boost-users-request@lists.boost.org wrote:

Hello,

I want to find the (weakly) connected components and the biconnected components of a directed(bidirectional) graph. But these methods need a undirected graph as input. Does anyone know a simple way to create a undirected graph from a directed graph or a undirected view of a directed graph?

Thanks a lot,

Jean-Noël

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Hi, Probably this could help #include <boost/graph/copy.hpp> boost::copy_graph() if not something like this should work template <class TGraph1, class TGraph2> void directed2undirected(const TGraph1& directed_graph, TGraph2& undirected_graph) { typedef typename boost::graph_traits<TGraph1>::vertex_descriptor vertex1; typedef typename boost::graph_traits<TGraph2>::vertex_descriptor vertex2; typedef typename boost::graph_traits<TGraph1>::edge_iterator edge_iterator; std::vector<vertex1> orig_vertices; std::copy(vertices(directedt_graph).first, vertices(directed_graph).second, std::back_inserter(orig_vertices)); std::map<vertex1, vertex2> vertex_map; // undirected = TGraph2(boost::num_vertices(directed_graph)); for (std::size_t i = 0; i < num_vertices(directed_graph); ++i) { vertex_map[orig_vertices[i]] = boost::add_vertex(undirected_graph); ///Also would be good to copy properties, but it isn't necessary as far as I understand } for (edge_iterator e = edges(directed_graph).first; e != edges(directed_graph).second; ++e) { boost::add_edge(vertex_map[source(*e, directed_graph)], vertex_map[target(*e, directed_graph)], /*directed_graph[*e],*/ undirected_graph); } } I don't know if there is some way to do it without copying. If some, please let me know. Regards, --dmitry