[petsc-dev] sacusp preconditioner - limited to seqaijcusp matrices?

[Barry Smith]

On Sep 20, 2011, at 11:54 AM, Brad Aagaard wrote:

> I tried running a PyLith simulation using the sacusp preconditioner rather than ml. If I have the mat_type set to mpiaijcusp, I get an error message that sacusp preconditioner only works with CUSP matrices. I checked sacusp.c and the code checks to make sure the mat_type is seqaijcusp.

   Since the sacusp preconditioner is no MPI parallel it cannot deal with MPI matrices. ML is a truly (MPI) parallel multi-level preconditioner so it is not really interchangable with sacusp.

    You can use block Jacobi preconditioning -pc_type bjacobi -sub_pc_type sacusp   with sacusp on each block.

   Barry

> 
> Is sacusp limited to seqaijcusp or is this a bug and sacusp.c should allow mpiaijcusp matrices as well?
> 
> Note: sacusp allowed a vec_type of mpicusp.
> 
> Thanks,
> Brad