Am Montag, 18. Februar 2019 22:21:06 UTC+1 schrieb David Wells: > > Hi Gabriel, > > I believe that you are still using the standard deal.II SparseMatrix > class; is this correct? If so, this class won't work with fully distributed > calculations. You will need to use either the Trilinos or PETSc wrappers > since not all information is available on the local processor with the > default SparseMatrix class. > > Either way: I believe the error message you encountered is a result of a > bug in deal.II. I don't think that the routine > GridTools::get_finest_common_cells(), which is called by that particular > make_sparsity_pattern variant, works with distributed triangulations. If > you want to use distributed triangulations you will need to set up the > coupled sparsity pattern in a different way. > > If you want to parallelize step-35, it may be better to start by looking > at step-32, which shows how to implement the Stokes equations (coupled to a > Boussinesq equation) in a fully distributed setting. I believe they set up > the coupling of the matrix with velocity and pressure blocks in a different > way that should work for you. > > Does this make sense? > > Thanks, > David Wells > >> >> Hey, sorry for the late respons, I had some stuff to work at.
Today I had a close look to the Step-32 and 31 tutorial and I think that this doen't help very much because in the Step-32 tutorial the pressure_fe_degree eguals the velocity_fe_degree, which, in my view, makes thi function "make_sparsity_pattern" applicable, because you only have to insert one Dof_Handler object. Thus one can use the same Dof_Handler for velocity and pressure, and everything is created as in the Step-32 In my case the velocity_fe_degree is one degree larger then the pressure_fe_degree. If I understood the construction right, I can't perform it in this case. Do you see my problem, or am I wrong? Best Regards Gabriel -- 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.
