dolfin team mailing list archive

["Martin Sandve Alnæs" <martinal@xxxxxxxxx>]

On Wed, Dec 17, 2008 at 6:35 PM, Anders Logg <logg@xxxxxxxxx> wrote:
> On Wed, Dec 17, 2008 at 06:08:14PM +0100, Johan Hake wrote:
>> On Wednesday 17 December 2008 17:54:23 Martin Sandve Alnæs wrote:
>> > On Wed, Dec 17, 2008 at 5:42 PM, Johan Hake <hake@xxxxxxxxx> wrote:
>> > > On Wednesday 17 December 2008 16:34:16 Anders Logg wrote:
>> > >> On Wed, Dec 17, 2008 at 01:58:35PM +0100, Martin Sandve Alnæs wrote:
>> > >> > Using latest hg versions of everything, I'm trying to plot a Function
>> > >> > from C++ based on a SFC-generated function space and I get:
>> > >> >
>> > >> > Failed to read DOLFIN mesh or function XML file for plotting:
>> > >> >   *** Error: Unable to find dof map in library:
>> > >> > "FiniteElement('Lagrange', 'triangle', 1)".
>> > >> > Unable to plot (DOLFIN Python module or Viper plotter not available).
>> > >> >
>> > >> > Can I suggest using Function::interpolate to make a .vtu file to plot
>> > >> > instead of relying on a form compiler specific precompiled element
>> > >> > library?
>> > >> >
>> > >> > Martin
>> > >>
>> > >> Sounds like a good idea. We now generate Python script that loads the
>> > >> Function (or Mesh) from file and then calls Viper from Python.
>> > >>
>> > >> Does Viper support direct plotting of .vtu files? In that case, we
>> > >> would not need to call Python from C++. We could generate a .vtu file
>> > >> and then call Viper with that file (using system()).
>> > >>
>> > >> I don't have time to fix this now, so either find someone to fix it or
>> > >> put it on the TODO list.
>> >
>> > What is in use, the text file or bugzilla?
>> >
>> > > We could also plot a cpp.Function instead of a dolfin.Function. That fix
>> > > would not be so extensive. I had a brief look at it but couldn't find out
>> > > where
>> > >
>> > >   Function(filename)
>> > >
>> > > was called.
>> > >
>> > > Johan
>> >
>> > I also want to write a Function to file in C++.
>> > What are the requirements on the FunctionSpace
>> > to be able to do that?
>>
>> I think that the only requirement is that the element should be defined in
>>
>>   dolfin/elements/elements.py
>
> That should only be required for reading.

That's probably what I want.

The strings there use "triangle" instead of 'triangle' which is what
repr("triangle") returns. This doesn't match with the UFL
implementation of repr(element), and this is where my current attempt
failed.

Even when this is fixed, one way or the other, this element library is
ffc specific. I don't know exactly how compatible the dofmaps from ffc
and sfc are, and I'm not sure how to fix this...

Martin