@turf/convex

What is @turf/convex?

@turf/convex is a module in the Turf.js library that allows you to compute the convex hull of a set of points. A convex hull is the smallest convex polygon that can enclose all the points in a given dataset. This is useful in various geospatial analyses, such as determining the boundary of a set of geographical points.

What are @turf/convex's main functionalities?

Compute Convex Hull

This feature allows you to compute the convex hull of a set of points. The code sample demonstrates how to create a collection of points and then compute the convex hull using the @turf/convex module.

const turf = require('@turf/turf');

const points = turf.featureCollection([
  turf.point([10, 10]),
  turf.point([20, 20]),
  turf.point([30, 30]),
  turf.point([40, 40]),
  turf.point([50, 50])
]);

const convexHull = turf.convex(points);
console.log(convexHull);

Other packages similar to @turf/convex

hull.js

hull.js is a JavaScript library for computing the convex hull of a set of 2D points. It is lightweight and easy to use, but it focuses solely on convex hull calculations, whereas @turf/convex is part of the larger Turf.js library, which offers a wide range of geospatial analysis tools.

concaveman

concaveman is a fast 2D concave hull algorithm. While it focuses on concave hulls, it can also be used to compute convex hulls by setting the concavity parameter to 1. It is faster and more flexible for certain use cases compared to @turf/convex, but it is not as feature-rich in terms of geospatial analysis.

README

@turf/convex

convex

Takes a Feature or a FeatureCollection and returns a convex hull Polygon.

Internally this uses the convex-hull module that implements a monotone chain hull.

Parameters

• feature (Feature | FeatureCollection) input Feature or FeatureCollection

Examples

var points = turf.featureCollection([
  turf.point([10.195312, 43.755225]),
  turf.point([10.404052, 43.8424511]),
  turf.point([10.579833, 43.659924]),
  turf.point([10.360107, 43.516688]),
  turf.point([10.14038, 43.588348]),
  turf.point([10.195312, 43.755225])
]);

var hull = turf.convex(points);

//addToMap
var addToMap = [points, hull]

Returns Feature<Polygon> a convex hull

---

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/convex

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

$ npm install @turf/turf

Changelog

4.6.0

🚀 New Modules

• @turf/clean-coords Removes redundant coordinates from any GeoJSON Geometry. (PR https://github.com/Turfjs/turf/pull/875 - Author @stebogit)
• @turf/interpolate Takes a set of points and estimates their 'property' values on a grid using the Inverse Distance Weighting (IDW) method.. (PR https://github.com/Turfjs/turf/pull/832 - Author @stebogit)
• @turf/clusters-dbscan Takes a set of Points and partition them into clusters according to DBSCAN's data clustering algorithm. (PR https://github.com/Turfjs/turf/pull/812 and https://github.com/Turfjs/turf/pull/851 - Author @DenisCarriere)

  special mention to this incredibly instructive and fun interactive map by @DenisCarriere 😎👏

• @turf/clusters Provides getCluster, clusterEach, and clusterReduce functions. (PR https://github.com/Turfjs/turf/pull/847 - Author @DenisCarriere)
• @turf/boolean-point-on-line Returns true if a point is on a line. Accepts a optional parameter to ignore the start and end vertices of the linestring. (PR https://github.com/Turfjs/turf/pull/858 - Author @rowanwins)
• @turf/boolean-overlap Takes two features and returns true or false whether or not they overlap, i.e. whether any pair of edges on the two polygons intersect. If there are any edge intersections, the polygons overlap. (PR https://github.com/Turfjs/turf/pull/856 and https://github.com/Turfjs/turf/pull/868 - Author @stebogit @tcql)
• @turf/boolean-equal Determine whether two geometries of the same type have identical X,Y coordinate values. (PR https://github.com/Turfjs/turf/pull/869 - Author @stebogit @tcql)

🏅 New Features/Enhancements

• Sets centered param default to true in @turf/point-grid (PR https://github.com/Turfjs/turf/pull/836 - Contributor @stebogit)
• Adds MultiLineString support for @turf/point-on-line (PR https://github.com/Turfjs/turf/pull/838 - Contributor @stebogit)
• Renames @turf/clusters => @turf/clusters-kmeans, plus adds deprecated warning message to @turf/clusters@4.5.2 (See Issue https://github.com/Turfjs/turf/issues/845)
• Changes output type of @turf/clusters-kmeans (See Issue https://github.com/Turfjs/turf/issues/850 - Contributor @DenisCarriere)
• Adds segmentEach and segmentReduce functions to @turf/meta (See Issue https://github.com/Turfjs/turf/issues/850 - Contributor @DenisCarriere)
• Adds tests and linting on JSDoc in TurfJS core from turf-www; see Issue https://github.com/Turfjs/turf/issues/859 (PR https://github.com/Turfjs/turf/issues/857 + https://github.com/Turfjs/turf/issues/864 + https://github.com/Turfjs/turf/issues/870 - Contributor @DenisCarriere @stebogit)
• Introduces null Geometry support across TurfJS modules (See Issue https://github.com/Turfjs/turf/issues/853) (PR https://github.com/Turfjs/turf/issues/866 - Contributor @DenisCarriere)
• Includes feature(Sub)Index in coordEach/coordReduce (@turf/meta) 🎉 (PR https://github.com/Turfjs/turf/issues/872 - Contributor @DenisCarriere)
• Adds bbox and id params plus geometry method to @turf/helpers (PR https://github.com/Turfjs/turf/issues/877 - Contributor @DenisCarriere)

🐛 Bug Fixes

• Applies @turf/truncate to @turf/line-split splitter input to avoid approximation errors. Fixed #852 (PR https://github.com/Turfjs/turf/pull/855)
• Fixes @turf-mask error (See Issue https://github.com/Turfjs/turf/issues/837) (PR https://github.com/Turfjs/turf/pull/865 - Contributor @thiagoxvo)
• Fixes create-new-module script error on LICENSE file creation (See Issue https://github.com/Turfjs/turf/issues/861) (commit df6986e)
• Fixes @turf/isobands error on commonProperties (See Issue https://github.com/Turfjs/turf/issues/831) (commit 1663f07)