[petsc-users] Variable Block Row format in PETSc

[Satish Balay]

AIJ matrix format internally supports VBR listed below [called inodes in PETSc]

So I'm not sure what problem you are having.

Satish

On Tue, 14 May 2013, Longxiang Chen wrote:

> VBR like in this link, use 6 arrays to represent a matrix.
> http://docs.oracle.com/cd/E19061-01/hpc.cluster5/817-0086-10/prog-sparse-support.html
> 
> Each row is a vertex in the graph, , and use parmetis to partition the
> graph to minimize the number of cuts between different processors. (reduce
> communication when calculate Matrix-Vector)
> The matrix is calculated from Jacobian and construct the A and b from the
> result of Jacobian (in VBR).
> 
> 
> Best regards,
> Longxiang Chen
> 
> Do something every day that gets you closer to being done.
> --------------------------------------------------------------
> 465 Winston Chung Hall
> Computer Science Engineering
> University of California, Riverside
> 
> 
> 
> On Tue, May 14, 2013 at 2:51 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
> 
> > What kind of VBR matrix? What are you partitioning using parmetis? A mesh?
> > The blocks of the matrix? How do you create the entries in the matrix?
> > On May 14, 2013 4:36 PM, "Longxiang Chen" <suifengls at gmail.com> wrote:
> >
> >> To whom it may concern,
> >>
> >> I use parmetis to partition a mesh for a sparse matrix.
> >> Then I distribute the data to the  appropriate processors according to
> >> the result of partition.
> >>
> >> The sparse matrix is stored in Variable Block Row(VBR) format.
> >> After the distribution, I want to call PETSc KSP solver to solve Ax = b.
> >> I tried to convert VBR to AIJ or CSR format, but the data would be
> >> re-distributed.
> >>
> >> The ideal method is to keep the distribution result from parmetis.
> >> For example, after parmetis, processor 0 has 0, 1, 4, and processor 1
> >> has 2, 3, 5. I wish the PETSc would not change this distribution and
> >> solve Ax = b.
> >>
> >> Are there any approaches to call KSP solver in VBR format from PETSc?
> >> Or any suggestions for solving Ax = b?
> >>
> >> Thanks in advance.
> >>
> >> Regards,
> >> Longxiang Chen
> >>
> >>
>