dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

Marie Rognes wrote:
> Anders Logg wrote:
> > I've thought some more on the problem of mesh refinement and updating
> > of Functions.
> >
> > The main problem seems to be the following:
> >
> >   mesh.refine()
> >
> > If we want to allow this, then we need to provide some kind of
> > automated updating of functions and function spaces to the new mesh,
> > since this call will otherwise destroy all function spaces and
> > functions that refer to that mesh:
> >
> >   V = FunctionSpace(mesh, "CG", 1)
> >   v = Function(V)
> >   mesh.refine() # V and v no longer make any sense
> >
> > This gives us two options. Either we disallow refinement of a mesh
> > without making a copy. Or we provide automated updating. I think we
> > should do the latter.
> >
> >   
>
> I think that I would appreciate both:
>
> (a) Automated updating if mesh.refine()
>
> and
>
> (b) Functionality provided for updating functions to a new mesh if mesh 
> = refine(mesh)

Agree.

> > What is needed compared to what we have now is to let a call to
> > Mesh::refine trigger a call to FunctionSpace::update for all function
> > spaces defined on the mesh, which in turn will trigger calls to
> > Function::update for all functions defined on the function spaces.
> >
> > We can make the update functions private.
> >
> > Comments or objections? I think I can make this work.
> >
> >   
>
> I can imagine that one would like to keep a copy of a function on the 
> old mesh if
> one compares solutions from different meshes. Then automated updating could
> be somewhat suboptimal.

It's essential that one can allow some functions to remain defined on 
one mesh while others are updated to the new mesh.

Garth

> --
> Marie
>
>
>
> > --
> > Anders
> >   
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> >
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