On Fri, Jan 22, 2010 at 09:35:23AM +0100, Kristian Oelgaard wrote: > > > 2010/1/22 Anders Logg <[email protected]>: > >On Thu, Jan 21, 2010 at 11:26:47PM +0100, Anders Logg wrote: > >>The MetaData.ufl example is failing in the quadrature representation. > >> > >>Kristian, could you have a look and see what goes wrong. Then I can > >>continue to make the incremental/combined integral stuff work. > > > >On second thought, maybe we should skip the whole thing with having > >different representations inside the same tabulate_tensor function > >for the following reasons: > > > >1. It leads to complications in the code generation. > > Very true. > > >2. It probably doesn't make much difference since if quadrature is > >required for one part of an integral, then it is likely the cost is > >low for including the other terms inside the existing quadrature loop. > > True. > > >3. The situation will not arise often since UFL will anyway group > >terms with the same dx inside the same integral and then all will have > >the same representation. > > I'm not sure this is correct, if the metadata is different the integrals will > not be grouped.
That's correct. So it has an effect when someone explicitly wants to treat a term with a specific representation, but not when FFC tries to auto-select the representation for each term since then all the terms will have metadata "auto" and be grouped together. I still think we have a strong case for a simplification. Agree? > >So the cases where this is useful are rare (because of the UFL > >grouping), it won't give any speedup and it's complicated to > >implement... > > > >We will still have the possibility of different representations for > >integrals on different subdomains and for cell, interior and exterior > >facet integrals. > > Yes, and this is probably the case where one will use it the most anyway. > > >If this sounds ok, I can add some checks in analysis.py that force all > >UFL integrals that will be grouped as part of the same UFC integral to > >use the same representation. > > Yes, such that if any quadrature is present they will all be quadrature. > > >Btw, does quadrature handle different quadrature degree for different > >integrals that become part of the same tabulate_tensor? If not, we can > >force metadata to be the same for all integrals that belong together. > > I don't know how the meta data is set up now, but it used to be able to do: > > a = v*u*dx + inner(grad(v), grad(u))*dx --> > > loop ip range(4): > .... > > loop ip range(9): > .... > > Inside one tabulate_tensor() funtion. ok, if there are no objections, I can have a go at adding some checks for having the same metadata in all terms UFL integrals that correspond to the same UFC integral (same domain type and domain number). -- Anders
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