dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Thu, Apr 05, 2007 at 10:45:35AM +0200, Garth N. Wells wrote:
> 
> 
> Anders Logg wrote:
> > So, the new UFC-based assembly seems to be mostly complete and I think
> > we've reached a point where we need to break everything in order to
> > finish up.
> > 
> > This should be the last major rewrite we do for a while. We've done
> > quite a few, but not needing to do another one soon is the whole point
> > of the UFC interface.
> > 
> > Where should we do this? We can do it in dolfin-dev (dolfin), or we
> > can set up a separate branch. Doing it in dolfin-dev would be the most
> > practical, since we will need to touch the code in quite a few places
> > to get things done.
> > 
> > Meanwhile, we have dolfin-stable for those who need something that
> > works. (We should write something in the wiki about this!)
> > 
> > Here's a summary of what we have and what we need to do:
> > 
> > - The new UFC-based assembly has been implemented in the class
> > Assembler and is mostly finished.
> > 
> > - There is a small test program in src/sandbox/assembly.
> > 
> > - We've been able to remove quite a lot of code. As mentioned before,
> > Assembler.cpp is (still) considerably shorter than FEM.cpp.
> > 
> > - A whole lot of code can be removed from the Function classes. For
> > example, here is what the implementation of UserFunction looks like:
> > 
> >   void UserFunction::interpolate(real* coefficients,
> >                                  const ufc::cell& cell,
> >                                  const ufc::finite_element& finite_element)
> >   {
> >     for (uint i = 0; i < finite_element.space_dimension(); i++)
> >       coefficients[i] = finite_element.evaluate_dof(i, *this, cell);
> >   }
> > 
> > And here is what the implementation of DiscreteFunction looks like:
> > 
> >   void NewDiscreteFunction::interpolate(real* coefficients,
> >                                         const ufc::cell& cell,
> >                                         const ufc::finite_element& finite_element)
> >   {
> >     dof_map->tabulate_dofs(dofs, cell);
> >     x.get(coefficients, dof_map->local_dimension(), dofs);
> >   }
> > 
> > - The class NewDiscreteFunction will replace DiscreteFunction and I
> > would like us to try hard to avoid trying to make too much of it. In
> > particular, it owns all its data (except for the mesh which is a
> > reference) so we don't need to mess with smart pointers or tracking
> > who owns the vector etc.
> > 
> 
> Any problem adding a function to DiscreteFunction which returns the 
> DofMap? For I/O, I need to get the mesh (which I can get from DofMap).
> 
> Garth

I might have an objection to this. I need to run now but will get
back tonight and say more.

/Anders


> > - A lot of classes will be removed: BilinearForm, LinearForm,
> > Functional, FEM, FiniteElement, FiniteElementSpec, AffineMap.
> > 
> > - A lot of classes will need to be updated: PDE, LinearPDE,
> > NonlinearPDE, all the modules, most of the demos.
> > 
> > - The new assembler has not been merged with Garth's parallel
> > assembler, but now may be the time.
> > 
> > - All help appreciated...
> > 
> > Any last words before I start taking things apart?
> > 
> > /Anders
> > _______________________________________________
> > DOLFIN-dev mailing list
> > DOLFIN-dev@xxxxxxxxxx
> > http://www.fenics.org/mailman/listinfo/dolfin-dev
> > 
> 
> 
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