Ola Skavhaug wrote: > > > On Wed, Aug 13, 2008 at 2:57 PM, Johan Hoffman <[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]>> wrote: > > > > > > > Johan Hoffman wrote: > >>> > >>> Anders Logg wrote: > >>>> On Tue, Jun 17, 2008 at 02:45:41PM +0100, Garth N. Wells wrote: > >>>>> It would be useful to lay out a plan for tackling DofMaps. > Getting > >>>>> this > >>>>> right is the key to parallel assembly, assembly > optimisations and > >>>>> applying Dirichlet boundary conditions by eliminating > Dirichlet dofs > >>>>> from the global system. > >>>>> > >>>>> I'm happy to take a look, but I'll need some time because > I've lost > >>>>> my > >>>>> overview of DofMaps. If someone else is already on top of > it, I'd be > >>>>> happy to provide feedback. > >>>>> > >>>>> Garth > >>>> I won't have time to look at it until after the summer and I > haven't > >>>> started. > >>>> > >>>> Anyway, I think we should wait until after the next release > until we > >>>> start messing with the dof maps. > >>>> > >>>> Are there any issues we need to sort out before releasing > 0.8? I'm > >>>> thinking about a new release some time this or next week. > >>>> > >>>> One is to fix the bug in DirichletBC, but other than that? > >>>> > >>> Now would be a good time for a release so I can start messing with > >>> DofMaps. > >>> > >>> Garth > >> > >> Has anything more been done about the DofMap design? During the > summer > >> Niclas has extended to general elements his adaptive algorithm for > >> distributed parallel computing, so we are now ready to start > messing > >> with > >> the DofMaps in order to implement his algorithm in DOLFIN. > >> > > > > It has been given some thought, but no changes have been made in the > > code yet. > > Ok. Any threads on the list to point to where this is discussed? > > If you have something already, I would suggest making it > > publicly available somewhere for feedback before starting work > on DOLFIN. > > It is a refinement and generalization of the thesis work of Niclas > Jansson > which was discussed on the list before the summer. Is is outlined > in his > report: > > http://www.nada.kth.se/utbildning/grukth/exjobb/rapportlistor/2008/rapporter08/jansson_niclas_08051.pdf > > My announcement here was to initiate a discussion of the detailed > implementation, and to check if other DOLFIN-people were working on > similar stuff to avoid double/conflicting development. > > /Johan > > > Very good. We were about to start on this task, so now a good point in > time to join forces. > As a starting point, it would be nice to agreeing on what data is > needed in addition to the partitioned meshes to construct the global > dofmap. I.e. which MeshFunctions to construct during the mesh > paritioning process. Are you people using the same {T,S,F} input as > Anders describes in Algorithm 5 in his paper? > > > Ola
No, we use a set of MeshFunctions marking ghosted/shared vertices. However, the algorithm is almost the same. Input: Distributed mesh T 1) extract interior boundary I of T (boundary between processors). 2) iterate over I and decide which processor should renumber which shared dof. 3) compute offset_i for each processor i. 4) renumber all dofs on processor i starting from offset_i (local + (assigned) shared). 5) exchange assigned numbers for shared dofs. Niclas > > > > > > > Garth > > > > > >> I see Anders report referenced in the code, where the mapping > scheme > >> described is fairly close to what Niclas has implemented, > although there > >> are some differences. We will sit down today to sum up what we > think > >> needs > >> to be done, and then we can discuss this on the mailing list. > >> > >> /Johan > >> > >> > >> > >> > >> > >> > >> > >> > > > > > > _______________________________________________ > > DOLFIN-dev mailing list > > [email protected] <mailto:[email protected]> > > http://www.fenics.org/mailman/listinfo/dolfin-dev > > > > > _______________________________________________ > DOLFIN-dev mailing list > [email protected] <mailto:[email protected]> > http://www.fenics.org/mailman/listinfo/dolfin-dev > > > > > -- > Ola Skavhaug _______________________________________________ DOLFIN-dev mailing list [email protected] http://www.fenics.org/mailman/listinfo/dolfin-dev
