[petsc-users] Distributing already assembled stiffness matrix

[Jed Brown]

Easiest is to assemble into a distributed matrix from rank 0.  So
instead of calling MatCreate using PETSC_COMM_SELF, use a parallel
communicator (like PETSC_COMM_WORLD).  It is fine if only rank 0 calls
MatSetValues, but all processes must call MatAssemblyBegin/End.

"Jaganathan, Srikrishna" <srikrishna.jaganathan at fau.de> writes:

> Hello,
>
>
> I have been trying to distribute a already existing stiffness matrix in 
> my FEM code to petsc parallel matrix object , but I am unable to find 
> any documentation regarding it. It was quite straightforward to create a 
> sequential petsc matrix object and everything was working as intended.I 
> have read some of the user comments in the mailing lists regarding 
> similar situation and most of the times the solution suggested is to 
> create stiffness matrix from the the mesh in distributed format. Since 
> its a little difficult in my case to pass the mesh data in the code , is 
> there anyway to distribute already existing stiffness matrix ?
>
> Thanks and Regards
>
> Srikrishna Jaganathan