containsProperly

Returns true if geometry b lies in the interior of geometry a.

Geometry a contains geometry b properly if all points of b are in the interior of a.

info

This function needs the geometry a to be prepared.
If geometry a is not prepared this function will prepare it.

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 geometry a contains geometry b properly

Throws

• GEOSError on unsupported geometry types (curved)

See also

• contains more inclusive containsProperly
• covers more inclusive contains
• prepare improves performance of repeated calls against a single geometry

Examples

differences with 'contains'

const a = lineString([ [ 0, 13 ], [ 4, 15 ], [ 2, 10 ] ]);
const b = multiPoint([ [ 2, 10 ], [ 4, 15 ] ]);
const ab_contain = contains(a, b); // true
const ab_containsProperly = containsProperly(a, b); // false - `b` intersect boundary of `a`

const c = polygon([ [ [ 10, 13 ], [ 14, 15 ], [ 15, 10 ], [ 10, 13 ] ] ]);
const d = multiPoint([ [ 12, 14 ], [ 13, 14 ] ]);
const cd_contain = contains(c, d); // true
const cd_containsProperly = containsProperly(c, d); // false - `b` intersect boundary of `a`

const e = polygon([ [ [ 0, 0 ], [ 0, 5 ], [ 5, 5 ], [ 5, 0 ], [ 0, 0 ] ] ]);
const f = lineString([ [ 0, 5 ], [ 5, 5 ], [ 0, 0 ] ]);
const ef_contain = contains(e, f); // true
const ef_containsProperly = containsProperly(e, f); // false - `b` intersect boundary of `a`

const g = polygon([ [ [ 10, 0 ], [ 10, 5 ], [ 15, 5 ], [ 15, 0 ], [ 10, 0 ] ] ]);
const h = polygon([ [ [ 11, 2 ], [ 14, 5 ], [ 15, 1 ], [ 11, 2 ] ] ]);
const gh_contain = contains(g, h); // true
const gh_containsProperly = containsProperly(g, h); // false - `b` intersect boundary of `a`

const a = lineString([ [ 0, 13 ], [ 4, 15 ], [ 2, 10 ] ]); const b = multiPoint([ [ 2, 10 ], [ 4, 15 ] ]); const ab_contain = contains(a, b); // true const ab_containsProperly = containsProperly(a, b); // false - `b` intersect boundary of `a` const c = polygon([ [ [ 10, 13 ], [ 14, 15 ], [ 15, 10 ], [ 10, 13 ] ] ]); const d = multiPoint([ [ 12, 14 ], [ 13, 14 ] ]); const cd_contain = contains(c, d); // true const cd_containsProperly = containsProperly(c, d); // false - `b` intersect boundary of `a` const e = polygon([ [ [ 0, 0 ], [ 0, 5 ], [ 5, 5 ], [ 5, 0 ], [ 0, 0 ] ] ]); const f = lineString([ [ 0, 5 ], [ 5, 5 ], [ 0, 0 ] ]); const ef_contain = contains(e, f); // true const ef_containsProperly = containsProperly(e, f); // false - `b` intersect boundary of `a` const g = polygon([ [ [ 10, 0 ], [ 10, 5 ], [ 15, 5 ], [ 15, 0 ], [ 10, 0 ] ] ]); const h = polygon([ [ [ 11, 2 ], [ 14, 5 ], [ 15, 1 ], [ 11, 2 ] ] ]); const gh_contain = contains(g, h); // true const gh_containsProperly = containsProperly(g, h); // false - `b` intersect boundary of `a`

above example, but adjusted to 'containsProperly'

const a = lineString([ [ 0, 13 ], [ 4, 15 ], [ 2, 10 ] ]);
const b = multiPoint([ [ 3, 12.5 ], [ 4, 15 ] ]);
const ab_containsProperly = containsProperly(a, b); // true

const c = polygon([ [ [ 10, 13 ], [ 14, 15 ], [ 15, 10 ], [ 10, 13 ] ] ]);
const d = multiPoint([ [ 12, 13 ], [ 13, 14 ] ]);
const cd_containsProperly = containsProperly(c, d); // true

const e = polygon([ [ [ 0, 0 ], [ 0, 5 ], [ 5, 5 ], [ 5, 0 ], [ 0, 0 ] ] ]);
const f = lineString([ [ 1, 4 ], [ 4, 4 ], [ 1, 1 ] ]);
const ef_containsProperly = containsProperly(e, f); // true

const g = polygon([ [ [ 10, 0 ], [ 10, 5 ], [ 15, 5 ], [ 15, 0 ], [ 10, 0 ] ] ]);
const h = polygon([ [ [ 11, 2 ], [ 14, 4 ], [ 14, 1 ], [ 11, 2 ] ] ]);
const gh_containsProperly = containsProperly(g, h); // true

const a = lineString([ [ 0, 13 ], [ 4, 15 ], [ 2, 10 ] ]); const b = multiPoint([ [ 3, 12.5 ], [ 4, 15 ] ]); const ab_containsProperly = containsProperly(a, b); // true const c = polygon([ [ [ 10, 13 ], [ 14, 15 ], [ 15, 10 ], [ 10, 13 ] ] ]); const d = multiPoint([ [ 12, 13 ], [ 13, 14 ] ]); const cd_containsProperly = containsProperly(c, d); // true const e = polygon([ [ [ 0, 0 ], [ 0, 5 ], [ 5, 5 ], [ 5, 0 ], [ 0, 0 ] ] ]); const f = lineString([ [ 1, 4 ], [ 4, 4 ], [ 1, 1 ] ]); const ef_containsProperly = containsProperly(e, f); // true const g = polygon([ [ [ 10, 0 ], [ 10, 5 ], [ 15, 5 ], [ 15, 0 ], [ 10, 0 ] ] ]); const h = polygon([ [ [ 11, 2 ], [ 14, 4 ], [ 14, 1 ], [ 11, 2 ] ] ]); const gh_containsProperly = containsProperly(g, h); // true