On Mon, Nov 12, 2018 at 4:31 PM Stogner, Roy H <royst...@ices.utexas.edu> wrote:
> > On Mon, 12 Nov 2018, Yuxiang Wang wrote: > > > Quick question: how do I get the n_nodes for a certain boundary set > (given > > bid)? I know I can do: > > > > MeshBase::const_node_iterator nodeit = > > mesh.bid_nodes_begin(NODE_BOUNDARY_ID); > > const MeshBase::const_node_iterator node_end = > > mesh.bid_nodes_end(NODE_BOUNDARY_ID); > > > > to loop through all the nodes, but would there be a way to find out how > > many nodes are there in the same set? > > Just std::distance, I believe. > This might be a bit slow, depending on what else you are doing. Another possibility would be to call: std::vector<std::tuple<dof_id_type, boundary_id_type>> vec = mesh.get_boundary_info().build_node_list(); which returns a vector of _all_ the (node_id, boundary_id) pairs in the mesh (they will be sorted by node_id). You could then count up the number of entries with a specific boundary_id as needed... -- John _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
