dolfin team mailing list archive

[Johan Hake <hake@xxxxxxxxx>]

On Monday 30 June 2008 16:55:39 Johan Hake wrote:
> On Monday 30 June 2008 16:27:51 Johan Hake wrote:
> > On Monday 30 June 2008 13:28:11 Martin Sandve Alnæs wrote:
> > > 2008/6/30 Anders Logg <logg@xxxxxxxxx>:
> > > > On Mon, Jun 30, 2008 at 12:50:39PM +0200, Martin Sandve Alnæs wrote:
> > > >> 2008/6/28 Anders Logg <logg@xxxxxxxxx>:
> > > >> > On Sat, Jun 28, 2008 at 08:55:44PM +0200, Johan Hake wrote:
> > > >> >> Hello!
> > > >> >>
> > > >> >> I tried to compile an advection diffusion form using Streamline
> > > >> >> Upwind Petrow Galerkin stabilazing method, similar to the one
> > > >> >> introduced in DOLFIN 0.6.4. Using 3 dimensional and first degree
> > > >> >> Lagrange elements, FFC/g++ chokes when the produced code is
> > > >> >> compiling. It wont finish compile... Is this a known problem and
> > > >> >> a limitation of FFC/g++?
> > > >> >
> > > >> > Try compiling with the -r quadrature option. I guess this is not
> > > >> > supported in the JIT compiler yet, but could easily be added.
> > > >> > There should be an option
> > > >> >
> > > >> >  dolfin_set("form representation", "quadrature");
> > > >> >
> > > >> > in the same way as there is an option "optimize". See if you can
> > > >> > figure it out and send a patch, or else file a bug report.
> > > >> >
> > > >> > Options are added in DefaultParameters.h in DOLFIN and the JIT
> > > >> > compiler is in jit.py in FFC.
> >
> > The jit compiler allready a kwarg for the representation. The only thin I
> > had to add was a dolfin_set("form representation",value). The value of
> > this parameter is checked if an uncompiled form is sent to the assemble
> > function. The value is then just passed to jit, without checkes. I also
> > added a dolfin_set("quadrature points",value) which is also just passed
> > to the jit compiler.
>
> Sorry for the unconsistent english, I need vacation...
>
> > The changes is only done in the python interface, i.e., in assemble.py.
> > Maybee you freek on this Anders? I thought the changes would not have any
> > meaning for the c++ interface and therefore I did not add the parameters
> > in DefaultParameters.h.
> >
> > > >> > Possible options for "form representation" are "tensor",
> > > >> > "quadrature" and (unsupported at the moment) "symbolic" (for
> > > >> > SyFi).
> >
> > As it is now ffc check if the string is "tensor" if not it assume it is
> > quadrature. A more thorough check would be nice.
> >
> > > >> > The quadrature representation generates much less code than the
> > > >> > tensor representation.
> >
> > It did, and it compiled nicely!
>
> but the form is placed in the present directory, not in $HOME/.ffc/cache

Well it turned out that they _were_ placed in the ffc-cache. Sorry for the 
needless emails. Another reason for vacation :)

Johan

> Anyone know why?
>
> Johan
>
> > > >> SFC also does quadrature (in fact most users (me) mainly use that),
> > > >> and there are many possible compilation options. I don't think it's
> > > >> a good idea to mix form compiler details into dolfin. We should talk
> > > >> about this to find a solution that doesn't discriminate form
> > > >> compilers
> > > >>
> > > >> :-)
> > > >
> > > > I think we need have to. It is DOLFIN that sends the form to the form
> > > > compiler so DOLFIN needs to make a choice which form compiler to use.
> > > >
> > > > But I agree we should not discriminate form compilers. Any form
> > > > compiler that handles UFL/UFC should be possible to use.
> > >
> > > Then we should at least have an options system that doesn't
> > > need every possible form compiler option pre-registered.
> > >
> > > And setting form compiler options globally for all jit calls may not
> > > be enough, different forms may call for different compilation options.
> > >
> > > As I see it, dolfin doesn't need to know more than the option "form
> > > compiler". Compiler-specific options should be applied to the
> > > particular compiler.
> > >
> > > Like:
> > > dolfin_set("form compiler", "ffc")
> > > ffc_set("form representation", "quadrature")
> > > A = assemble(ufl_form, ...)
> > >
> > > or:
> > > dolfin_set("form compiler", "sfc")
> > > A = assemble(ufl_form, ..., options=sfc_options_dict)
> >
> > I like this.
> >
> > For now one could just get around all this parameter settings by just
> > send a precompiled form to assemble. I assume that this is what you do
> > Martin?
> >
> > Johan
> >
> > > --
> > > Martin
> > > _______________________________________________
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> > > DOLFIN-dev@xxxxxxxxxx
> > > http://www.fenics.org/mailman/listinfo/dolfin-dev
>
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