[petsc-dev] Nullspace with right preconditioning

[Matthew Knepley]

On Wed, Apr 4, 2018 at 3:23 PM, Smith, Barry F. <bsmith at mcs.anl.gov> wrote:

>
>   It may not be broken; it may just be misunderstood or incorrect approach.
>
>   You'll need to explain why and where exactly you think it is broken.


I am solving Stokes. I will push the example for you to run tonight.
Basically, I put in a constant for the pressure
as the nullspace. If you run with gmres/left it gives back a pressure with
integral 0. If you run with gmres/right,
it gives back a pressure with a big integral.

   Matt


>
>   Barry
>
>
>
>
> > On Apr 4, 2018, at 1:13 PM, Matthew Knepley <knepley at gmail.com> wrote:
> >
> > This is broken. Did we know this was broken?
> >
> >   Thanks,
> >
> >      Matt
> >
> > --
> > 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
> >
> > https://www.cse.buffalo.edu/~knepley/
>
>


-- 
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

https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/~mk51/>
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