Thanks for your response, its helpful.
I do have few more questions, most of my matrices are of compressed row
storage format.
1)So when I was creating sequentially , I just used
MatCreateSeqAIJWithArrays , but the same for MPI version is quite
confusing to use. I don't understand how to decide on the local rows(it
would be really helpful if there is an example) .
2)When I also tried using MatSetValues it doesn't seem to use the same
indexing as compressed row storage format.What type of indexing should
be used when MatSetValues are used and called from rank 0 for CRS
Matrices?
On 2017-10-18 13:33, Jed Brown wrote:
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" <[email protected]> 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
