Re: how to inverse a sparse matrix in Petsc?

[Yujie <recrusader@xxxxxxxxx>]

Hi, Tim

Thank you for your help. I am really glad to get your help.
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@xxxxxxx> 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.

Waad Subber wrote:
> 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
>
> http://www-unix.mcs.anl.gov/web-mail-archive/lists/petsc-users/2007/11/threads.html
>
> Waad
>
> */Yujie <recrusader@xxxxxxxxx>/* 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@xxxxxxxxxxx
>     <mailto:bsmith@xxxxxxxxxxx>> 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
>         some advice?
>         >
>         > 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@xxxxxxx