get

Get coordinate value of a geometry (usually a point)

The free functions get and set are two of the most important functions of Boost.Geometry, both within the library, as also for the library user. With these two functions you normally get and set coordinate values from and for a point, box, segment or sphere.

Synopsis

template<std::size_t Dimension, typename Geometry>
coordinate_type<Geometry>::type get(Geometry const & geometry)

Parameters

Type	Concept	Name	Description
Dimension	Dimension, this template parameter is required. Should contain [0 .. n-1] for an n-dimensional geometry	-	Must be specified
Geometry const &	Any type fulfilling a Geometry Concept (usually a Point Concept)	geometry	A model of the specified concept (usually a point)

Returns

The coordinate value of specified dimension of specified geometry

Header

Either

#include <boost/geometry.hpp>

#include <boost/geometry/core/access.hpp>

Behavior

Case	Behavior
Point	Returns the coordinate of a point
Circle or Sphere	Returns the coordinate of the center of a circle or sphere (currently in an extension)
Spherical	Returns the coordinate of a point, in either Radian's or Degree's, depending on specified units

Complexity

Constant

Example

Get the coordinate of a point

#include <iostream>

#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point_xy.hpp>

namespace bg = boost::geometry;

int main()
{
    bg::model::d2::point_xy<double> point(1, 2);

    double x = bg::get<0>(point);
    double y = bg::get<1>(point);

    std::cout << "x=" << x << " y=" << y << std::endl;

    return 0;
}

Output:

x=1 y=2