[petsc-users] reuse matrix aij structure

[Matthew Knepley]

On Fri, Sep 25, 2015 at 4:16 AM, Feng Xing <snakexf at gmail.com> wrote:

> Hello everyone,
>
> I want to solve many times A*x=b, where the non-zero structure of A (aij)
> is always same, but its values change. I would like to ask if it is
> possible to call assembly_begin/end only one time, then change the values
> of A each time.
>

You need to call assembly when changing values, but it should be fast.

   Matt


> I find it is possible for a vector(Vec) through VecGetArray. It returns a
> pointer. Is there similar way for matrix? Thank you very much.
>
> Regards,
>
> Feng Xing
> Postdoc at Inria
>
>
>


-- 
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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