!@thi.ng/k-means

!npm downloads

> [!NOTE]
> This is one of 214 standalone projects, maintained as part
> of the @thi.ng/umbrella monorepo
> and anti-framework.
>
> 🚀 Please help me to work full-time on these projects by sponsoring me on
> GitHub. Thank you! ❤️

- About
- Status
- Installation
- Dependencies
- Usage examples
- API
- Authors
- License

About

k-means & k-medians with customizable distance functions and centroid initializations for n-D vectors.

In addition to the main
kmeans()
implementation, the following k-means centroid initialization functions are
provided (can also be used in isolation to extract cluster centroids):

- kmeansPlusPlus()
- meanCut()
- medianCut()

Status

BETA - possibly breaking changes forthcoming

Search or submit any issues for this package

Installation

``bash
yarn add @thi.ng/k-means
`

ESM import:

`ts
import * as kmeans from "@thi.ng/k-means";
`

Browser ESM import:

`html

`

JSDelivr documentation

For Node.js REPL:

`js
const kmeans = await import("@thi.ng/k-means");
`

Package sizes (brotli'd, pre-treeshake): ESM: 1.10 KB

Dependencies

- @thi.ng/api
- @thi.ng/distance
- @thi.ng/errors
- @thi.ng/random
- @thi.ng/vectors

Note: @thi.ng/api is in _most_ cases a type-only import (not used at runtime)

Usage examples

Two projects in this repo's
/examples
directory are using this package:

| Screenshot | Description | Live demo | Source |
|:-----------------------------------------------------------------------------------------------------------------------|:----------------------------------------------------------------------------|:------------------------------------------------------|:-----------------------------------------------------------------------------------|
| | Color palette generation via dominant color extraction from uploaded images | Demo | Source |
| | k-means clustering visualization | Demo | Source |

API

Generated API docs

Example usage: Clustering cities by lat/lon location

`ts tangle:export/readme.ts
import { HAVERSINE_LATLON } from "@thi.ng/distance";
import { kmeans, meansLatLon } from "@thi.ng/k-means";

// data sourced from:
// https://github.com/OpenDataFormats/worldcities/blob/master/src/data/cities.json
const cities = [
{ id: "anchorage", latlon: [61.21806, -149.90028] },
{ id: "berlin", latlon: [52.52437, 13.41053] },
{ id: "boston", latlon: [42.35843, -71.05977] },
{ id: "calgary", latlon: [51.05011, -114.08529] },
{ id: "cape town", latlon: [-33.92584, 18.42322] },
{ id: "detroit", latlon: [42.33143, -83.04575] },
{ id: "harare", latlon: [-17.82772, 31.05337] },
{ id: "london", latlon: [51.50853, -0.12574] },
{ id: "manila", latlon: [14.6042, 120.9822] },
{ id: "nairobi", latlon: [-1.28333, 36.81667] },
{ id: "new york", latlon: [40.71427, -74.00597] },
{ id: "paris", latlon: [48.85341, 2.3488] },
{ id: "philadelphia", latlon: [39.95233, -75.16379] },
{ id: "portland", latlon: [45.52345, -122.67621] },
{ id: "seoul", latlon: [37.566, 126.9784] },
{ id: "shanghai", latlon: [31.22222, 121.45806] },
{ id: "tokyo", latlon: [35.6895, 139.69171] },
{ id: "vancouver", latlon: [49.24966, -123.11934] },
{ id: "vienna", latlon: [48.20849, 16.37208] },
{ id: "windhoek", latlon: [-22.55941, 17.08323] },
];

// cluster based on lat/lon
const clusters = kmeans(
5,
cities.map((x) => x.latlon),
{
// custom centroid calc for geo locations
// https://docs.thi.ng/umbrella/k-means/functions/meansLatLon.html
strategy: meansLatLon,
// custom distance function for geo location (default: DIST_SQ)
dist: HAVERSINE_LATLON,
}
);

// print each cluster
for (let c of clusters) {
console.log(c.items.map((i) => cities[i].id));
}

// [ 'manila', 'seoul', 'shanghai', 'tokyo' ]
// [ 'berlin', 'london', 'paris', 'vienna' ]
// [ 'boston', 'detroit', 'new york', 'philadelphia' ]
// [ 'cape town', 'harare', 'nairobi', 'windhoek' ]
// [ 'anchorage', 'calgary', 'portland', 'vancouver' ]
`

Authors

- Karsten Schmidt

If this project contributes to an academic publication, please cite it as:

`bibtex
@misc{thing-k-means,
title = "@thi.ng/k-means",
author = "Karsten Schmidt",
note = "https://thi.ng/k-means",
year = 2021
}
``

License

© 2021 - 2026 Karsten Schmidt // Apache License 2.0