distance

Calculate the distance between two geometries.

Description

The free function distance calculates the distance between two geometries. It uses the default strategy, based on the coordinate system of the geometry.

Synopsis

template<typename Geometry1, typename Geometry2>
auto distance(Geometry1 const & geometry1, Geometry2 const & geometry2)

Parameters

Type	Concept	Name	Description
Geometry1 const &	Any type fulfilling a Geometry Concept	geometry1	A model of the specified concept
Geometry2 const &	Any type fulfilling a Geometry Concept	geometry2	A model of the specified concept

Returns

The calculated distance

Header

Either

#include <boost/geometry.hpp>

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

Conformance

The function distance implements function Distance from the OGC Simple Feature Specification.

Supported geometries

	Point	Segment	Box	Linestring	Ring	Polygon	MultiPoint	MultiLinestring	MultiPolygon	Variant
Point
Segment
Box
Linestring
Ring
Polygon
MultiPoint
MultiLinestring
MultiPolygon
Variant

Complexity

For point to geometry: linear

For multi-point to ring/polygon/multi-polygon: currently quadratic

For all other geometry combinations: linearithmic

Example

Shows calculation of distance of point to some other geometries

#include <iostream>
#include <list>

#include <boost/geometry.hpp>
#include <boost/geometry/geometries/linestring.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/polygon.hpp>
#include <boost/geometry/geometries/multi_point.hpp>
#include <boost/geometry/geometries/multi_polygon.hpp>

#include <boost/foreach.hpp>

int main()
{
    typedef boost::geometry::model::d2::point_xy<double> point_type;
    typedef boost::geometry::model::polygon<point_type> polygon_type;
    typedef boost::geometry::model::linestring<point_type> linestring_type;
    typedef boost::geometry::model::multi_point<point_type> multi_point_type;

    point_type p(1,2);
    polygon_type poly;
    linestring_type line;
    multi_point_type mp;

    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);
    line.push_back(point_type(0,0));
    line.push_back(point_type(0,3));
    mp.push_back(point_type(0,0));
    mp.push_back(point_type(3,3));

    std::cout
        << "Point-Poly: " << boost::geometry::distance(p, poly) << std::endl
        << "Point-Line: " << boost::geometry::distance(p, line) << std::endl
        << "Point-MultiPoint: " << boost::geometry::distance(p, mp) << std::endl;

    return 0;
}

Output:

Point-Poly: 1.22066
Point-Line: 1
Point-MultiPoint: 2.23607