Seyed, after having just a quick glance over your approach there seem to be some more issues you can easily stumble upon: - n_vertices() only gives you the number of vertices for one process, not the global one. In particular, you can't rely on the fact that this is the same for all processes. Furthermore, you (probably) don't initialize all the values of your struct. This might be the reason for the large numbers you are observing. - You seem to rely on a specific numbering of the degrees of freedom in FEValues. In particular, you are assuming that you have only nodal values at the cell vertices. This can only be true for Q1 elements. Furthermore, you rely on the fact that after a local dof for the x-component, a local dof for the y-component is stored. This is an unsafe assumption. The proper way of doing this is to use an appropriate Quadrature object that is initialized with support points at the points you are interested in. Have a look at the FAQ [1,2]. - You seem to first calculate the maximum for each vertex across all the processes and after that the maximum over all vertices. It would probably be easier to first find the maximum value and location on each process and after that just compare this one value across all the processes. This would probably also avoid your problems with large numbers.
Else I can just agree with Wolfgang, learning how to debug is a crucial point if you ever want to build working software. Best, Daniel [1] https://github.com/dealii/dealii/wiki/Frequently-Asked-Questions#how-do-i-access-values-of-discontinuous-elements-at-vertices [2] https://github.com/dealii/dealii/wiki/Frequently-Asked-Questions#how-to-get-the-mapped-position-of-support-points-of-my-element Am Dienstag, 7. März 2017 16:55:47 UTC+1 schrieb Seyed Ali Mohseni: > > Dear all, > > With MPI_Allreduce it works like a charm. Thank you very much everyone. > > Especially Prof. Bangerth and Daniel. > > Kind regards, > S. A. Mohseni > -- 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.
