On Wed, Jun 15, 2011 at 1:47 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:
> > On Jun 14, 2011, at 8:45 PM, Matthew Knepley wrote: > > > On Wed, Jun 15, 2011 at 1:42 AM, Barry Smith <bsmith at mcs.anl.gov> wrote: > > > > On Jun 14, 2011, at 8:36 PM, Matthew Knepley wrote: > > > > > On Wed, Jun 15, 2011 at 1:20 AM, Barry Smith <bsmith at mcs.anl.gov> > wrote: > > > > > > On Jun 14, 2011, at 7:59 PM, Jed Brown wrote: > > > > > > > On Wed, Jun 15, 2011 at 02:53, Barry Smith <bsmith at mcs.anl.gov> > wrote: > > > > It seems we should provide a DMSDA that is built specifically for > staggered grids, with the correct number of "slots" in the correct > "locations", it would have appropriate grid hierarchies and > interpolation/restriction. Not terribly hard but a bit of basic plumbing > code. I would rather have this then try to "tack on" the current DA a bunch > more stuff. > > > > > > > > Yeah, though there are many different staggered discretizations so > this could end up being a big project. Not conceptually hard, just a lot of > code. DMDA is already not especially small. > > > > > > DMDA started out small. DMSDA will start out small :-) > > > > > > Actually before we do DMSDA we probably should do a code review of DM, > then of DMDA and slim down DMDA a good amount. > > > > > > My vote would be to layer PetscSection on top of DMDA. That would allow > arbitrarily complex data layout over a dead simple > > > topology. Its halfway to DMMesh, and it should be the easy half. > > > > It won't give the proper layout of degree's of freedom relative to their > neighbors of the stagger mesh nor communicate the right ghost points. > > > > Why not? I have done it before. The trial implementation (in C++) is in > src/dm/impls/cartesian. I will just reimplement that completely > > in C. > > If so, why not dump DMDA also and replace it with a dead simple > implementation based on PetscSections? I want to do that, eventually. DMDA is incredibly well tested, and optimized. Matt > > Barry > > > > > Matt > > > > > > Barry > > > > > > > > Matt > > > > > > > > > Barry > > > > > > > > > > > > > > > > > > -- > > > What most experimenters take for granted before they begin their > experiments is infinitely more interesting than any results to which their > experiments lead. > > > -- Norbert Wiener > > > > > > > > > > -- > > What most experimenters take for granted before they begin their > experiments is infinitely more interesting than any results to which their > experiments lead. > > -- Norbert Wiener > > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20110615/fd965024/attachment.html>
