[petsc-users] Petsc for solving a sparse under-determined system

[Matthew Knepley]

On Sun, Jul 22, 2012 at 2:51 PM, Mengda Wu <wumengda at gmail.com> wrote:

> Hi all,
>
>     How should I use Petsc to solve a sparse under-determined system?
> Basically, I need a quick solution to solve
> Ax=b, where is A is a sparse (possibly nonsymmetric) matrix of size m x n,
> where m<n. The solution I need to find is to minimize |x|^2.
>
>     I know SPQR(http://www.cise.ufl.edu/research/sparse/SPQR/) can do
> this. But if Petsc has some functions or
> wrappers, it will be great to stick with Petsc.
>

Have you tried LSQR, SYMMLQ, or CGNE?

   Matt


> Thanks,
> Mengda
>



-- 
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-users/attachments/20120722/cad1aa18/attachment.html>