[Boost-users] filtered graph

From: Matthias Linkenheil (M.Linkenheil_at_[hidden])
Date: 2004-12-22 05:35:51

Hello,

i have a problem with the filtered_graph example ( http://www.boost.org/libs/graph/doc/filtered_graph.html
).

I want to hide the edges with edge_capacity greather than zero like in
the filtered_graph
example.
But this example doesn' t work in my algorithm because my graph is
defined a little bit different and I don't know what I have to change!
(The edge_capacity is calculated with edmunds_karp_max_flow)

Perhaps someone could help me.

Here is a part of my algorithm:

...
template <typename EdgeCapacityMap>
struct positive_edge_capacity {
  positive_edge_capacity() { }
  positive_edge_capacity(EdgeCapacityMap capacity) :
m_capacity(capacity) { }
  template <typename Edge>
  bool operator()(const Edge& e) const {
    return 0 < boost::get(m_capacity, e);
  }
  EdgeCapacityMap m_capacity;
};
...

  typedef adjacency_list_traits<vecS, vecS, directedS> Traits;
  typedef property<vertex_index_t, int> VertexProperties;
  typedef property<edge_capacity_t, double,
          property<edge_residual_capacity_t, double,
          property<edge_reverse_t, Traits::edge_descriptor> >
> EdgeProperties;
  typedef adjacency_list<vecS, vecS, directedS, VertexProperties,
EdgeProperties > Graph;

  typedef graph_traits<Graph>::edge_descriptor edge_descriptor; 
  typedef graph_traits<Graph>::vertex_descriptor
vertex_descriptor;
  const int V = x_size*y_size;
  Graph g(V);
  
  property_map<Graph, vertex_index_t>::type vid =
get(vertex_index, g);
  property_map<Graph, edge_capacity_t>::type cap =
get(edge_capacity, g);
  property_map<Graph, edge_reverse_t>::type rev_edge =
get(edge_reverse, g);
  property_map<Graph, edge_residual_capacity_t >::type res_cap =
get(edge_residual_capacity, g);
...
 edmunds_karp_max_flow(g, s, t);
...
  positive_edge_capacity<cap> filter(get(edge_capacity, g));
  filtered_graph<Graph, positive_edge_capacity<cap> > fg(g,
filter);
...


Thanks,
Matthias Linkenheil