[petsc-users] MatCompositeMerge + MatCreateRedundantMatrix

[Matthew Knepley]

On Tue, Feb 19, 2019 at 7:12 PM Marius Buerkle <mbuerkle at web.de> wrote:

> I see. This would work if the matrices are on different subcommumicators ?
> Is it possible to add this functionality ?
>

Hmm, no. That is specialized to serial matrices. You need the inverse of
MatCreateSubMatricesMPI().

  Thanks,

     Matt


> marius
>
>
> You basically need the inverse of MatCreateSubmatrices(). I do not think
> we have that right now, but it could probably be done without too much
> trouble by looking at that code.
>
>   Thanks,
>
>      Matt
>
> On Tue, Feb 19, 2019 at 6:15 AM Marius Buerkle via petsc-users <
> petsc-users at mcs.anl.gov> wrote:
>
>> Hi !
>>
>> Is there some way to combine MatCompositeMerge
>> with MatCreateRedundantMatrix? I basically want to create copies of a
>> matrix from PETSC_COMM_WORLD to subcommunicators, do some work on each
>> subcommunicator and than gather the results back to PETSC_COMM_WORLD,
>> namely  I want to sum the  the invidual matrices from the subcommunicatos
>> component wise and get the resulting matrix on PETSC_COMM_WORLD. Is this
>> somehow possible without going through all the hassle of using MPI
>> directly?
>>
>> marius
>>
>
>
> --
> 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/>
>


-- 
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/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20190219/9fe6dcdc/attachment.html>