dolfin team mailing list archive

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

On Mon, 2010-08-09 at 15:32 +0200, Ola Skavhaug wrote:
> Hi,
> 
> when running DOLFIN in parallel, data reduction would be a nice thing
> to have. Typically, it would be good to have something like this:
> 
> mesh = UnitSquare(2000, 2000)
> reduced_mesh = UnitSquare(200, 200)
> 
> V = FunctionSpace(mesh, "CG", 1)
> reduced_V = FunctionSpace(reduced_mesh, "CG", 1)
> 
> u = Function(V)
> 
> ...
> 
> reduced_u = interpolate(u, reduced_V)
> f << reduced_u
> 
> However, the problem is that the automatic partitioning of the meshes
> constructs two different non-overlapping meshes on each local node. I
> really don't want to allow extrapolation in this case. I would be
> happy to contribute fixing this problem; does anybody see how to
> attack it?
> 

We just need to have the program handle correctly the case in which a
point is not found in the domain. It shouldn't be hard to fix (it may be
just a case of removing an error message ans stressing in the code
comment that points must reside on the same process).

Start by looking in the Function::interpolate functions.

Garth 


> Ola
>