Hi- I've just recently started to use the BGL and was wondering if someone could provide an example (and/or just let me know where I am going wrong) in trying to execute the brandes_betweenness_centrality algorithm for a weighted graph. Below are the relevant code snippets from my program. I am able to compile and run the code, and have successfully iterated over all elements (vertices, edges, and "interaction_weights" to verify that the data are stored correctly) but the calculated betweenness values are the same whether or not I use the edge weight map, which suggests that they are not being considered in the calculation even when passed as a parameter to the brandes_betweenness_centrality function. What am I missing? Thank you, Emily #include <boost/graph/graph_traits.hpp> // iterator functions #include <boost/graph/adjacency_list.hpp> #include <boost/graph/betweenness_centrality.hpp> #include <map> #include <vector> using namespace std; using namespace boost; struct order_edges { template <typename T> bool operator() (const T& x, const T& y) const { return x.get_property() < y.get_property(); } }; /* ============================================================= Main ============================================================ */ int main(int argc, char **argv) { // Define the Graph typedef property < vertex_centrality_t, double > CentralityMap; typedef adjacency_list<vecS, vecS, bidirectionalS, CentralityMap> Graph; typedef graph_traits<Graph>::vertex_descriptor Vertex; typedef graph_traits<Graph>::edge_descriptor Edge; typedef map<Edge, double, order_edges> edge_weight_map_t; edge_weight_map_t base_map; associative_property_map<edge_weight_map_t> interaction_weight(base_map); Graph g; // instance of the graph // determine vertices based upon input from a file // add edges and assign values to associated interaction weights from a file .... brandes_betweenness_centrality(g, get(vertex_centrality,g), interaction_weight); }