Aha ! That should do the trick. Thanks a lot. On Tue, Jul 7, 2015 at 4:54 PM, Matthew Knepley <[email protected]> wrote:
> On Tue, Jul 7, 2015 at 3:52 PM, Bikash Kanungo <[email protected]> wrote: > >> Hi Matthew, >> >> I couldn't follow your reply. It seems a bit unrelated to my query. >> > > Your matrix actually looks like M = A + v^T v, where A is sparse and v is > a small collection of vectors. It is better > is you handle it this way than putting a dense row into a traditional > sparse matrix. > > Matt > > >> >> Thanks, >> Bikash >> >> On Tue, Jul 7, 2015 at 4:42 PM, Matthew Knepley <[email protected]> >> wrote: >> >>> On Tue, Jul 7, 2015 at 3:36 PM, Bikash Kanungo <[email protected]> wrote: >>> >>>> Hi Matthew, >>>> >>>> The entries to the last few rows of my matrix has non-local >>>> contributions from a large number of processors. Since the matrix is >>>> symmetric, I need not set the non-local entries in the last few rows as >>>> they are equal to their transpose entries, which on the other hand are >>>> stored as local entries in their respective processors. >>>> >>> >>> This is really a sparse matrix with a low rank update. It is much easier >>> to handle it this way. There are explicit formulae for the inverse >>> in terms of the inverse of the two parts (Sherman-Morrison-Woodbury), >>> and other operations can be similarly simplified. We might not >>> have all the support now, but pressing forward on this front is likely >>> to be much more fruitful. >>> >>> Thanks, >>> >>> Matt >>> >>> >>>> Thanks, >>>> Bikash >>>> >>>> On Tue, Jul 7, 2015 at 4:25 PM, Matthew Knepley <[email protected]> >>>> wrote: >>>> >>>>> On Tue, Jul 7, 2015 at 3:22 PM, Bikash Kanungo <[email protected]> >>>>> wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> Is there a way to ignore the lower (or upper) triangular entries in >>>>>> an MATMPIAIJ matrix when I know my matrix is symmetric? I can see a >>>>>> MAT_SYMMETRIC option in MatSetOption, but I don't think it ignores any >>>>>> lower (or upper) triangular entry. >>>>>> >>>>> >>>>> Why do you want this? >>>>> >>>>> >>>>>> I cannot use MATMPISBAIJ due to MatMatMult incompatibility with >>>>>> MATMPIAIJ. >>>>>> >>>>> >>>>> This is the only way. MatMatMult() is quite complex and there is no >>>>> real advantage to ignoring >>>>> the entries, so we have not implemented it here. >>>>> >>>>> Matt >>>>> >>>>> >>>>>> Thanks, >>>>>> Bikash >>>>>> >>>>>> -- >>>>>> Bikash S. Kanungo >>>>>> PhD Student >>>>>> Computational Materials Physics Group >>>>>> Mechanical Engineering >>>>>> University of Michigan >>>>>> >>>>>> >>>>> >>>>> >>>>> -- >>>>> 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 >>>>> >>>> >>>> >>>> >>>> -- >>>> Bikash S. Kanungo >>>> PhD Student >>>> Computational Materials Physics Group >>>> Mechanical Engineering >>>> University of Michigan >>>> >>>> >>> >>> >>> -- >>> 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 >>> >> >> >> >> -- >> Bikash S. Kanungo >> PhD Student >> Computational Materials Physics Group >> Mechanical Engineering >> University of Michigan >> >> > > > -- > 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 > -- Bikash S. Kanungo PhD Student Computational Materials Physics Group Mechanical Engineering University of Michigan
