[petsc-users] Determine the positive definiteness

[Matthew Knepley]

On Thu, Jan 10, 2013 at 10:44 AM, w_ang_temp <w_ang_temp at 163.com> wrote:

> Hello,
>
>     I want to determine the positive definiteness. So I want to know
>
> if it is a right way.
>
>     I use "-ksp_type cg -pc_type none". You know, CG does not work for
>
> indefinite matrices. I get "Linear solve did not converge due to
>
> DIVERGED_INDEFINITE_MAT". From the information, I think it is indefinite.
>
> Is it a right way?
>

Its not full proof, but it could be a diagnostic.

  Matt


>     Thanks.
>
>                                             Jim
>
>
>


-- 
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
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