@turf/envelope

What is @turf/envelope?

@turf/envelope is a module from the Turf.js library that allows you to calculate the bounding box (envelope) of a given GeoJSON feature or set of features. This is useful for determining the minimum bounding rectangle that encloses a set of geographical points, lines, or polygons.

What are @turf/envelope's main functionalities?

Calculate Bounding Box for a Point

This feature allows you to calculate the bounding box for a single point. The code sample creates a point at coordinates [10, 20] and then calculates its bounding box.

const turf = require('@turf/turf');
const point = turf.point([10, 20]);
const envelope = turf.envelope(point);
console.log(envelope);

Calculate Bounding Box for a Polygon

This feature allows you to calculate the bounding box for a polygon. The code sample creates a polygon with specified coordinates and then calculates its bounding box.

const turf = require('@turf/turf');
const polygon = turf.polygon([[
  [10, 20], [30, 40], [50, 60], [10, 20]
]]);
const envelope = turf.envelope(polygon);
console.log(envelope);

Calculate Bounding Box for Multiple Features

This feature allows you to calculate the bounding box for a collection of features. The code sample creates a point and a line, combines them into a feature collection, and then calculates the bounding box for the entire collection.

const turf = require('@turf/turf');
const point = turf.point([10, 20]);
const line = turf.lineString([[30, 40], [50, 60]]);
const featureCollection = turf.featureCollection([point, line]);
const envelope = turf.envelope(featureCollection);
console.log(envelope);

Other packages similar to @turf/envelope

bbox

The 'bbox' package provides similar functionality to @turf/envelope by calculating the bounding box for GeoJSON features. It is a lightweight alternative but may not offer the extensive set of geospatial operations available in the Turf.js library.

geojson-bbox

The 'geojson-bbox' package is another alternative that focuses on calculating the bounding box for GeoJSON objects. It is simple to use and can be a good choice if you only need bounding box calculations without the additional features provided by Turf.js.

README

@turf/envelope

envelope

Takes any number of features and returns a rectangular Polygon that encompasses all vertices.

Parameters

• features (Feature | FeatureCollection) input features

Examples

var fc = {
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "name": "Location A"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [-75.343, 39.984]
      }
    }, {
      "type": "Feature",
      "properties": {
        "name": "Location B"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [-75.833, 39.284]
      }
    }, {
      "type": "Feature",
      "properties": {
        "name": "Location C"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [-75.534, 39.123]
      }
    }
  ]
};

var enveloped = turf.envelope(fc);

var resultFeatures = fc.features.concat(enveloped);
var result = {
  "type": "FeatureCollection",
  "features": resultFeatures
};

//=result

Returns Feature<Polygon> a rectangular Polygon feature that encompasses all vertices

---

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/envelope

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

$ npm install @turf/turf