nearestPoints

Finds the nearest points between geometry a and geometry b.

The returned points can be points along a line segment, not necessarily one of the vertices of the input geometries.

Parameters

Name	Type	Description
a	Geometry | Prepared<Geometry>	First geometry
b	Geometry	Second geometry

Returns

[ Point, Point ]

An array with two point geometries, first is the nearest point from the geometry a second from the geometry b

Throws

• GEOSError on unsupported geometry types (curved)
• GEOSError when either geometry is empty

See also

• distance computes the distance between two geometries
• distanceWithin returns true when two geometries are within a given distance
• prepare improves performance of repeated calls against a single geometry

Examples

nearest points between point and line

const a = point([ 0, 0 ]);
const b = lineString([ [ 0, 1 ], [ 1, 0 ] ]);
const [ a_pt, b_pt ] = nearestPoints(a, b); // [ <POINT (0 0)>, <POINT (0.5 0.5)> ]

const a = point([ 0, 0 ]); const b = lineString([ [ 0, 1 ], [ 1, 0 ] ]); const [ a_pt, b_pt ] = nearestPoints(a, b); // [ <POINT (0 0)>, <POINT (0.5 0.5)> ]

nearest points between two polygons

const a = polygon([ [ [ 0, 0 ], [ 0, 2 ], [ 1, 0 ], [ 0, 0 ] ] ]);
const b = polygon([ [ [ 1, 1 ], [ 2, 1 ], [ 2, 2 ], [ 1, 2 ], [ 1, 1 ] ] ]);
const [ a_pt, b_pt ] = nearestPoints(a, b); // [ <POINT (0.6 0.8)>, <POINT (1 1)> ]

const a = polygon([ [ [ 0, 0 ], [ 0, 2 ], [ 1, 0 ], [ 0, 0 ] ] ]); const b = polygon([ [ [ 1, 1 ], [ 2, 1 ], [ 2, 2 ], [ 1, 2 ], [ 1, 1 ] ] ]); const [ a_pt, b_pt ] = nearestPoints(a, b); // [ <POINT (0.6 0.8)>, <POINT (1 1)> ]

to improve performance of repeated calls against a single geometry

const a = buffer(point([ 0, 0 ]), 10, { quadrantSegments: 1000 });
// `a` is a polygon with many vertices (4000 in this example)
prepare(a);
// preparation of geometry `a` will improve the performance of repeated
// `nearestPoints` calls, but only those where `a` is the first geometry
const r1 = nearestPoints(a, point([ 12, 0 ]));
const r2 = nearestPoints(a, point([ 12, 1 ]));
const r3 = nearestPoints(point([ 12, 2 ]), a); // no benefit from prepared geometry