Dear Prof. Bangerth, MPI_Reduce computes exactly what I want. I checked the values and they are correct. The value higher than 1e10 is probably a MPI bug while trying to find the maximum value. But this problem has nothing to do with my max_rank problem.
I thought maybe you are MPI experts and could give me a hint. For instance this MPI_MAXLOC idea was a great suggestion from Daniel. I also wonder why you haven't included it in deal.II yet. Debugging MPI problems is quite cumbersome, you know that yourself. Setting up such a debugger environment is described in one of your video tutorials, but it takes more time I assume than solving this small problem. I agree, if I want to dive deeply into software design I should improve my MPI skills, but I am merely trying to use tools you offer me in deal.II. As an inventor of deal.II, I think it should be in your interest to help your users find a way solving their problems in your software. Until now, I haven't yet felt the benefits of deal.II since the programming effort is so high it doesn't make up for the computational speed you would gain, "if" you are able to achieve your goals. Hence, telling your interested PhD student to go and "learn debugging" is a bit disappointing. Kind regards, Seyed Ali -- 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 [email protected]. For more options, visit https://groups.google.com/d/optout.
