@turf/boolean-contains

What is @turf/boolean-contains?

@turf/boolean-contains is a module from the Turf.js library that provides geospatial analysis tools. This specific module is used to determine if one GeoJSON geometry contains another GeoJSON geometry.

What are @turf/boolean-contains's main functionalities?

Check if a Polygon contains another Polygon

This feature checks if one polygon contains another polygon. In this example, polygon1 contains polygon2, so the result is true.

const turf = require('@turf/turf');
const polygon1 = turf.polygon([[[0, 0], [0, 10], [10, 10], [10, 0], [0, 0]]]);
const polygon2 = turf.polygon([[[2, 2], [2, 8], [8, 8], [8, 2], [2, 2]]]);
const contains = turf.booleanContains(polygon1, polygon2);
console.log(contains); // true

Check if a Polygon contains a Point

This feature checks if a polygon contains a point. In this example, the polygon contains the point, so the result is true.

const turf = require('@turf/turf');
const polygon = turf.polygon([[[0, 0], [0, 10], [10, 10], [10, 0], [0, 0]]]);
const point = turf.point([5, 5]);
const contains = turf.booleanContains(polygon, point);
console.log(contains); // true

Check if a MultiPolygon contains a Polygon

This feature checks if a MultiPolygon contains a polygon. In this example, the MultiPolygon contains the polygon, so the result is true.

const turf = require('@turf/turf');
const multiPolygon = turf.multiPolygon([[[[0, 0], [0, 10], [10, 10], [10, 0], [0, 0]]], [[[20, 20], [20, 30], [30, 30], [30, 20], [20, 20]]]]);
const polygon = turf.polygon([[[2, 2], [2, 8], [8, 8], [8, 2], [2, 2]]]);
const contains = turf.booleanContains(multiPolygon, polygon);
console.log(contains); // true

Other packages similar to @turf/boolean-contains

geolib

Geolib is a library for geospatial calculations. It provides functions to check if a point is inside a polygon, calculate distances, and more. Compared to @turf/boolean-contains, geolib offers a broader range of geospatial functions but may not be as specialized in GeoJSON operations.

jsts

JSTS (JavaScript Topology Suite) is a library for performing operations on geometries. It includes functions for spatial relationships like contains, intersects, and more. JSTS is more comprehensive in terms of geometric operations but can be more complex to use compared to @turf/boolean-contains.

leaflet

Leaflet is a popular library for interactive maps. It includes basic geospatial functions like checking if a point is within a polygon. While Leaflet is primarily focused on map rendering and interaction, it provides some geospatial analysis capabilities similar to @turf/boolean-contains.

README

@turf/boolean-contains

booleanContains

Boolean-contains returns True if the second geometry is completely contained by the first geometry. The interiors of both geometries must intersect and, the interior and boundary of the secondary (geometry b) must not intersect the exterior of the primary (geometry a). Boolean-contains returns the exact opposite result of the @turf/boolean-within.

Parameters

• feature1 (Geometry | Feature<any>) GeoJSON Feature or Geometry
• feature2 (Geometry | Feature<any>) GeoJSON Feature or Geometry

Examples

const point = {
  "type": "Feature",
  "properties": {},
  "geometry": {
    "type": "Point",
    "coordinates": [1, 2]
  }
}
const line = {
  "type": "Feature",
  "properties": {},
  "geometry": {
    "type": "LineString",
    "coordinates": [[1, 1], [1, 2], [1, 3], [1, 4]]
  }
}
turf.booleanContains(line, point);
//=true

Returns Boolean true/false

---

This module is part of the Turfjs project, an open source module collection dedicated to geographic algorithms. It is maintained in the Turfjs/turf repository, where you can create PRs and issues.

Installation

Install this module individually:

$ npm install @turf/boolean-contains

Or install the Turf module that includes it as a function:

$ npm install @turf/turf