dolfin team mailing list archive

["Matthew Knepley" <knepley@xxxxxxxxx>]

On 3/4/07, Garth N. Wells <g.n.wells@xxxxxxxxxx> wrote:
> Quoting Anders Logg <logg@xxxxxxxxx>:
>
> > On Fri, Mar 02, 2007 at 05:19:43PM +0100, Garth N. Wells wrote:
> > >
> > >
> > > Anders Logg wrote:
> > > > A first version of the new UFC-based assembly is now implemented.
> > > > A bunch of features are still missing, but we can now assemble the
> > > > bilinear form for Poisson's equation and get correct results... :-)
> > > >
> > > > Here are some notes if anyone wants to dig in. For example, it might
> > > > be a good idea to start thinking of merging in the parallel assembler
> > > > at this point.
> > > >
> > >
> > > Are there any short-term plans to work on partitioning of the mesh and
> > > distributing the mesh data across processors? This is where the real
> > > work is for parallel assembly and solve.
> > >
> > > Garth
> >
> > Yes, I have a student working on mesh partitioning in DOLFIN and we
> > will start adding parts of it in a while, but I can't promise when it
> > will be ready. The parallel assembly/distribution will probably be
> > implemented before the partitioning has been implemented (and until
> > then we can rely on METIS).
> >
>
> Might be worth considering SCOTCH
>
>   http://www.labri.fr/perso/pelegrin/scotch/
>
> rather than implementing a partitioning algorithm. Unlike METIS, SCOTCH is
> released under GPL.

The thing that METIS has over Scotch, Jostle, and Chaco is better handling
of the objective function. It is MUCH better at load balancing due to the
complicated multiobjective you want to have. Zoltan is a nice hypergraph
partitioner, which seems to work even better than graph partitioning for
load balancing. I have recently incorporated this into PETSc.

 Matt

> Garth
>
> > /Anders
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