Imported existing code

libraries/include/boost/graph/circle_layout.hpp

@@ -0,0 +1,55 @@
+// Copyright 2004 The Trustees of Indiana University.
+
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+//  Authors: Douglas Gregor
+//           Andrew Lumsdaine
+#ifndef BOOST_GRAPH_CIRCLE_LAYOUT_HPP
+#define BOOST_GRAPH_CIRCLE_LAYOUT_HPP
+#include <boost/config/no_tr1/cmath.hpp>
+#include <utility>
+#include <boost/graph/graph_traits.hpp>
+
+namespace boost {
+  /** 
+   * \brief Layout the graph with the vertices at the points of a regular
+   * n-polygon. 
+   *
+   * The distance from the center of the polygon to each point is
+   * determined by the @p radius parameter. The @p position parameter
+   * must be an Lvalue Property Map whose value type is a class type
+   * containing @c x and @c y members that will be set to the @c x and
+   * @c y coordinates.
+   */
+  template<typename VertexListGraph, typename PositionMap, typename Radius>
+  void 
+  circle_graph_layout(const VertexListGraph& g, PositionMap position,
+                      Radius radius)
+  {
+    const double pi = 3.14159;
+
+#ifndef BOOST_NO_STDC_NAMESPACE
+    using std::sin;
+    using std::cos;
+#endif // BOOST_NO_STDC_NAMESPACE
+
+    typedef typename graph_traits<VertexListGraph>::vertices_size_type 
+      vertices_size_type;
+
+    vertices_size_type n = num_vertices(g);
+    
+    typedef typename graph_traits<VertexListGraph>::vertex_iterator 
+      vertex_iterator;
+
+    vertices_size_type i = 0;
+    for(std::pair<vertex_iterator, vertex_iterator> v = vertices(g); 
+        v.first != v.second; ++v.first, ++i) {
+      position[*v.first].x = radius * cos(i * 2 * pi / n);
+      position[*v.first].y = radius * sin(i * 2 * pi / n);
+    }
+  }
+} // end namespace boost
+
+#endif // BOOST_GRAPH_CIRCLE_LAYOUT_HPP