W dniu czwartek, 18 października 2018 17:59:40 UTC+2 użytkownik Bruno Turcksin napisał: > > Michal, > > Have you tried to use ARPACK to get the smallest eigenvalues? That's what > we are doing in one of our code and it works pretty well. We have a patch > here > <https://github.com/ORNL-CEES/mfmg/blob/master/scripts/0001-Enable-ARPACK-in-regular-mode.patch> > > so that you don't need to provide the inverse of the operator to use > ARPACK. You still need to provide a mass matrix but it's no used. > > Best, > > Bruno >
Thanks a lot! In the meantime, I found that I was probably using the wrong solver to get inverse (the system may be not SPD) using GMRes resulted in a significant speedup. However, I still have strange results, including the smallest eigenvalue being larger than the largest one. I think using ARPACK instead of my own code will solve the problem, thank you. Michał -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
