[petsc-dev] [petsc-users] How to compute RARt with A and R as distributed (MPI) matrices ?

[Barry Smith]

> On Jun 21, 2017, at 8:00 AM, Franck Houssen <franck.houssen at inria.fr> wrote:
> 
> How to compute RARt with A and R as distributed (MPI) matrices ?
> 
> This works with sequential matrices.
> The doc say "currently only implemented for pairs of AIJ matrices and classes which inherit from AIJ": I supposed that MPIAIJ was someway inheriting from AIJ, seems that it doesn't.

     Yes, when we say AIJ we mean both SeqAIJ and MPIAIJ. The manual page here is wrong, probably because it got copied from MatPtAP page

> 
> Is this kind of matrix product possible with distributed matrices in PETSc ? Or is this a known limitation ?
> Do I go the wrong way to do that (= should use another method) ? If yes, what is the correct one ?
> 
> Franck
> 
> PS: running debian/testing + gcc-6.3 + bitbucket petsc.
> 
> >> mpirun -n 2 matRARt.exe seq
> Mat Object: 1 MPI processes
>   type: seqaij
> row 0: (0, 1.)  (1, 0.) 
> row 1: (0, 0.)  (1, 1.) 
> 
> >> mpirun -n 2 matRARt.exe mpi
> [0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------
> [0]PETSC ERROR: No support for this operation for this object type
> [0]PETSC ERROR: Matrix of type <mpiaij> does not support RARt
> 
> <matRARt.cpp>