Date: Thu, 15 Apr 2010 13:26:37 -0400 From: jewillco@osl.iu.edu To: boost@lists.boost.org Subject: Re: [boost] CSR graph in max flow
On Thu, 15 Apr 2010, Dan Jiang wrote:
I see several replies from you. But none of them answered my question of how to setup capacity map and reverse_edge map for CSR graph (I got compile error). Did you get that email? If not I can resend it. -Thanks Dan
I sent one with the example for how to get the capacity map -- your bundled edge property didn't have a reverse map. The capacity map is:
boost::property_map<Graph, EdgeProp::*float>::type capacity_map = get(&EdgeProp::capacity, g);
and similar for the other maps.
Ok, I did that, but push_relabel_max_flow errors out at all lines that try to access the capacity or reverse_capacity, e.g.: residual_capacity[*ei] = capacity[*ei];Because both capacity and residual_capacity maps in push_relabel_max_flow are keyed on edge_descriptor while the above definition is key on a "float". How do I fix this if possible? Also, I have another question regarding reverse_edge_map creation from a CSR graph.In case of adjacency list, I can use add_edge to create both forward and backward edges and then add both to reverse_edge map, i.e.,edge_descriptor e1 = add_edge(v1, v2);edge_descriptor e2 = add_edge(v2, v1);rev[e1] = e2;rev[e2] = e1;In case CSR, I am passing an array of std::pair<int, int> to CSR constructor using "unsorted_edges" flag, i.e., I can not get e1 and e2 edge_descriptors as above. So I am thinking of looping through each edge to populate the reverse edge "rev" map: BGL_FORALL_EDGES(e, g, BOOST_Graph) { BOOST_Graph::vertex_descriptor src = boost::source(e, g); BOOST_Graph::vertex_descriptor dst = boost::target(e, g); // Here compiler errors out: term does not evaluate to a function taking 3 arguments std::pair<edge_descriptor, bool> edge = edge(src, dst, g); std::pair<edge_descriptor, bool> edge_rev = edge(dst, src, g); // But compiler errors out here rev[edge.first] = edge_rev.first; }Can you tell me how to fix the compiler errors? Thanks, Dan _________________________________________________________________ Live connected. Get Hotmail & Messenger on your phone. http://go.microsoft.com/?linkid=9724462