On Tue, Dec 7, 2010 at 21:31, Dmitry Karpeyev <dkarpeev at gmail.com> wrote:
> I actually prefer the model where a geometric object (e.g., a DA) controls > the restriction (e.g., DAGlobalToLocalBegin, etc). Okay, but does the user need to use something like DMSliced just to update a local form? Things like VecView already need a way to follow an upward link to a DM. There is a delicate issue of circular dependencies if _p_Vec was given a slot for the DA. On the one hand, I feel like it would be cleaner if every Vec had a link to _some_ DM, which, as far as the Vec is concerned, is just a "function space". The default implementation would be flat Cartesian space. On the other hand, it makes a dependency loop unless you always pass pairs (DM,Vec) around (ugly and weird), or (a very limited subset of) the DM API becomes part of the Vec "package". -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20101207/b25e2069/attachment.html>
