On Tue, 8 Feb 2011, Derek Gaston wrote: > If there were a generic way to "connect" two dofs that aren't > geometrically connected.... I think all of this would take care of > itself. Then the send_list could get populated correctly.... > sparsity patterns could get calculated properly....
Sparsity patterns... that would be the first obvious failure point that Ben and I missed. > and ghosted elements in ParallelMesh could be handled automatically. > > I would be willing to take a shot at implementing such a thing if we > can decide on where it should go. Not just "where it should go" but "what the heck it is". If you want a fully *generic* way of representing any possible pattern of connections between dofs, you've just effectively added a whole new SparseMatrix to the library. If there's any *specific* enumeration of types of connectivity (e.g. the current distinction between DofMap::use_coupled_neighbor_dofs == false/true) then there's a possibility to be much more efficient. > A quick question while we're on the subject. How does ParallelMesh > decide what to ghost? Is it based on the stencil? Is there a > similar way to the send_list to add more elements to the list that > is ghosted? I just haven't looked at ParallelMesh yet... It's just based on the topology - each processor has its local elements, any elements that share nodes with its local elements, and any ancestors (but not necessarily siblings/cousins) of any of the above. Basically the minimum necessary to give you a patch around any local element's node and to understand the AMR tree. --- Roy ------------------------------------------------------------------------------ The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio XE: Pinpoint memory and threading errors before they happen. Find and fix more than 250 security defects in the development cycle. Locate bottlenecks in serial and parallel code that limit performance. http://p.sf.net/sfu/intel-dev2devfeb _______________________________________________ Libmesh-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-devel
