On Thu, Aug 23, 2012 at 2:08 PM, Chris Eldred <chris.eldred at gmail.com>wrote:
> Awesome- that is easy. How do I access that SF? I destroy it inside DMComplexPreallocateOperator(), but we can preserve it. Matt > On Thu, Aug 23, 2012 at 12:54 PM, Matthew Knepley <knepley at gmail.com> > wrote: > > On Thu, Aug 23, 2012 at 1:42 PM, Chris Eldred <chris.eldred at gmail.com> > > wrote: > >> > >> I need the adjacency relations discussed in my other post- the only > >> one that is not part of closure(p) U star(p) is: U > >> cone(support(edge)). Given an edge p, I need all of the edges that > >> cover the same cell as edge p. > > > > > > Okay, then for parallelism, I think you need nothing more than the SF we > get > > from Jacobian preallocation. > > > > Thanks, > > > > Matt > > > >> > >> On Thu, Aug 23, 2012 at 12:17 PM, Matthew Knepley <knepley at gmail.com> > >> wrote: > >> > On Thu, Aug 23, 2012 at 12:26 PM, Chris Eldred < > chris.eldred at gmail.com> > >> > wrote: > >> >> > >> >> Yes- I am implementing the TriSK scheme > >> >> (www.mmm.ucar.edu/people/skamarock/Ringler_et_al_JCP_2009.pdf) on > >> >> arbitrary Voronoi meshes. In order to do wind/flux reconstruction at > >> >> the cell edges, it needs to know about the edges of adjacent cells- > >> >> which are outside of closure(p) U star(p). > >> > > >> > > >> > Great! Stuff that cannot be done with that structured crap. However, > >> > from > >> > quickly looking at > >> > the paper, there is nothing beyond the neighbors, so we can reuse the > >> > code > >> > from > >> > Jacobian preallocation. If you could tell me exactly what adjacency > you > >> > need, we might be > >> > able to do it even more simply. > >> > > >> > Matt > >> > > >> >> > >> >> On Thu, Aug 23, 2012 at 11:16 AM, Jed Brown <jedbrown at mcs.anl.gov> > >> >> wrote: > >> >> > On Thu, Aug 23, 2012 at 12:12 PM, Chris Eldred > >> >> > <chris.eldred at gmail.com> > >> >> > wrote: > >> >> >> > >> >> >> Thanks- that helps a lot. If I need stencils that are larger than > >> >> >> closure(p) U star(p) (for a higher-order finite difference method, > >> >> >> for > >> >> >> example), I assume that I need to create my own PetscSF's that > >> >> >> describe which points need to be ghosted? > >> >> > > >> >> > > >> >> > Is this still a fully unstructured method? The Sieve formalism > >> >> > doesn't > >> >> > give > >> >> > you a very efficient way to do this for structured or > semi-structured > >> >> > grids. > >> >> > > >> >> > Even so, if wider stencils are to be supported, I think it should > be > >> >> > implemented within the library. Doing it outside with the current > >> >> > infrastructure is going to be quite a rabbit hole. > >> >> > > >> >> >> > >> >> >> Is there some documentation or example code that explains the > theory > >> >> >> behind star forests? > >> >> > > >> >> > > >> >> > Docs for the basic operations: > >> >> > > >> >> > http://59A2.org/files/StarForest.pdf > >> >> > >> >> > >> >> > >> >> -- > >> >> Chris Eldred > >> >> DOE Computational Science Graduate Fellow > >> >> Graduate Student, Atmospheric Science, Colorado State University > >> >> B.S. Applied Computational Physics, Carnegie Mellon University, 2009 > >> >> chris.eldred at gmail.com > >> > > >> > > >> > > >> > > >> > -- > >> > 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 > >> > >> > >> > >> -- > >> Chris Eldred > >> DOE Computational Science Graduate Fellow > >> Graduate Student, Atmospheric Science, Colorado State University > >> B.S. Applied Computational Physics, Carnegie Mellon University, 2009 > >> chris.eldred at gmail.com > > > > > > > > > > -- > > 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 > > > > -- > Chris Eldred > DOE Computational Science Graduate Fellow > Graduate Student, Atmospheric Science, Colorado State University > B.S. Applied Computational Physics, Carnegie Mellon University, 2009 > chris.eldred at gmail.com > -- 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/20120823/34099db3/attachment-0001.html>