@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

• features (Feature | FeatureCollection) input features

Examples

var poly = {
  "type": "Feature",
  "properties": {},
  "geometry": {
    "type": "Polygon",
    "coordinates": [[
      [105.818939,21.004714],
      [105.818939,21.061754],
      [105.890007,21.061754],
      [105.890007,21.004714],
      [105.818939,21.004714]
    ]]
  }
};

var centroidPt = turf.centroid(poly);

var result = {
  "type": "FeatureCollection",
  "features": [poly, centroidPt]
};

//=result

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

4.1.0

New Modules

• @turf/line-arc
• @turf/polygon-to-linestring
• @turf/bbox-clip
• @turf/line-overlap

Enhancements

• added centered param to point-grid (PR: https://github.com/Turfjs/turf/pull/650)
• Single module.export helpers, invariant & meta (Commit: https://github.com/Turfjs/turf/commit/9cebb2100cf545fec49488c80140909ab54358b5)

Bug Fixes

• Turf.invariant fails on string value as coordinate (PR: https://github.com/Turfjs/turf/pull/643)
• Handle precision=0 turf-truncate (PR: https://github.com/Turfjs/turf/pull/641)
• Added radiansToDistance, distanceToRadians & distanceToDegrees to Turf core library from @turf/helpers. (Commit: https://github.com/Turfjs/turf/commit/a88d77a3e7f76860b3c138a716da8b603a407c8e)
• Removed process.hrtime in @turf/polygon-unkink(issue: https://github.com/mclaeysb/simplepolygon/issues/5)