx ?
>
> will the order of the form be determined by the highest order, or will it be
> possible to split the integrand according to order? The latter could get
> complicated for forms like:
>
> a = f*(inner(grad(v), grad(u)) + v*u))*dx

If I got it right, lhs and rhs can handle splitting of arbitrary forms by arity,
so it should be possible to do the same for terms with different order.

> I do notice the # TODO in formdata.py, I'm just curious.
>
> Kristian

Note that I use the convention
FIXME: High priority issue
TODO: Low priority issue

Since this obviously can be postphoned until after we get things
working in general.

Martin