dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Sun, Sep 27, 2009 at 09:02:50PM +0200, Johan Hake wrote:
> On Saturday 26 September 2009 23:19:23 Anders Logg wrote:
> > On Sat, Sep 26, 2009 at 04:16:49PM +0200, Johan Hake wrote:
> > > On Saturday 26 September 2009 00:07:46 Anders Logg wrote:
> > > > On Fri, Sep 25, 2009 at 11:56:03PM +0200, DOLFIN wrote:
> > > > > One or more new changesets pushed to the primary dolfin repository.
> > > > > A short summary of the last three changesets is included below.
> > > > >
> > > > > changeset:   7147:2f99c8fb3a96
> > > > > tag:         tip
> > > > > parent:      7146:1d18d2b95462
> > > > > parent:      7145:3f905e727c11
> > > > > user:        Anders Logg <logg@xxxxxxxxx>
> > > > > date:        Fri Sep 25 23:56:04 2009 +0200
> > > > > description:
> > > > > merge
> > > > >
> > > > >
> > > > > changeset:   7146:1d18d2b95462
> > > > > parent:      7143:98d357740635
> > > > > user:        Anders Logg <logg@xxxxxxxxx>
> > > > > date:        Fri Sep 25 23:55:55 2009 +0200
> > > > > files:       dolfin/fem/DofMap.cpp dolfin/fem/DofMap.h
> > > > > dolfin/function/FunctionSpace.cpp dolfin/function/FunctionSpace.h
> > > > > description:
> > > > > Add update() function to FunctionSpace and DofMap for use in adaptive
> > > > > mesh refinement.
> > > >
> > > > I've added a first iteration of a functionality we need to do
> > > > adaptivity. When a mesh is refined, we can't reassemble the forms
> > > > since the FunctionSpace does not know the mesh has changed.
> > > >
> > > > It is now possible to update the FunctionSpace (actually the DofMap)
> > > > by calling FunctionSpace::update.
> > > >
> > > > Example:
> > > > >>> from dolfin import *
> > > > >>> mesh = UnitSquare(3, 3)
> > > > >>> V = FunctionSpace(mesh, "CG", 3)
> > > > >>> print V.dim()
> > > >
> > > > 100
> > > >
> > > > >>> mesh.refine()
> > > >
> > > > No cells marked for refinement, assuming uniform mesh refinement.
> > > >
> > > > >>> print V.dim()
> > > >
> > > > 100
> > > >
> > > > >>> V.update()
> > > > >>> print V.dim()
> > > >
> > > > 361
> > > >
> > > > I'm not sure what the right way to handle this is. Perhaps we should
> > > > have FunctionSpace::refine which calls refine on the mesh and then
> > > > calls update.
> > >
> > > This will then only work for one FunctionSpace. Other FunctionSpaces
> > > defined on the same Mesh would not be updated.
> > >
> > > Would it be possible to store all FunctionSpaces associated with a Mesh
> > > in a
> > >
> > >   vector<FunctionSpace*>
> > >
> > > in the Mesh? Then let Mesh::refine iterate over the FunctionSpaces and
> > > call the FunctionSpace::update.
> > >
> > > This could be handle by adding something like:
> > >
> > >   mesh->register(*this);
> > >
> > > in the constructor of FunctionSpace and
> > >
> > >   mesh->deregister(*this);
> > >
> > > in the destructor of FunctionSpace.
> >
> > That could be an option. There might be some issues with constness etc
> > and we've made mistakes before when trying to be clever, but we could
> > try... :-)
>
> What is the policy of constness for the Mesh class. I see that there exists a
> const and a non-const constructor in for example the FunctionSpace and DofMap.
> It is not explicit for me when I construct a FunctionSpace using a const Mesh
> and when I am not.
>
> > We would then need to have
> >
> >   mesh::refine
> >     --> FunctionSpace::update
> >       --> DofMap::update
> >       --> Function::interpolate etc for all functions
> >
> > So a FunctionSpace would also need to have some functionality for
> > registering Functions.

I've implemented this. Everything should be in place but it currently
breaks (I haven't put a lot of effort into debugging yet).

Garth, take a look and see if it makes sense (FunctionSpace::refine).
Perhaps you can spot something.

--
Anders

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