<html><body><div style="font-family: times new roman, new york, times, serif; font-size: 12pt; color: #000000"><div>I read the doc, and googled this before to write a dummy example. So, matRARt is only for sequential matrices, and, matPtAP for distributed ones : correct ? (means, I "just" used the "wrong" method)<br></div><div>If so, this is a major difference which does not seem (to me) to be emphasized enough in the doc, in particular for a new user (the matRARt and matPtAP pages are the same with R replaced with Pt). Where was it possible to find this information ?<br></div><div><br></div><div>Franck<br></div><div><br></div><hr id="zwchr"><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;" data-mce-style="border-left: 2px solid #1010FF; margin-left: 5px; padding-left: 5px; color: #000; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><b>De: </b>"Dave May" <dave.mayhem23@gmail.com><br><b>À: </b>"Franck Houssen" <franck.houssen@inria.fr>, "PETSc users list" <petsc-users@mcs.anl.gov>, "petsc-dev" <petsc-dev@mcs.anl.gov><br><b>Envoyé: </b>Mercredi 21 Juin 2017 15:11:27<br><b>Objet: </b>Re: [petsc-users] How to compute RARt with A and R as distributed (MPI) matrices ?<br><div><br></div><div>You can assemble R^t and then use MatPtAP which supports MPIAIJ </div><div><br></div><div><br><div class="gmail_quote"><div>On Wed, 21 Jun 2017 at 15:00, Franck Houssen <<a href="mailto:franck.houssen@inria.fr" target="_blank" data-mce-href="mailto:franck.houssen@inria.fr">franck.houssen@inria.fr</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex" data-mce-style="margin: 0 0 0 .8ex; border-left: 1px #ccc solid; padding-left: 1ex;"><div><div style="font-family:times new roman,new york,times,serif;font-size:12pt;color:#000000" data-mce-style="font-family: times new roman,new york,times,serif; font-size: 12pt; color: #000000;"><div>How to compute RARt with A and R as distributed (MPI) matrices ?</div><div><br></div><div>This works with sequential matrices.</div><div>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.<br></div><div><br></div><div>Is this kind of matrix product possible with distributed matrices in PETSc ? Or is this a known limitation ?</div><div>Do I go the wrong way to do that (= should use another method) ? If yes, what is the correct one ?<br></div><div><br></div><div>Franck<br></div><div><br></div><div>PS: running debian/testing + gcc-6.3 + bitbucket petsc.<br></div><div><br></div><div>>> mpirun -n 2 matRARt.exe seq<br>Mat Object: 1 MPI processes<br> type: seqaij<br>row 0: (0, 1.) (1, 0.) <br>row 1: (0, 0.) (1, 1.) <br><div><br></div></div><div>>> mpirun -n 2 matRARt.exe mpi<br>[0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------<br>[0]PETSC ERROR: No support for this operation for this object type<br>[0]PETSC ERROR: Matrix of type <mpiaij> does not support RARt<br><div><br></div></div></div></div></blockquote></div></div></blockquote><div><br></div></div></body></html>