1 // Boost.Geometry (aka GGL, Generic Geometry Library)
2 // QuickBook Example
3
4 // Copyright (c) 2011-2012 Barend Gehrels, Amsterdam, the Netherlands.
5
6 // Use, modification and distribution is subject to the Boost Software License,
7 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
8 // http://www.boost.org/LICENSE_1_0.txt)
9
10 //[length_with_strategy
11 //`The following example shows the length measured over a sphere, expressed in kilometers. To do that the radius of the sphere must be specified in the constructor of the strategy.
12
13 #include <iostream>
14 #include <boost/geometry.hpp>
15 #include <boost/geometry/geometries/linestring.hpp>
16
main()17 int main()
18 {
19 using namespace boost::geometry;
20 typedef model::point<float, 2, cs::spherical_equatorial<degree> > P;
21 model::linestring<P> line;
22 line.push_back(P(2, 41));
23 line.push_back(P(2, 48));
24 line.push_back(P(5, 52));
25 double const mean_radius = 6371.0; /*< [@http://en.wikipedia.org/wiki/Earth_radius Wiki] >*/
26 std::cout << "length is "
27 << length(line, strategy::distance::haversine<float>(mean_radius) )
28 << " kilometers " << std::endl;
29
30 return 0;
31 }
32
33 //]
34
35
36 //[length_with_strategy_output
37 /*`
38 Output:
39 [pre
40 length is 1272.03 kilometers
41 ]
42 */
43 //]
44