dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Fri, Nov 30, 2007 at 12:55:30PM +0000, Garth N. Wells wrote:
> 
> 
> Anders Logg wrote:
> > Magnus has done some initial work on implementing the missing
> > functions in MPIMeshCommunicator for broadcasting Mesh and
> > MeshFunction. (It seems to work but we need to clean it up a bit
> > before pushing.)
> >
> 
> Any idea when it will be pushed? I was just starting to look at it, so 
> I'll wait but don't want to wait too long and lose my enthusiasm.
> 
> 
> > To get further, we need to decide how to handle the parallel dof maps.
> > There is a class PdofMap in the sandbox. What does this do? (Garth)
> > 
> 
> It rearranges to dof map based on the mesh partition. From memory,
> dofs belong to process 0 are numbered 0 -> m, dofs belonging to process 
> 1 are number m+1 -> n, etc.

ok, simple enough.

> > Should we clean it up and add it to the library? (And should we name
> > it pDofMap?)
> >
> 
> First step is to restrict the appearance of ufc::dof_map to the class 
> dolfin::DofMap. Hopefully we can get everything into DofMap and won't 
> need pDofMap.

Let's hope so.

> During the initial development, it might be useful to have pDofMap and 
> pAssembler.

Sounds good.

-- 
Anders


> 
> > Also, how should we handle the selection between 
> > 
> >     MatCreateSeqAIJ
> > 
> > and
> > 
> >     MatCreateMPIAIJ
> > 
> > in PETScMatrix? My suggestion would be to just add a simple check in
> > the constructors, something like
> > 
> >     if (MPIManager::numProcesses() > 1)
> >       MatCreateMPIAIJ()
> >       ...
> >     else
> >       MatCreateSeqAIJ()
> > 
> 
> Sounds ok, although the initialisation of parallel matrices does require 
> more information than sequential matrices (global size, local size, etc).
> 
> Garth
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