[petsc-users] MatCreateSchurComplementPmat to create a Schur complement

[Matthew Knepley]

On Thu, Jan 21, 2021 at 2:52 AM Tang, Qi <tangqi at msu.edu> wrote:

> Hi,
> When I use the MatCreateSchurComplementPmat to create a Schur complement
> for my own usage, I do not understand the logic
> when preuse=MAT_INITIAL_MATRIX. If all the matrixes are not empty, the
> first thing it did is
> 809:     MatDestroy(Spmat);
> So that means I cannot pass in an empty matrix. It works if I first do
> MatCreate a dummy matrix and then pass in. Is that just some inconsistency
> or is there something I misunderstood?
>

Yes, it wants you to pass &Sp with Sp == NULL. Sorry this is not more clear.

  Thanks,

     Matt


> Qi
>


-- 
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.cse.buffalo.edu/~knepley/>
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