Вычисление площади по сферическому избытку / формула Гильера.

Synopsis

template<typename PointOfSegment, typename CalculationType>
class strategy::area::huiller
{
  // ...
};

Template parameter(s)

Constructor(s)

huiller(calculation_type radius = 1.0)

Member Function(s)

void apply(PointOfSegment const & p1, PointOfSegment const & p2, excess_sum & state)

return_type result(excess_sum const & state)

Header

#include <boost/geometry/strategies/spherical/area_huiller.hpp>

Example

Вычислите площадь полигона

#include <iostream>
#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/polygon.hpp>
namespace bg = boost::geometry; 
int main()
{
    // Calculate the area of a cartesian polygon
    bg::model::polygon<bg::model::d2::point_xy<double> > poly;
    bg::read_wkt("POLYGON((0 0,0 7,4 2,2 0,0 0))", poly);
    double area = bg::area(poly);
    std::cout << "Area: " << area << std::endl;
    // Calculate the area of a spherical polygon (for latitude: 0 at equator)
    bg::model::polygon<bg::model::point<float, 2, bg::cs::spherical_equatorial<bg::degree> > > sph_poly;
    bg::read_wkt("POLYGON((0 0,0 45,45 0,0 0))", sph_poly);
    area = bg::area(sph_poly);
    std::cout << "Area: " << area << std::endl;
    return 0;
}

Результат:

Area: 16
Area: 0.339837

See also

area (with strategy)