A modular geospatial engine written in JavaScript
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:
npm install turfIn browser:
Download the minified file, and include it in a script tag. This will expose a global variable named "turf".
<script src="turf.min.js" charset="utf-8"></script>Browserify:
All of Turf's functions can also be installed as seperate modules. This works well with tools like browserify where you only want to install only the code you need. It also allows you to mix and match modules as needed. This is the recommended usage pattern for most production environments. For example, to install the point and buffer modules use:
npm install turf-point
npm install turf-buffer###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.
Most Turf functions work with GeoJSON features. These are 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:
var point1 = turf.point(0,0);
var point2 = {
type: 'Feature',
geometry: {
type: 'Point',
coordinates: [0, 0]
},
properties: {}
};
##Functions
####geometry
####joins
####data
####measurement
####interpolation
####classification
####aggregation
####transformation
####misc
