On 17.08.2012 16:03, Jed Brown wrote: > > Fine, sounds like you are doing divergence cleaning for an > incompatible spatial discretization. Since the change lies within the > null space of the intended continuous operator, you should be okay. > But note that this procedure is fragile and will have different effect > with different Krylov methods and preconditioning sides.
Right. Could you please explain what do you mean by fragile? > > Looks a bit tricky. The number of fgmres iterations then defines > number of the cycles correction will be applied, doesn't it? > > > Yes. If I do this command line only setup: -pc_type composite -pc_composite_type multiplicative -pc_composite_pcs ksp,shell How does petsc know what ShellPCApply routine to take? I guess I have to specify this in the code anyway? -- Regards, Alexander -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120817/acd67b6b/attachment.html>
