Turf

A modular geospatial engine written in JavaScript

README

======

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A modular geospatial engine written in JavaScript

turfjs.org

- - -

Turf is a JavaScript library for spatial analysis. It includes traditional spatial operations, helper functions for creating GeoJSON data, and data classification and statistics tools. Turf can be added to your website as a client-side plugin, or you can run Turf server-side with Node.js (see below).

Installation

In Node.js

``` sh
# get all of turf
npm install @turf/turf
# or get individual packages
npm install @turf/helpers
npm install @turf/buffer
```

In browser

Download the minified file, and include it in a script tag. This will expose a global variable namedturf.

``` html
<script src="turf.min.js" charset="utf-8"></script>
```

You can also include it directly from a CDN:

``` html
<script src="https://cdn.jsdelivr.net/npm/@turf/turf@6/turf.min.js"></script>
```

TypeScript

TypeScript definitions are packaged with each module. No DefinitelyTyped packages required.

Other languages

Ports of Turf.js are available in:

- Java (Android, Java SE)

- > The current to-do list for porting to Java

- Swift (iOS, macOS, tvOS, watchOS, Linux)

- > Turf for Swift is experimental and its public API is subject to change. Please use with care.

- Dart/Flutter (Dart Web, Dart Native; Flutter for iOS, Android, macOS, Windows, Linux, Web)

- > The Turf for Dart port is still in progress, the implementation status can be found in the README.

- - -

Data in Turf

Turf uses GeoJSON for all geographic data. Turf expects the data to be standard WGS84 longitude, latitude coordinates. Check out geojson.io for a tool to easily create this data.

NOTE: Turf expects data in (longitude, latitude) order per the GeoJSON standard.

Most Turf functions work with GeoJSON features. These are pieces of data that represent a collection of properties (ie: population, elevation, zipcode, etc.) along with a geometry. GeoJSON has several geometry types such as:

Point

LineString

Polygon

Turf provides a few geometry functions of its own. These are nothing more than simple (and optional) wrappers that output plain old GeoJSON. For example, these two methods of creating a point are functionally equivalent:

``` js
// Note order: longitude, latitude.
var point1 = turf.point([-73.988214, 40.749128]);
var point2 = {
type: 'Feature',
geometry: {
type: 'Point',
// Note order: longitude, latitude.
coordinates: [-73.988214, 40.749128]
},
properties: {}
};
```

Browser support

Turf packages are compiled to target ES2017. However, the browser version of @turf/turf is transpiled to also include support for IE11. If you are using these packages and need to target IE11, please transpile the following packages as part of your build:

```
@turf/*
robust-predicates
rbush
tinyqueue
```

Contributors

This project exists thanks to all the people who contribute. If you are interested in helping, check out the Contributing Guide.

Backers

Thank you to all our backers! 🙏 [Become a backer]