@turf/intersect

What is @turf/intersect?

@turf/intersect is a module of the Turf.js library that provides geospatial analysis tools. Specifically, it allows users to compute the intersection of two or more geometries, such as polygons or lines. This is useful in various applications like geographic information systems (GIS), urban planning, and environmental modeling.

What are @turf/intersect's main functionalities?

Polygon Intersection

This feature allows you to find the intersection of two polygons. The code sample demonstrates how to create two polygons and compute their intersection.

const turf = require('@turf/turf');
const polygon1 = turf.polygon([[[0, 0], [2, 0], [2, 2], [0, 2], [0, 0]]]);
const polygon2 = turf.polygon([[[1, 1], [3, 1], [3, 3], [1, 3], [1, 1]]]);
const intersection = turf.intersect(polygon1, polygon2);
console.log(intersection);

Line Intersection

This feature allows you to find the intersection of two lines. The code sample demonstrates how to create two lines and compute their intersection.

const turf = require('@turf/turf');
const line1 = turf.lineString([[0, 0], [2, 2]]);
const line2 = turf.lineString([[0, 2], [2, 0]]);
const intersection = turf.intersect(line1, line2);
console.log(intersection);

MultiPolygon Intersection

This feature allows you to find the intersection of two multipolygons. The code sample demonstrates how to create two multipolygons and compute their intersection.

const turf = require('@turf/turf');
const multiPolygon1 = turf.multiPolygon([[[[0, 0], [2, 0], [2, 2], [0, 2], [0, 0]]]]);
const multiPolygon2 = turf.multiPolygon([[[[1, 1], [3, 1], [3, 3], [1, 3], [1, 1]]]]);
const intersection = turf.intersect(multiPolygon1, multiPolygon2);
console.log(intersection);

Other packages similar to @turf/intersect

jsts

JSTS (JavaScript Topology Suite) is a JavaScript library for performing various geometric operations, including intersections. It is similar to @turf/intersect but offers a broader range of geometric functions and is based on the Java Topology Suite (JTS).

martinez-polygon-clipping

Martinez Polygon Clipping is a library for performing boolean operations on polygons, such as intersection, union, and difference. It is highly efficient and specifically designed for polygon operations, making it a good alternative to @turf/intersect for polygon-specific tasks.

rbush

RBush is a high-performance JavaScript library for 2D spatial indexing of points and rectangles. While it does not directly perform intersections, it can be used in conjunction with other libraries to efficiently manage and query spatial data, which can then be used for intersection operations.

README

@turf/intersect

intersect

Takes two polygons and finds their intersection. If they share a border, returns the border; if they don't intersect, returns undefined.

Parameters

• poly1 Feature<Polygon> the first polygon
• poly2 Feature<Polygon> the second polygon

Examples

var poly1 = {
  "type": "Feature",
  "properties": {
    "fill": "#0f0"
  },
  "geometry": {
    "type": "Polygon",
    "coordinates": [[
      [-122.801742, 45.48565],
      [-122.801742, 45.60491],
      [-122.584762, 45.60491],
      [-122.584762, 45.48565],
      [-122.801742, 45.48565]
    ]]
  }
}
var poly2 = {
  "type": "Feature",
  "properties": {
    "fill": "#00f"
  },
  "geometry": {
    "type": "Polygon",
    "coordinates": [[
      [-122.520217, 45.535693],
      [-122.64038, 45.553967],
      [-122.720031, 45.526554],
      [-122.669906, 45.507309],
      [-122.723464, 45.446643],
      [-122.532577, 45.408574],
      [-122.487258, 45.477466],
      [-122.520217, 45.535693]
    ]]
  }
}

var polygons = {
  "type": "FeatureCollection",
  "features": [poly1, poly2]
};

var intersection = turf.intersect(poly1, poly2);

//=polygons

//=intersection

Returns (Feature<Polygon> | undefined | Feature<MultiLineString>) if poly1 and poly2 overlap, returns a Polygon feature representing the area they overlap; if poly1 and poly2 do not overlap, returns undefined; if poly1 and poly2 share a border, a MultiLineString of the locations where their borders are shared

---

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/intersect

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

$ npm install @turf/turf