I did eventually solve this problem, but I ran into another one. I think I'm close, I just need a little guidance. The problems occur in assembling the system. I've checked the right-hand side vector and it has some odd features. I'm running the "slide" problem, just like step-33 does. I suppose my question is, how should the system assembly routine be changed to accommodate parallelization? All I did was add an if statement to check whether a cell is locally owned before computing on it. Conceptually, what else needs to change?
Happy to post the modified code if it helps. Ellen Price On Wednesday, December 11, 2019 at 3:53:23 PM UTC-6, Ellen M. Price wrote: > > Hi deal.II users and developers, > > I just started with deal.II and am trying out a sample problem similar to > the one I want to solve. I am trying to use step-33 for conservation > equations and migrate parts of step-40 for the MPI capabilities I need. I > seem to be stuck, however, when I am assembling the system. When I read > from the "current_solution" or "old_solution" variables, I just get zeros, > which lead to nan values in the computation. I'm too new to this software > to know exactly where I've gone wrong, but I suspect I'm reading from the > wrong locations or need to distribute the vector differently? As a concrete > example, when I run in a debugger, the following lines > > std::vector<Sacado::Fad::DFad<double>> > independent_local_dof_values(dofs_per_cell); > > for (unsigned int i = 0; i < dofs_per_cell; ++i) > independent_local_dof_values[i] = current_solution(local_dof_indices[i > ]); > > produce a vector of zero values, even though the initial condition is > certainly not all zeros (based on VTK output and the input deck). Any help > is appreciated; I can post other parts of the program that are modified, > even a diff if that's helpful. > > Ellen Price > -- 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/de17c931-a47b-461b-b684-a4a38493a48b%40googlegroups.com.
