Hi 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/e2a4f861/attachment.html>