[petsc-users] Petsc error: cannot chang local size of Amat after use old sizes 10 10 new sizes 11 11

[Matthew Knepley]

On Sat, May 12, 2018 at 8:08 AM, 我 <dayedut123 at 163.com> wrote:

>
> Thanks for your reply! I'm confused about how to create a new matrix
> during the time step advancing.
> For better understand my problem, simple pseudo code (just contains the
> main functions)  like this:
>

It looks like MatDestroy should come before the next Create.

  Matt


> /////////////////////////////////
> KSP ksp;
> PC pc;
> KSPCreate;
> Mat A;
> for(int timestep=0; timestep<20; timestep++)
> {
> //for example
> if(timestep==2)
> {
> localsize change;
> }
> MatCreateMPIAIJWithArrays(PETSC_COMM_WORLD, localsize, localsize, m, m,
> istore, jstore, vstore, &A);
> KSPSolve;
>
> MatDestroy(&A);
> }
> /////////////////////////////
> Thanks again!
> Daye
>
>
>
>
> At 2018-05-11 19:07:35, "Matthew Knepley" <knepley at gmail.com> wrote:
>
> On Fri, May 11, 2018 at 4:23 AM, 我 <dayedut123 at 163.com> wrote:
>
>> Hello all,
>> I use the function MatCreateMPIAIJWithArrays to construct my matrix. But
>> the number of local rows m and local columns n may change during the
>> timestep advancing.  When the local size changes, the error like "Petsc
>> error: cannot chang local size of Amat after use old sizes 10 10 new sizes
>> 11 11" will appear. Any suggestions about it ?
>>
>
> If the parallel layout changes, you need to create a new matrix.
>
>   Thanks,
>
>     Matt
>
>
>> Thank you very much!
>> Daye
>>
>>
>>
>>
>
>
>
> --
> 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/>
>
>
>
>
>



-- 
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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