# how to inverse a sparse matrix in Petsc?

Tue Feb 5 11:26:35 CST 2008

Hi, Tim

According to what you said, if the matrix A has been divided into several
nodes in the cluster, you may use your parallel code to inverse A?
My problem is that what is the distribution of the results?
thanks a lot.

Regards,
Yujie

On 2/5/08, Timothy Stitt <tstitt at cscs.ch> wrote:
>
> Yes Yujie, I was able to put together a parallel code to invert a large
> sparse matrix with the help of the PETSc developers. If you need any
> help or maybe a Fortran code template just let me know.
>
> Best,
>
> Tim.
>
> > Hi
> > There was a discussion between Tim Stitt and petsc developers about
> > matrix inversion, and it was really helpful. That was in last Nov. You
> > can check the emails archive
> >
> >
> >
> >
> > */Yujie <recrusader at gmail.com>/* wrote:
> >
> >     what is the difference between sequantial and parallel AIJ matrix?
> >     Assuming there is a matrix A, if
> >     I partitaion this matrix into A1, A2, Ai... An.
> >     A is a parallel AIJ matrix at the whole view, Ai
> >     is a sequential AIJ matrix? I want to operate Ai at each node.
> >     In addition, whether is it possible to get general inverse using
> >     MatMatSolve() if the matrix is not square? Thanks a lot.
> >
> >     Regards,
> >     Yujie
> >
> >
> >     On 2/4/08, *Barry Smith* <bsmith at mcs.anl.gov
> >     <mailto:bsmith at mcs.anl.gov>> wrote:
> >
> >
> >             For sequential AIJ matrices you can fill the B matrix with
> the
> >         identity and then use
> >         MatMatSolve().
> >
> >             Note since the inverse of a sparse matrix is dense the B
> >         matrix is
> >         a SeqDense matrix.
> >
> >             Barry
> >
> >         On Feb 4, 2008, at 12:37 AM, Yujie wrote:
> >
> >         > Hi,
> >         > Now, I want to inverse a sparse matrix. I have browsed the
> >         manual,
> >         > however, I can't find some information. could you give me
> >         >
> >         > thanks a lot.
> >         >
> >         > Regards,
> >         > Yujie
> >         >
> >
> >
> >
> > ------------------------------------------------------------------------
> > Looking for last minute shopping deals? Find them fast with Yahoo!
> > Search.
> > <
> http://us.rd.yahoo.com/evt=51734/*http://tools.search.yahoo.com/newsearch/category.php?category=shopping
> >
>
>
>
> --
> Timothy Stitt
> HPC Applications Analyst
>
> Swiss National Supercomputing Centre (CSCS)
> Galleria 2 - Via Cantonale
> CH-6928 Manno, Switzerland
>
> +41 (0) 91 610 8233
> stitt at cscs.ch
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20080205/ef5eb69c/attachment.htm>