From 99040048b7ca467ff61b9a0cba4e56df6fc245ed Mon Sep 17 00:00:00 2001 From: Jean-Paul Pelteret Date: Tue, 10 Jul 2018 14:01:51 +0200 Subject: [PATCH] Enhance parallel::distributed::SolutionTransfer documentation Includes a note on how the old solution vector must be configured with access to locally relevant data --- .../deal.II/distributed/solution_transfer.h | 30 +++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/include/deal.II/distributed/solution_transfer.h b/include/deal.II/distributed/solution_transfer.h index e23d5c1413..962bc4e349 100644 --- a/include/deal.II/distributed/solution_transfer.h +++ b/include/deal.II/distributed/solution_transfer.h @@ -87,6 +87,36 @@ namespace parallel * interpolated_solution.update_ghost_values(); * @endcode * + * As the grid is distributed, it is important to note that the old + * solution(s) must be copied to one that also provides access to the + * locally relevant DoF values (these values required for the interpolation + * process): + * @code + * // Create initial indexsets pertaining to the grid before refinement + * IndexSet locally_owned_dofs, locally_relevant_dofs; + * locally_owned_dofs = dof_handler.locally_owned_dofs(); + * DoFTools::extract_locally_relevant_dofs(dof_handler, + * locally_relevant_dofs); + * + * // The solution vector only knows about locally owned DoFs + * TrilinosWrappers::MPI::Vector solution; + * solution.reinit(locally_owned_dofs, + * mpi_communicator); + * ... + * // Transfer solution to vector that provides access to locally relevant + * DoFs TrilinosWrappers::MPI::Vector old_solution; + * old_solution.reinit(locally_owned_dofs, + * locally_relevant_dofs, + * mpi_communicator); + * old_solution = solution; + * ... + * // Refine grid + * // Recreate locally_owned_dofs and locally_relevant_dofs index sets + * ... + * solution.reinit(locally_owned_dofs, mpi_communicator); + * soltrans.refine_interpolate(old_solution, solution); + * @endcode + * *

Use for Serialization

* * This class can be used to serialize and later deserialize a distributed -- 2.39.5