text: // Boost.Geometry (aka GGL, Generic Geometry Library)
  // QuickBook Example
  
  // Copyright (c) 2011-2012 Barend Gehrels, Amsterdam, the Netherlands.
  
  // Use, modification and distribution is subject to 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)
  
  //[centroid
  //` Shows calculation of a centroid of a polygon
  
  #include <iostream>
  #include <list>
  
  #include <boost/geometry.hpp>
  #include <boost/geometry/geometries/point_xy.hpp>
  #include <boost/geometry/geometries/polygon.hpp>
  /*<-*/ #include "create_svg_two.hpp" /*->*/
  
  int main()
  {
      typedef boost::geometry::model::d2::point_xy<double> point_type;
      typedef boost::geometry::model::polygon<point_type> polygon_type;
  
      polygon_type poly;
      boost::geometry::read_wkt(
          "POLYGON((2 1.3,2.4 1.7,2.8 1.8,3.4 1.2,3.7 1.6,3.4 2,4.1 3,5.3 2.6,5.4 1.2,4.9 0.8,2.9 0.7,2 1.3)"
              "(4.0 2.0, 4.2 1.4, 4.8 1.9, 4.4 2.2, 4.0 2.0))", poly);
  
      point_type p;
      boost::geometry::centroid(poly, p);
  
      std::cout << "centroid: " << boost::geometry::dsv(p) << std::endl;
      /*<-*/ create_svg("centroid.svg", poly, p); /*->*/
      return 0;
  }
  
  //]
  
  //[centroid_output
  /*`
  Output:
  [pre
  centroid: (4.04663, 1.6349)
  [$img/algorithms/centroid.png]
  ]
  Note that the centroid might be located in a hole or outside a polygon, easily.
  */
  //]
  