[petsc-users] MatConvert changes distribution of local rows

[Pierre Jolivet]

> On 13 Jan 2023, at 9:18 AM, Marius Buerkle <mbuerkle at web.de> wrote:
> 
> Matrix types is from MATMPIDENSE to MATSCALAPACK,

OK, that’s not possible, because PETSc and ScaLAPACK use different distributions for dense matrices.

> but I think it happens also for other matrix types IIRC.

Which one?

Thanks,
Pierre

>   
> Gesendet: Freitag, 13. Januar 2023 um 16:58 Uhr
> Von: "Pierre Jolivet" <pierre at joliv.et>
> An: "Marius Buerkle" <mbuerkle at web.de>
> Cc: petsc-users at mcs.anl.gov
> Betreff: Re: [petsc-users] MatConvert changes distribution of local rows
>  
> On 13 Jan 2023, at 8:49 AM, Marius Buerkle <mbuerkle at web.de> wrote:
>  
> Hi,
>  
> I have a matrix A for which I defined the number of local rows per process manually using MatSetSizes. When I use MatConvert to change the matrix type it changes the number of local rows (to what one would get if MatSetSize is called with PETSC_DECIDE for number of local rows), which causes problems when doing MatVec producs and stuff like that. Is there any way to preserve the the number of local rows when using MatConvert?
>  
> This is most likely a bug, it’s not handled properly in some MatConvert() implementations.
> Could you please share either the matrix types or a minimal working example?
>  
> Thanks,
> Pierre
>  
>  
> Best,
> Marius

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20230113/daeed686/attachment.html>