ffc team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Wed, Jan 06, 2010 at 04:25:30PM +0100, Marie Rognes wrote:
> Anders Logg wrote:
> >We've come pretty far on the rewrite of FFC and only a few functions
> >remain. As far as I can see, it remains to implement code generation
> >for the following functions:
> >
> >Kristian:
> >
> >  code["evaluate_basis_all"] = not_implemented
> >  code["evaluate_basis_derivatives"] = not_implemented
> >  code["evaluate_basis_derivatives_all"] = not_implemented
> >
> >Marie:
> >
> >  code["tabulate_entity_dofs"] = not_implemented # Marie doesn't know what this function should do
>
>
> Evidently, my comment was unclear ;)
>
> Should it look like this for CG_1?
>
>  /// Tabulate the local-to-local mapping of dofs on entity (d, i)
>  virtual void tabulate_entity_dofs(unsigned int* dofs,
>                                    unsigned int d, unsigned int i) const
>  {
>       dofs[0] = i   }

Yes, this function should return an array of the dofs (dof indices) for
the dofs associated with entity number i of dimension d.

But perhaps we should check the d and the i as well to make sure that
d == 0 and i <= d + 1?

Here's another example of what should happen for P3 in 2D.

  switch (d)
  {
  case 0:
    if (i > 2)
      throw std::runtime_error("Sensible error message.");
    dofs[0] = i;
  case 1:
    if (i > 2)
      throw std::runtime_error("Sensible error message.");
    dofs[0] = 3 + 2*i;
    dofs[1] = 3 + 2*i + 1;
  case 2:
    if (i > 0)
      throw std::runtime_error("Sensible error message.");
    dofs[0] = 10;
  default:
    throw std::runtime_error("Sensible error message.");
  }

The corresponding function num_entity_dofs should return the size of
the dofs array for each dimension so it should return 0, 2 and 1 in
the above case for d = 0, 1, 2.

> >  code["tabulate_coordinates"] = not_implemented # Marie doesn't believe in this function
> >
>
>
> What should this function do for the integral moment dofs, where
> there are more than one point per dof?

I guess we need to throw an exception and think about possibly extending the
UFC interface with this extra information.

--
Anders


> >Marie or Kristian:
> >
> >  code["interpolate_vertex_values"] = not_implemented
> >
>
> Can fix.
>
>

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