On Wed, Feb 8, 2012 at 08:57, Matthew Knepley <[email protected]> wrote:
I just want to point out that Jed envisions that coefficients (and maybe subproblems, etc) cannot be accommodated on the same DM. I agree. However, this silly idea that we can make DMs all over the place with no cost, like DAs, if they contain all the mesh information, is just wrong. I think this is a good argument for having both a topology object and a DM handling layout/solver information. What is the counter-argument?
Why can't we have multiple DMs that internally share topology? Then each implementation can share or not share as much as they like. Some DMs might also share topological information between levels. I don't think it makes sense to encode a specific sharing model into the type system.