Hi Pablo,

On Nov 18, 2014, at 8:41 AM, Pablo Madoery <madoerypablo@gmail.com> wrote:

> Hello, I am having trouble using the push_relabel_max_flow algorithm when i put std::numeric_limits<double>::max() as capacity attribute in some edges.
> is there a maximum value that I can use as capacities. which ?.

I can reproduce this failure with clang on the develop branch.  Can you submit a bug in trac for this issue so it doesn’t get lost?

Thanks.

— Noel Belcourt

>
> This is the example I am using :
>
> #include <iostream>
> #include <boost/graph/adjacency_list.hpp>
> #include <boost/graph/push_relabel_max_flow.hpp>
> #include <boost/graph/graphviz.hpp>
>
> using namespace std;
> using namespace boost;
>
> struct vertexInfo
> {
>
> };
>
> struct edgeInfo
> {
>       double capacity;
>       double residualCapacity;
>       double flow;
>       adjacency_list_traits<vecS, vecS, bidirectionalS>::edge_descriptor rev;
>
>       edgeInfo()
>       {
>               residualCapacity = 1000;
>       }
> };
>
> typedef adjacency_list<vecS, vecS, bidirectionalS, vertexInfo, edgeInfo> Graph;
> typedef Graph::edge_descriptor edge_d;
>
> const char* names[] =
> { "SV", "L1", "L2", "L3", "L4", "ET"};
>
> template<typename Vertex>
> void create_edge(Graph& g, Vertex v0, Vertex v1, double capacity)
> {
>       //the algorithm requires that for each edge u-v in the graph, the edge v-u also exists
>       Graph::edge_descriptor ep0 = (add_edge(v0, v1, g)).first;
>       Graph::edge_descriptor ep1 = (add_edge(v1, v0, g)).first;
>       g[ep0].capacity = capacity;
>       g[ep0].rev = ep1;
>       g[ep1].capacity = 0; // the capacity of v-u needs to be 0
>       g[ep1].rev = ep0;
> }
>
> int main()
> {
>       Graph graph;
>
>       Graph::vertex_descriptor SV = add_vertex(graph);
>       Graph::vertex_descriptor L1 = add_vertex(graph);
>       Graph::vertex_descriptor L2 = add_vertex(graph);
>       Graph::vertex_descriptor L3 = add_vertex(graph);
>       Graph::vertex_descriptor L4 = add_vertex(graph);
>       Graph::vertex_descriptor ET = add_vertex(graph);
>
>
>       create_edge(graph, SV, L1, std::numeric_limits<double>::max());
>       create_edge(graph, SV, L2, std::numeric_limits<double>::max());
>       create_edge(graph, SV, L3, std::numeric_limits<double>::max());
>       create_edge(graph, SV, L4, std::numeric_limits<double>::max());
>
>       create_edge(graph, L3, ET, 1000);
>
>       create_edge(graph, L4, L3, 1000);
>       create_edge(graph, L2, L3, 1000);
>       create_edge(graph, L1, L2, 1000);
>
>       // arcos de vuelta
>       create_edge(graph, L3, L4, 1000);
>       create_edge(graph, L3, L2, 1000);
>       create_edge(graph, L2, L1, 1000);
>
>       std::cout << "Max flow: "
>                       << push_relabel_max_flow(graph, SV, ET, get(&edgeInfo::capacity, graph), get(&edgeInfo::residualCapacity, graph),
>                                       get(&edgeInfo::rev, graph), get(boost::vertex_index, graph)) << std::endl;
>
>       graph_traits<Graph>::vertex_iterator vi, vi_end;
>       graph_traits<Graph>::out_edge_iterator ei, ei_end;
>
>       cout.precision(20);
>       for (tie(vi, vi_end) = vertices(graph); vi!= vi_end; ++vi)
>       {
>               for (tie(ei, ei_end) = out_edges(*vi, graph); ei != ei_end; ++ei)
>               {
>                       graph[*ei].flow = graph[*ei].capacity - graph[*ei].residualCapacity;
>
>                       if (graph[*ei].capacity > 0)
>                       {
>                               std::cout << names[*vi] << " " << names[target(*ei, graph)] << " "
>                                               << (graph[*ei].capacity - graph[*ei].residualCapacity) << "/" << graph[*ei].capacity << std::endl;
>                       }
>               }
>       }
>
>       cout<<"end"<<endl;
>       return 0;
> }
>
>
> -----------------------------------------------------------------------------------------------------------------------------
> And this is the exception:
>
> /home/madoery/boost_1_55_0/boost/graph/push_relabel_max_flow.hpp:706: typename boost::property_traits<CapacityEdgeMap>::value_type boost::push_relabel_max_flow(Graph&, typename boost::graph_traits<Graph>::vertex_descriptor, typename boost::graph_traits<Graph>::vertex_descriptor, CapacityEdgeMap, ResidualCapacityEdgeMap, ReverseEdgeMap, VertexIndexMap) [with Graph = boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, vertexInfo, edgeInfo>, CapacityEdgeMap = boost::adj_list_edge_property_map<boost::bidirectional_tag, double, double&, long unsigned int, edgeInfo, double edgeInfo::*>, ResidualCapacityEdgeMap = boost::adj_list_edge_property_map<boost::bidirectional_tag, double, double&, long unsigned int, edgeInfo, double edgeInfo::*>, ReverseEdgeMap = boost::adj_list_edge_property_map<boost::bidirectional_tag, boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>, boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>&, long unsigned int, edgeInfo, boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int> edgeInfo::*>, VertexIndexMap = boost::vec_adj_list_vertex_id_map<vertexInfo, long unsigned int>, typename boost::property_traits<CapacityEdgeMap>::value_type = double, typename boost::graph_traits<Graph>::vertex_descriptor = long unsigned int]: Assertion `algo.is_flow()' failed.
>
> Thank You

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