@turf/centroid

What is @turf/centroid?

@turf/centroid is a module within the Turf.js library that calculates the centroid of a given GeoJSON feature. This is useful for finding the geometric center of various shapes such as polygons, lines, and multi-geometries.

What are @turf/centroid's main functionalities?

Calculate Centroid of a Polygon

This feature calculates the centroid of a polygon. The code sample demonstrates how to create a polygon and then calculate its centroid using the @turf/centroid package.

const turf = require('@turf/centroid');
const polygon = turf.polygon([[
  [-81, 41],
  [-81, 47],
  [-72, 47],
  [-72, 41],
  [-81, 41]
]]);
const centroid = turf.centroid(polygon);
console.log(centroid);

Calculate Centroid of a LineString

This feature calculates the centroid of a LineString. The code sample demonstrates how to create a LineString and then calculate its centroid using the @turf/centroid package.

const turf = require('@turf/centroid');
const line = turf.lineString([
  [-83, 30],
  [-84, 36],
  [-78, 41]
]);
const centroid = turf.centroid(line);
console.log(centroid);

Calculate Centroid of a MultiPolygon

This feature calculates the centroid of a MultiPolygon. The code sample demonstrates how to create a MultiPolygon and then calculate its centroid using the @turf/centroid package.

const turf = require('@turf/centroid');
const multiPolygon = turf.multiPolygon([[
  [[-81, 41], [-81, 47], [-72, 47], [-72, 41], [-81, 41]]
], [
  [[-73, 39], [-73, 45], [-64, 45], [-64, 39], [-73, 39]]
]]);
const centroid = turf.centroid(multiPolygon);
console.log(centroid);

Other packages similar to @turf/centroid

geolib

Geolib is a library for geospatial calculations. It provides functions to calculate distances, areas, and other geometric properties. While it offers centroid calculations, it is more general-purpose compared to @turf/centroid, which is specifically designed for GeoJSON features.

jsts

JSTS (JavaScript Topology Suite) is a library for performing various geometric operations. It includes functions for calculating centroids, but it is more complex and offers a broader range of geometric operations compared to @turf/centroid.

README

@turf/centroid

centroid

Takes one or more features and calculates the centroid using the mean of all vertices. This lessens the effect of small islands and artifacts when calculating the centroid of a set of polygons.

Parameters

• geojson GeoJSON GeoJSON to be centered
• properties [Object] an Object that is used as the Feature's properties

Examples

var polygon = {
  "type": "Feature",
  "properties": {},
  "geometry": {
    "type": "Polygon",
    "coordinates": [[[-81, 41], [-88, 36], [-84, 31], [-80, 33], [-77, 39], [-81, 41]]]
  }
};

var centroid = turf.centroid(polygon);

//addToMap
var addToMap = [polygon, centroid]

Returns Feature<Point> the centroid of the input features

---

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/centroid

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

$ npm install @turf/turf

Changelog

4.4.0

🚀 New Modules

• @turf/line-offset Adds a new lineOffset module as per this issue. Basically takes an input line and returns a new line offset by the distance. (PR https://github.com/Turfjs/turf/pull/729 - Author @rowanwins)
• @turf/polygonize Polygonizes (Multi)LineString(s) into Polygons. Implementation of GEOSPolygonize function (geos::operation::polygonize::Polygonizer). (PR https://github.com/Turfjs/turf/pull/767 - Author @NickCis)
• @turf/transform-rotate Rotates any geojson Feature or Geometry of a specified angle, around its centroid or a given pivot point; all rotations follow the right-hand rule. (Issue https://github.com/Turfjs/turf/issues/747 - Author @stebogit)
• @turf/transform-translate Moves any geojson Feature or Geometry of a specified distance along a Rhumb Line on the provided direction angle. (Issue https://github.com/Turfjs/turf/issues/747 - Author @stebogit)
• @turf/transform-scale Scale a GeoJSON from a given point by a factor of scaling (ex: factor=2 would make the GeoJSON 200% larger). If a FeatureCollection is provided, the origin point will be calculated based on each individual Feature. (Issue https://github.com/Turfjs/turf/issues/747 - Author @stebogit)

🏅 New Features

• Support z-coordinate as input for @turf/turf-tin (PR https://github.com/Turfjs/turf/pull/772)
• Adds properties parameter to @turf/centroid and @turf/center (PR https://github.com/Turfjs/turf/pull/769)
• Include Yarn.lock for all modules & Lerna uses Yarn (Issue https://github.com/Turfjs/turf/issues/704, https://github.com/Turfjs/turf/issues/765, PR https://github.com/Turfjs/turf/pull/766)
• Use Tap at root which enables code coverage reports (Issue https://github.com/Turfjs/turf/issues/328 & PR https://github.com/Turfjs/turf/pull/762)
• Support z-coordinate as input for @turf/pointplane (PR https://github.com/Turfjs/turf/pull/754)
• Add core tests - file management & package.json rules (PR https://github.com/Turfjs/turf/pull/749 & https://github.com/Turfjs/turf/pull/756)

🐛 Bug Fixes

• Website http://turfjs.org is back up and running (Issue https://github.com/Turfjs/turf/issues/777)
• @turf/rhumb-destination issue at 180th meridian (Issue https://github.com/Turfjs/turf/issues/770 & PR https://github.com/Turfjs/turf/pull/771)
• Getting too large numbers for Longitude (Issue https://github.com/Turfjs/turf/issues/758 & PR https://github.com/Turfjs/turf/pull/763)
• Throw error if FeatureCollection not array #751 (PR https://github.com/Turfjs/turf/pull/760)
• Change default param coordinates to 3 @turf/truncate (PR https://github.com/Turfjs/turf/pull/757)
• along returns a point that is not found by @turf/point-on-line (Issue https://github.com/Turfjs/turf/issues/691)
• Fix location of intersect point for @turf/point-on-line. (PR https://github.com/Turfjs/turf/pull/750)
• Handle empty geometries as undefined @turf/buffer (PR https://github.com/Turfjs/turf/pull/746)