Jack: FYI, Petsc examples for testing elemental interfaces are petsc-dev/src/mat/examples/tests/ex38.c, ex39.c and ex145.c
petsc-dev/src/ksp/ksp/examples/tests/ex40.c Hong > > On Mon, Jul 23, 2012 at 11:53 AM, Hong Zhang <hzhang at mcs.anl.gov> wrote: > >> Jack: >> >>> >>> I'm getting started on creating documentation right now; it should end >>> up looking very similar to Elemental's. >>> >> >> The detailed instruction will be very helpful, especially >> the sparse matrix data structures. Notify us when the documentation is >> out. >> > > Will do. I just pushed out documentation for the build system: > http://poulson.github.com/Clique/build.html > > The rest should follow soon. > > >> Is this a sparse Cholesky direct solver? >> > > More or less. It currently supports LDL^T and LDL^H factorizations without > pivoting, and the latter certainly works for Hermitian positive-definite > matrices. The current implementation is slightly more general than Cholesky > and should achieve roughly the same performance. > > >> Currently, only mumps supports parallel sparse Cholesky direct solver. >> Yours will be a good addition to the petsc external solvers. >> > > Thanks! I'll do my best to help with the integration when the time comes. > > >> >>> Please keep in mind that there is not _yet_ any support for pivoting, as >>> I needed Clique's functionality for indefinite complex symmetric matrices >>> which are nice enough to be factored accurately without pivoting. >> >> >> Petsc users likely use it as a preconditioner. >> In case of zero pivot, you may provide a routine/option for adding a small >> shift? >> > > Yes, that is what I was thinking. For instance, for Helmholtz equations, > one can get away with very small positive imaginary shifts (the physically > corresponds to slightly damping waves). > > >> >>> Clique's nested dissection is built on top of a nodal graph bisection >>> routine which uses a custom interface to parmetis; I suspect that the graph >>> partitioning is currently the least scalable part of the black-box >>> interface due to KLFM refinement being so hard to parallelize. >> >> >> Xuan has almost finished the petsc-elemental interface >> (see petsc-dev/src/mat/impls/elemental/). >> We would appreciate if you can take a look at it and give us >> your comments/suggests. >> >> > I just took a quick look and will make time to go over it in detail later > today. I'll send out patch if I have any concrete suggestions. > > Jack > > >>> >>> On Mon, Jul 23, 2012 at 10:12 AM, Hong Zhang <hzhang at mcs.anl.gov> wrote: >>> >>>> Xuan will take a look at this. >>>> Hong >>>> >>>> On Mon, Jul 23, 2012 at 9:47 AM, Matthew Knepley <knepley at >>>> gmail.com>wrote: >>>> >>>>> I think we just need a small converter from AIJ: >>>>> >>>>> >>>>> https://bitbucket.org/poulson/clique/src/dc417c7e9403/tests/DistSparseMatrix.cpp >>>>> >>>>> Matt >>>>> >>>>> -- >>>>> 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/20120723/dac5952a/attachment.html>
