ffc team mailing list archive

[Kristian Oelgaard <k.b.oelgaard@xxxxxxxxx>]

On 26 March 2010 13:36, Andy Ray Terrel <aterrel@xxxxxxxxxxxx> wrote:
> Could you have ffc print out a warning so dumb users like me will
> remember this change when their code breaks?

That might be a good idea, would it be enough to put in the __add__ operator in UFL for FiniteElements?
We didn't use __mul__ before so we don't have to put a waring in there although we could do that.
Then after a few releases we can remove the warnings again, once the dumb users have gotten used to the new syntax. :)

Kristian

> -- Andy
>
> On Mon, Mar 22, 2010 at 1:14 PM, Marie Rognes <meg@xxxxxxxxx> wrote:
> > Anders Logg wrote:
> > > On Mon, Mar 22, 2010 at 01:43:41PM +0100, Marie Rognes wrote:
> > >
> > > > Marie Rognes wrote:
> > > >
> > > > > Anders Logg wrote:
> > > > >
> > > > > > On Mon, Mar 22, 2010 at 11:41:42AM +0100, Marie Rognes wrote:
> > > > > >
> > > > > > > Anders Logg wrote:
> > > > > > >
> > > > > > > > On Mon, Mar 22, 2010 at 06:20:00PM +0800, Garth N. Wells wrote:
> > > > > > > >
> > > > > > > > > On 22/03/10 16:42, Kristian Oelgaard wrote:
> > > > > > > > >
> > > > > > > > > > On 21 March 2010 21:32, Anders Logg <logg@xxxxxxxxx> wrote:
> > > > > > > > > >
> > > > > > > > > > > After Marie's latest addition of enriched spaces (and
> > > > > > > > > > > some discussion
> > > > > > > > > > > with Doug Arnold), it seems clear that our current
> > > > > > > > > > > notation V + W for
> > > > > > > > > > > mixed spaces is not optimal.
> > > > > > > > > > >
> > > > > > > > > > > Even though one may think of the operation of creating a "mixed
> > > > > > > > > > > function space" as a direct sum,
> > > > > > > > > > >
> > > > > > > > > > > X = {(v, 0) : v in V} \oplus {(0, w) : w in W},
> > > > > > > > > > >
> > > > > > > > > > > it is more natural (and common) to think of it as a
> > > > > > > > > > > Cartesian product,
> > > > > > > > > > >
> > > > > > > > > > > X = V \times W = {(v, w) : v in V, w in W}
> > > > > > > > > > >
> > > > > > > > > > > It would therefore be more natural to use '*' instead of '+' as
> > > > > > > > > > > the
> > > > > > > > > > > operation for creating mixed elements/function spaces.
> > > > > > > > > > >
> > > > > > > > > > > That would free up '+' to be used for enriched spaces (which have
> > > > > > > > > > > recently been added),
> > > > > > > > > > >
> > > > > > > > > > > X = {v + w : v in V, w in W}
> > > > > > > > > > >
> > > > > > > > > > > The typical example would be to take V piecewise
> > > > > > > > > > > linears and W scaled
> > > > > > > > > > > P3 bubbles.
> > > > > > > > > > >
> > > > > > > > > > > In summary, the suggestion is to use the following notation:
> > > > > > > > > > >
> > > > > > > > > > > + <-->  +
> > > > > > > > > > > * <-->  \times
> > > > > > > > > > >
> > > > > > > > > > > It's obvious this is better than what we have now which is
> > > > > > > > > > >
> > > > > > > > > > > + <--> \oplus
> > > > > > > > > > > ? <--> +
> > > > > > > > > > >
> > > > > > > > > > > Thoughts?
> > > > > > > > > >
> > > > > > > > > > Agree.
> > > > > > > > >
> > > > > > > > > Me too.
> > > > > > > > >
> > > > > > > > > Garth
> > > > > > > >
> > > > > > > > ok. Let's change then.
> > > > > > > >
> > > > > > > > It will require changes in both UFL and FFC. Anyone up for it?
> > > > > > >
> > > > > > > I can fix ffc.
> > > > > >
> > > > > > I was hoping for that. :-)
> > > > > >
> > > > > >
> > > > > > > (Have no permission for ufl)
> > > > > >
> > > > > > You do now. ;-)
> > > > >
> > > > > Aka, I'll fix that too.
> > > >
> > > > Fixed:
> > > >
> > > > (a) ElementUnion is now called EnrichedElement.
> > > >
> > > > (b) (Old) V + Q --> (New) V * Q
> > > >
> > > > (c) V + Q = EnrichedElement(V, Q)
> > > >
> > > >
> > > > Now, PYDOLFIN needs updating...
> > >
> > > Done.
> >
> >
> > Great! (I'm off to do some Mini debugging.)
> >
> > --
> > Marie
> >
> > _______________________________________________
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