Matt, I use it too. Last time I checked, though, it seemed to be broken in petsc-dev: I could no longer build it using --download-plapack with configure.py. (I think the problem is that no one finished migrating it to the new direct solver interface -- I haven't had time to investigate, though.)
It was working for me in 2.3.3, though. I assume Yujie is using the release version of PETSc? --Richard Matthew Knepley wrote: > On Mon, Sep 22, 2008 at 9:43 PM, Lisandro Dalcin <dalcinl at gmail.com> wrote: >> On Mon, Sep 22, 2008 at 11:03 PM, Yujie <recrusader at gmail.com> wrote: >>> Dear Lisandro: >>> >>> Barry has tried to establish an interface for Plapack. However, there are >>> some bugs in Plapack. Therefore, it doesn't work. >> Sorry, I didn't know about those Plapack issues. > > Neither did I, and seeing as how I use it, this is interesting. Please > please please > report any bugs you find, because I have been using it without problems. > > Matt > >>> I am wondering if CG in >>> Petsc can work with parallel dense matrix. >> Of course it works. In fact, any other KSP should work. As Barry said, >> The KSP methods are INDEPENDENT of the matrix format, try -pc_type >> jacobi as preconditioner. >> >>> When using the same matrix, which >>> one is faster, sequential or parallel? thanks. >> For a fixed-size matrix, you should get really good speedups iterating >> in parallel. Of course, that would be even better if you can generate >> the local rows of the matrix in each processor. If not, communicating >> the matrix row from the 'master' to the 'slaves' could be a real >> bootleneck (large data to compute at the master while slaves waiting, >> large data to scatter from master to slaves), If you cannot avoid >> dense matrices, then you should try hard to compute the local rows at >> the owning processor. >> >> >>> On Mon, Sep 22, 2008 at 6:51 PM, Lisandro Dalcin <dalcinl at gmail.com> >>> wrote: >>>> Well, any iterative solver will actually work, but expect a really >>>> poor scalability :-). I believe (never used dense matrices) that you >>>> could use a direct method (PLAPACK?), but again, be prepared for long >>>> running times if your problem is (even moderately) large. >>>> >>>> On Mon, Sep 22, 2008 at 10:35 PM, Yujie <recrusader at gmail.com> wrote: >>>>> To my knowledge, PETsc doesn't provide parallel dense matrix-based >>>>> solvers, >>>>> such as for CG, GMRES and so on. If it is, how to deal with this >>>>> problem? >>>>> Thanks. >>>>> >>>>> Regards, >>>>> >>>>> Yujie >>>>> >>>> >>>> >>>> -- >>>> Lisandro Dalc?n >>>> --------------- >>>> Centro Internacional de M?todos Computacionales en Ingenier?a (CIMEC) >>>> Instituto de Desarrollo Tecnol?gico para la Industria Qu?mica (INTEC) >>>> Consejo Nacional de Investigaciones Cient?ficas y T?cnicas (CONICET) >>>> PTLC - G?emes 3450, (3000) Santa Fe, Argentina >>>> Tel/Fax: +54-(0)342-451.1594 >>>> >>> >> >> >> -- >> Lisandro Dalc?n >> --------------- >> Centro Internacional de M?todos Computacionales en Ingenier?a (CIMEC) >> Instituto de Desarrollo Tecnol?gico para la Industria Qu?mica (INTEC) >> Consejo Nacional de Investigaciones Cient?ficas y T?cnicas (CONICET) >> PTLC - G?emes 3450, (3000) Santa Fe, Argentina >> Tel/Fax: +54-(0)342-451.1594 >> >> > > >
