I was a bit quick there, the two names Q/S do of course carry information
beyond the cell being different from the P cases. Can we perhaps make an
alias Lagrange -> P/Q (DP/DQ for degree 0)?


A couple of UFL implementation sidenotes:

All aliases should be applied in UFL just as we do today with short/long
names, not in the form compiler, otherwise the form signatures will differ
depending on what names you use.

If we deprecate (some of) the old names, the deprecation period should be
long because this touches a lot of code and keeping old aliases does not
carry any real cost to code maintenance.

Martin


On 3 March 2014 12:04, Anders Logg <[email protected]> wrote:

> Both these options could be handled:
>
> - Allow r = 0 for P elements and handle the switch from continuous to
>   discontinuous inside the form compiler, which will anyway need a lot
>   of if-else checking since many of the names are different in FIAT.
>
> - Introduce shortcuts in some cases, but note that both the "Q" elements
>   and the "S" elements are essentially different from the "P" elements
>   so it doesn't make sense that "P" should work for all of them. In the
>   case of discontinuous elements, we would need to introduce an alias
>   for "DP" --> "DPC".
>
> --
> Anders
>
>
> On Mon, Mar 03, 2014 at 12:30:50PM +0100, Garth N. Wells wrote:
> >
> > On 3 Mar 2014, at 12:09, Martin Sandve Alnæs <[email protected]> wrote:
> >
> > > I prefer the second option here over the first.
> > >
> > > But I don't like not being able to switch between (continuous)
> piecewise linear and piecewise constant elements with just the degree.
> There's a lot of code snippets a'la 'family = lamda degree: "DG" if degree
> == 0 else "CG"' around in user code.
> > >
> >
> > Agree. This can be annoying.
> >
> > > For similar reasons, I don't like having to select e.g. P,Q,S
> depending on the cell type, when we already have the cell type specified
> otherwise. That will make writing mesh-type independent code more difficult
> when we get support for quads.
> > >
> >
> > Agree.
> >
> > Garth
> >
> > > I'm pretty sure a family alias which maps to P/Q/S depending on the
> cell for degree>0 and DP/DQ/DS for degree==0 would quickly become the most
> popular one.
> > >
> > > Martin
> > >
> > >
> > > On 3 March 2014 09:47, Anders Logg <[email protected]> wrote:
> > > I would like the names to be as consistent with the poster as
> > > possible. After all, we are printing the UFL names in the poster next
> > > to the element names.
> > >
> > > I see two options:
> > >
> > > 1. Either we keep the UFL names as suggested:
> > >
> > > P   dP
> > > P   RTe/RTf     dP
> > > P   N1e         N1f   dP
> > >
> > > P   dP
> > > P   BDMe/BDMf   dP
> > > P   N2e         N2f   dP
> > >
> > > Q   dQ
> > > Q   RTce/RTcf   dQ
> > > Q   Nce         Ncf   dQ
> > >
> > > S   dPc
> > > S   BDMce/BDMcf dPc
> > > S   AAe         AAf   dPc
> > >
> > > 2. Or, as suggested but all uppercase:
> > >
> > > P   DP
> > > P   RTE/RTF     DP
> > > P   N1E         N1F   DP
> > >
> > > P   DP
> > > P   BDME/BDMF   DP
> > > P   N2E         N2F   DP
> > >
> > > Q   DQ
> > > Q   RTCE/RTCF   DQ
> > > Q   NCE         NCF   DQ
> > >
> > > S   DPC
> > > S   BDMCE/BDMCF DPC
> > > S   AAE         AAF   DPC
> > >
> > > I think I would vote for the second option.
> > >
> >
>
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