Added boost header

test/external/boost/graph/geodesic_distance.hpp

@@ -0,0 +1,210 @@
+// (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)
+
+#ifndef BOOST_GRAPH_GEODESIC_DISTANCE_HPP
+#define BOOST_GRAPH_GEODESIC_DISTANCE_HPP
+
+#include <boost/graph/detail/geodesic.hpp>
+#include <boost/graph/exterior_property.hpp>
+
+namespace boost
+{
+template <typename Graph,
+          typename DistanceType,
+          typename ResultType,
+          typename Divides = std::divides<ResultType> >
+struct mean_geodesic_measure
+    : public geodesic_measure<Graph, DistanceType, ResultType>
+{
+    typedef geodesic_measure<Graph, DistanceType, ResultType> base_type;
+    typedef typename base_type::distance_type distance_type;
+    typedef typename base_type::result_type result_type;
+
+    result_type operator ()(distance_type d, const Graph& g)
+    {
+        function_requires< VertexListGraphConcept<Graph> >();
+        function_requires< NumericValueConcept<DistanceType> >();
+        function_requires< NumericValueConcept<ResultType> >();
+        function_requires< AdaptableBinaryFunctionConcept<Divides,ResultType,ResultType,ResultType> >();
+
+        return (d == base_type::infinite_distance())
+            ? base_type::infinite_result()
+            : div(result_type(d), result_type(num_vertices(g) - 1));
+    }
+    Divides div;
+};
+
+template <typename Graph, typename DistanceMap>
+inline mean_geodesic_measure<Graph, typename property_traits<DistanceMap>::value_type, double>
+measure_mean_geodesic(const Graph&, DistanceMap)
+{
+    return mean_geodesic_measure<Graph, typename property_traits<DistanceMap>::value_type, double>();
+}
+
+template <typename T, typename Graph, typename DistanceMap>
+inline mean_geodesic_measure<Graph, typename property_traits<DistanceMap>::value_type, T>
+measure_mean_geodesic(const Graph&, DistanceMap)
+{
+    return mean_geodesic_measure<Graph, typename property_traits<DistanceMap>::value_type, T>();
+}
+
+// This is a little different because it's expected that the result type
+// should (must?) be the same as the distance type. There's a type of
+// transitivity in this thinking... If the average of distances has type
+// X then the average of x's should also be type X. Is there a case where this
+// is not true?
+//
+// This type is a little under-genericized... It needs generic parameters
+// for addition and division.
+template <typename Graph, typename DistanceType>
+struct mean_graph_distance_measure
+    : public geodesic_measure<Graph, DistanceType, DistanceType>
+{
+    typedef geodesic_measure<Graph, DistanceType, DistanceType> base_type;
+    typedef typename base_type::distance_type distance_type;
+    typedef typename base_type::result_type result_type;
+
+    inline result_type operator ()(distance_type d, const Graph& g)
+    {
+        function_requires< VertexListGraphConcept<Graph> >();
+        function_requires< NumericValueConcept<DistanceType> >();
+
+        if(d == base_type::infinite_distance()) {
+            return base_type::infinite_result();
+        }
+        else {
+            return d / result_type(num_vertices(g));
+        }
+    }
+};
+
+template <typename Graph, typename DistanceMap>
+inline mean_graph_distance_measure<Graph, typename property_traits<DistanceMap>::value_type>
+measure_graph_mean_geodesic(const Graph&, DistanceMap)
+{
+    typedef typename property_traits<DistanceMap>::value_type T;
+    return mean_graph_distance_measure<Graph, T>();
+}
+
+template <typename Graph,
+          typename DistanceMap,
+          typename Measure,
+          typename Combinator>
+inline typename Measure::result_type
+mean_geodesic(const Graph& g,
+                DistanceMap dist,
+                Measure measure,
+                Combinator combine)
+{
+    function_requires< DistanceMeasureConcept<Measure,Graph> >();
+    typedef typename Measure::distance_type Distance;
+
+    Distance n = detail::combine_distances(g, dist, combine, Distance(0));
+    return measure(n, g);
+}
+
+template <typename Graph,
+            typename DistanceMap,
+            typename Measure>
+inline typename Measure::result_type
+mean_geodesic(const Graph& g, DistanceMap dist, Measure measure)
+{
+    function_requires< DistanceMeasureConcept<Measure,Graph> >();
+    typedef typename Measure::distance_type Distance;
+
+    return mean_geodesic(g, dist, measure, std::plus<Distance>());
+}
+
+template <typename Graph, typename DistanceMap>
+inline double
+mean_geodesic(const Graph& g, DistanceMap dist)
+{ return mean_geodesic(g, dist, measure_mean_geodesic(g, dist)); }
+
+template <typename T, typename Graph, typename DistanceMap>
+inline T
+mean_geodesic(const Graph& g, DistanceMap dist)
+{ return mean_geodesic(g, dist, measure_mean_geodesic<T>(g, dist)); }
+
+
+template <typename Graph,
+            typename DistanceMatrixMap,
+            typename GeodesicMap,
+            typename Measure>
+inline typename property_traits<GeodesicMap>::value_type
+all_mean_geodesics(const Graph& g,
+                    DistanceMatrixMap dist,
+                    GeodesicMap geo,
+                    Measure measure)
+{
+    function_requires< VertexListGraphConcept<Graph> >();
+    typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
+    typedef typename graph_traits<Graph>::vertex_iterator VertexIterator;
+    function_requires< ReadablePropertyMapConcept<DistanceMatrixMap,Vertex> >();
+    typedef typename property_traits<DistanceMatrixMap>::value_type DistanceMap;
+    function_requires< DistanceMeasureConcept<Measure,Graph> >();
+    typedef typename Measure::result_type Result;
+    function_requires< WritablePropertyMapConcept<GeodesicMap,Vertex> >();
+    function_requires< NumericValueConcept<Result> >();
+
+    // NOTE: We could compute the mean geodesic here by performing additional
+    // computations (i.e., adding and dividing). However, I don't really feel
+    // like fully genericizing the entire operation yet so I'm not going to.
+
+    Result inf = numeric_values<Result>::infinity();
+    Result sum = numeric_values<Result>::zero();
+    VertexIterator i, end;
+    for(boost::tie(i, end) = vertices(g); i != end; ++i) {
+        DistanceMap dm = get(dist, *i);
+        Result r = mean_geodesic(g, dm, measure);
+        put(geo, *i, r);
+
+        // compute the sum along with geodesics
+        if(r == inf) {
+            sum = inf;
+        }
+        else if(sum != inf) {
+            sum += r;
+        }
+    }
+
+    // return the average of averages.
+    return sum / Result(num_vertices(g));
+}
+
+template <typename Graph, typename DistanceMatrixMap, typename GeodesicMap>
+inline typename property_traits<GeodesicMap>::value_type
+all_mean_geodesics(const Graph& g, DistanceMatrixMap dist, GeodesicMap geo)
+{
+    function_requires< GraphConcept<Graph> >();
+    typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
+    function_requires< ReadablePropertyMapConcept<DistanceMatrixMap,Vertex> >();
+    typedef typename property_traits<DistanceMatrixMap>::value_type DistanceMap;
+    function_requires< WritablePropertyMapConcept<GeodesicMap,Vertex> >();
+    typedef typename property_traits<GeodesicMap>::value_type Result;
+
+    return all_mean_geodesics(g, dist, geo, measure_mean_geodesic<Result>(g, DistanceMap()));
+}
+
+
+template <typename Graph, typename GeodesicMap, typename Measure>
+inline typename Measure::result_type
+small_world_distance(const Graph& g, GeodesicMap geo, Measure measure)
+{
+    function_requires< DistanceMeasureConcept<Measure,Graph> >();
+    typedef typename Measure::result_type Result;
+
+    Result sum = detail::combine_distances(g, geo, std::plus<Result>(), Result(0));
+    return measure(sum, g);
+}
+
+template <typename Graph, typename GeodesicMap>
+inline typename property_traits<GeodesicMap>::value_type
+small_world_distance(const Graph& g, GeodesicMap geo)
+{ return small_world_distance(g, geo, measure_graph_mean_geodesic(g, geo)); }
+
+}
+
+#endif