randomPolys.js

Generate random polygons efficiently in javascript.

A fast method of generating pseudo-random convex polygons in O(n) time, useful for testing spatial applications.

Considerably faster (albeit "less random") than Pavel Valtr's theorum (see “Probability that n random points are in convex position.”, https://doi.org/10.1007/BF02574070) which runs in O(n log n) time.

I have written and benchmarked both implementations for comparison here: https://jsben.ch/4fgfo.

Installation

Install with NPM or Yarn

npm install randompolys

yarn add randompolys

NPM package info: https://www.npmjs.com/package/randompolys

Yarn package info: https://yarnpkg.com/?q=randompolys

Usage

import RandomPolygon from "randompolys";

const count = 35;
const bounds = {
  topLeft: [50, 50],
  bottomLeft: [250, 250],
}
const epsilon = 3;

const polygon = new RandomPolygon(count, bounds, epsilon);
console.log(polygon.polygon);

Count is the number of points in the polygon

Bounds is an object in the form {topLeft: [x, y], bottomRight: [x, y]} that defines the limits of the polygon. This can be used to set the size and location of the polygons in the available space

Epsilon adjusts the "regularity" of the polygon by narrowing the random distribution of vector lengths by y = x^(1 / epsilon). Default value is 1

Demo

https://bm13563.github.io/randomPolys.js/