<div class="gmail_quote">On Sat, Jul 16, 2011 at 16:06, Barry Smith <span dir="ltr"><<a href="mailto:bsmith@mcs.anl.gov">bsmith@mcs.anl.gov</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Note that our GMRES is implemented only with left preconditioning and preconditioned residual norm but you can use the FGMRES which is implemented only for right preconditioning and the true residual norm for testing.</blockquote>
</div><br><div>Right preconditioning also works with normal GMRES, run with -ksp_norm_type unpreconditioned -ksp_pc_side right (in petsc-dev, -ksp_right_pc in petsc-3.1).</div>