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- // (C) Copyright Andrew Sutton 2007
- //
- // Use, modification and distribution are subject to the
- // Boost Software License, Version 1.0 (See accompanying file
- // LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
- //[scaled_closeness_centrality_example
- #include <iostream>
- #include <iomanip>
- #include <boost/graph/undirected_graph.hpp>
- #include <boost/graph/exterior_property.hpp>
- #include <boost/graph/floyd_warshall_shortest.hpp>
- #include <boost/graph/closeness_centrality.hpp>
- #include "helper.hpp"
- using namespace std;
- using namespace boost;
- // This template struct provides a generic version of a "scaling"
- // closeness measure. Specifically, this implementation divides
- // the number of vertices in the graph by the sum of geodesic
- // distances of each vertex. This measure allows customization
- // of the distance type, result type, and even the underlying
- // divide operation.
- template <typename Graph,
- typename Distance,
- typename Result,
- typename Divide = divides<Result> >
- struct scaled_closeness_measure
- {
- typedef Distance distance_type;
- typedef Result result_type;
- Result operator ()(Distance d, const Graph& g)
- {
- if(d == numeric_values<Distance>::infinity()) {
- return numeric_values<Result>::zero();
- }
- else {
- return div(Result(num_vertices(g)), Result(d));
- }
- }
- Divide div;
- };
- // The Actor type stores the name of each vertex in the graph.
- struct Actor
- {
- std::string name;
- };
- // Declare the graph type and its vertex and edge types.
- typedef undirected_graph<Actor> Graph;
- typedef graph_traits<Graph>::vertex_descriptor Vertex;
- typedef graph_traits<Graph>::edge_descriptor Edge;
- // The name map provides an abstract accessor for the names of
- // each vertex. This is used during graph creation.
- typedef property_map<Graph, string Actor::*>::type NameMap;
- // Declare a matrix type and its corresponding property map that
- // will contain the distances between each pair of vertices.
- typedef exterior_vertex_property<Graph, int> DistanceProperty;
- typedef DistanceProperty::matrix_type DistanceMatrix;
- typedef DistanceProperty::matrix_map_type DistanceMatrixMap;
- // Declare the weight map so that each edge returns the same value.
- typedef constant_property_map<Edge, int> WeightMap;
- // Declare a container and its corresponding property map that
- // will contain the resulting closeness centralities of each
- // vertex in the graph.
- typedef boost::exterior_vertex_property<Graph, float> ClosenessProperty;
- typedef ClosenessProperty::container_type ClosenessContainer;
- typedef ClosenessProperty::map_type ClosenessMap;
- int
- main(int argc, char *argv[])
- {
- // Create the graph and a property map that provides access
- // to the actor names.
- Graph g;
- NameMap nm(get(&Actor::name, g));
- // Read the graph from standard input.
- read_graph(g, nm, cin);
- // Compute the distances between all pairs of vertices using
- // the Floyd-Warshall algorithm. Note that the weight map is
- // created so that every edge has a weight of 1.
- DistanceMatrix distances(num_vertices(g));
- DistanceMatrixMap dm(distances, g);
- WeightMap wm(1);
- floyd_warshall_all_pairs_shortest_paths(g, dm, weight_map(wm));
- // Create the scaled closeness measure.
- scaled_closeness_measure<Graph, int, float> m;
- // Compute the degree centrality for graph
- ClosenessContainer cents(num_vertices(g));
- ClosenessMap cm(cents, g);
- all_closeness_centralities(g, dm, cm, m);
- // Print the scaled closeness centrality of each vertex.
- graph_traits<Graph>::vertex_iterator i, end;
- for(boost::tie(i, end) = vertices(g); i != end; ++i) {
- cout << setw(12) << setiosflags(ios::left)
- << g[*i].name << get(cm, *i) << endl;
- }
- return 0;
- }
- //]
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