touches

Returns true if the only points in common between geometry a and b are on their boundaries.

warning

Do not use this function with invalid geometries. You will get unexpected results.

Parameters

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

Returns

boolean

true if a intersect with b, but their interiors do not intersect

Throws

• GEOSError on unsupported geometry types (curved)

See also

• prepare improves performance of repeated calls against a single geometry

Examples

touches: true

const a = lineString([ [ 0, 10 ], [ 2, 14 ], [ 5, 15 ] ]);
const b = point([ 0, 10 ]);
const ab_touch = touches(a, b); // true

const c = lineString([ [ 10, 10 ], [ 12, 14 ], [ 15, 15 ] ]);
const d = lineString([ [ 13, 10 ], [ 11, 12 ] ]);
const cd_touch = touches(c, d); // true

const e = lineString([ [ 20, 10 ], [ 22, 14 ], [ 25, 15 ] ]);
const f = polygon([ [ [ 22, 10 ], [ 21, 12 ], [ 25, 13 ], [ 25, 10 ], [ 22, 10 ] ] ]);
const ef_touch = touches(e, f); // true

const g = polygon([ [ [ 2, 0 ], [ 1, 2 ], [ 5, 3 ], [ 5, 0 ], [ 2, 0 ] ] ]);
const h = point([ 1, 2 ]);
const gh_touch = touches(g, h); // true

const i = polygon([ [ [ 12, 0 ], [ 11, 2 ], [ 15, 3 ], [ 15, 0 ], [ 12, 0 ] ] ]);
const j = polygon([ [ [ 11, 3 ], [ 12, 5 ], [ 15, 3 ], [ 11, 3 ] ] ]);
const ij_touch = touches(i, j); // true

const k = polygon([ [ [ 22, 0 ], [ 21, 2 ], [ 25, 3 ], [ 25, 0 ], [ 22, 0 ] ] ]);
const l = polygon([ [ [ 21, 2 ], [ 22, 5 ], [ 25, 3 ], [ 21, 2 ] ] ]);
const kl_touch = touches(k, l); // true

const a = lineString([ [ 0, 10 ], [ 2, 14 ], [ 5, 15 ] ]); const b = point([ 0, 10 ]); const ab_touch = touches(a, b); // true const c = lineString([ [ 10, 10 ], [ 12, 14 ], [ 15, 15 ] ]); const d = lineString([ [ 13, 10 ], [ 11, 12 ] ]); const cd_touch = touches(c, d); // true const e = lineString([ [ 20, 10 ], [ 22, 14 ], [ 25, 15 ] ]); const f = polygon([ [ [ 22, 10 ], [ 21, 12 ], [ 25, 13 ], [ 25, 10 ], [ 22, 10 ] ] ]); const ef_touch = touches(e, f); // true const g = polygon([ [ [ 2, 0 ], [ 1, 2 ], [ 5, 3 ], [ 5, 0 ], [ 2, 0 ] ] ]); const h = point([ 1, 2 ]); const gh_touch = touches(g, h); // true const i = polygon([ [ [ 12, 0 ], [ 11, 2 ], [ 15, 3 ], [ 15, 0 ], [ 12, 0 ] ] ]); const j = polygon([ [ [ 11, 3 ], [ 12, 5 ], [ 15, 3 ], [ 11, 3 ] ] ]); const ij_touch = touches(i, j); // true const k = polygon([ [ [ 22, 0 ], [ 21, 2 ], [ 25, 3 ], [ 25, 0 ], [ 22, 0 ] ] ]); const l = polygon([ [ [ 21, 2 ], [ 22, 5 ], [ 25, 3 ], [ 21, 2 ] ] ]); const kl_touch = touches(k, l); // true

touches: false

const a = lineString([ [ 0, 10 ], [ 2, 14 ], [ 5, 15 ] ]);
const b = point([ 1, 12 ]);
const ab_touch = touches(a, b); // false

const c = lineString([ [ 10, 10 ], [ 12, 14 ], [ 15, 15 ] ]);
const d = lineString([ [ 9, 13 ], [ 15, 15 ] ]);
const cd_touch = touches(c, d); // false

const e = lineString([ [ 22, 11 ], [ 22, 14 ], [ 25, 15 ] ]);
const f = polygon([ [ [ 22, 10 ], [ 21, 12 ], [ 25, 13 ], [ 25, 10 ], [ 22, 10 ] ] ]);
const ef_touch = touches(e, f); // false

const g = polygon([ [ [ 2, 0 ], [ 1, 2 ], [ 5, 3 ], [ 5, 0 ], [ 2, 0 ] ] ]);
const h = point([ 3, 1 ]);
const gh_touch = touches(g, h); // false

const i = polygon([ [ [ 12, 0 ], [ 11, 2 ], [ 15, 3 ], [ 15, 0 ], [ 12, 0 ] ] ]);
const j = polygon([ [ [ 11, 3 ], [ 12, 5 ], [ 14, 2 ], [ 11, 3 ] ] ]);
const ij_touch = touches(i, j); // false

const k = polygon([ [ [ 22, 0 ], [ 21, 2 ], [ 25, 3 ], [ 25, 0 ], [ 22, 0 ] ] ]);
const l = polygon([ [ [ 21, 2 ], [ 23, 1 ], [ 25, 3 ], [ 21, 2 ] ] ]);
const kl_touch = touches(k, l); // false

const a = lineString([ [ 0, 10 ], [ 2, 14 ], [ 5, 15 ] ]); const b = point([ 1, 12 ]); const ab_touch = touches(a, b); // false const c = lineString([ [ 10, 10 ], [ 12, 14 ], [ 15, 15 ] ]); const d = lineString([ [ 9, 13 ], [ 15, 15 ] ]); const cd_touch = touches(c, d); // false const e = lineString([ [ 22, 11 ], [ 22, 14 ], [ 25, 15 ] ]); const f = polygon([ [ [ 22, 10 ], [ 21, 12 ], [ 25, 13 ], [ 25, 10 ], [ 22, 10 ] ] ]); const ef_touch = touches(e, f); // false const g = polygon([ [ [ 2, 0 ], [ 1, 2 ], [ 5, 3 ], [ 5, 0 ], [ 2, 0 ] ] ]); const h = point([ 3, 1 ]); const gh_touch = touches(g, h); // false const i = polygon([ [ [ 12, 0 ], [ 11, 2 ], [ 15, 3 ], [ 15, 0 ], [ 12, 0 ] ] ]); const j = polygon([ [ [ 11, 3 ], [ 12, 5 ], [ 14, 2 ], [ 11, 3 ] ] ]); const ij_touch = touches(i, j); // false const k = polygon([ [ [ 22, 0 ], [ 21, 2 ], [ 25, 3 ], [ 25, 0 ], [ 22, 0 ] ] ]); const l = polygon([ [ [ 21, 2 ], [ 23, 1 ], [ 25, 3 ], [ 21, 2 ] ] ]); const kl_touch = touches(k, l); // false