assign_values (2 coordinate values)

Assign two coordinates to a geometry (usually a 2D point)

Synopsis

template<typename Geometry, typename Type>
void assign_values(Geometry & geometry, Type const & c1, Type const & c2)

Parameters

Type	Concept	Name	Description
Geometry &	Any type fulfilling a Geometry Concept	geometry	A model of the specified concept
Type const &	numerical type (int, double, ttmath, ...) to specify the coordinates	c1	First coordinate (usually x-coordinate)
Type const &	numerical type (int, double, ttmath, ...) to specify the coordinates	c2	Second coordinate (usually y-coordinate)

Header

Either

#include <boost/geometry.hpp>

#include <boost/geometry/algorithms/assign.hpp>

Example

Shows the usage of assign to set point coordinates, and, besides that, shows how you can initialize ttmath points with high precision

#include <iostream>
#include <iomanip>

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

#if defined(HAVE_TTMATH)
#  include <boost/geometry/extensions/contrib/ttmath_stub.hpp>
#endif


int main()
{
    using boost::geometry::assign_values;


    boost::geometry::model::d2::point_xy<double> p1;
    assign_values(p1, 1.2345, 2.3456);

#if defined(HAVE_TTMATH)
    boost::geometry::model::d2::point_xy<ttmath::Big<1,4> > p2;
    assign_values(p2, "1.2345", "2.3456"); 
#endif

    std::cout
        << std::setprecision(20)
        << boost::geometry::dsv(p1) << std::endl
#if defined(HAVE_TTMATH)
        << boost::geometry::dsv(p2) << std::endl
#endif
        ;

    return 0;
}

It is possible to assign coordinates with other types than the coordinate type. For ttmath, you can e.g. conveniently use strings. The advantage is that it then has higher precision, because if doubles are used for assignments the double-precision is used.

Output:

(1.2344999999999999, 2.3456000000000001)
(1.2345, 2.3456)

Boost C++ Libraries