# median-quickselect

> Fast implementation of median search using quickselect algorithm

Latest version **1.0.1** (published 2016-11-27) · ISC license · 0 weekly downloads

## Install

```sh
npm install median-quickselect
pnpm add median-quickselect
yarn add median-quickselect
bun add median-quickselect
```

## Health

**Score 15/100 (F)** — status: abandoned.

Positive: no vulnerabilities.

Warnings: low downloads; no types; no esm support.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 1.0.1 |
| Published | 2016-11-27 |
| First published | 2016-11-23 |
| Weekly downloads | 0 |
| License | ISC |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 0 |
| Known vulnerabilities | 0 |
| Install scripts | no |
| Author | https://github.com/mad-gooze |
| Maintainers | mad_gooze |
| Keywords | median, quickselect |

## Links

- npm: https://www.npmjs.com/package/median-quickselect
- Repository: https://github.com/mad-gooze/median-quickselect
- Homepage: https://github.com/mad-gooze/median-quickselect#readme
- Issues: https://github.com/mad-gooze/median-quickselect/issues
- npm.io page: https://npm.io/package/median-quickselect

## Recent versions

- 1.0.1 (latest) — 2016-11-27
- 1.0.0 — 2016-11-23

## README

# median-quickselect
[![NPM](https://nodei.co/npm/median-quickselect.png)](https://npmjs.org/package/median-quickselect)

Fast implementation of lower median search using Quick select algorithm. Ported from [this C implementation](http://ndevilla.free.fr/median/median/src/quickselect.c).

Please read ["Fast median search: an ANSI C implementation"](http://ndevilla.free.fr/median/median/) by Nicolas Devillard for more info.

Note that result can be different from other packages, as `median-quickselect` calculates lower median, because taking an average of the two central elements requires two calls to the routine, doubling the processing time.
## Installation
Install from npm:
```shell
npm install --save median-quickselect
```
Or hot-link via [unpkg.com](https://unpkg.com/)
```html
<script src="https://unpkg.com/median-quickselect"></script>
```
## Usage
```js
const median = require('median-quickselect');
median([1, 4, 10, 2, 5, 0, -5]); // 2
```
Note that the  **order of elements ** on array passed to `median()` will be  **changed** after call.
## Benchmark
```
$ npm run bench                                                                                                                                                                       1001 ms  master 

> node test/benchmark.js

benchmarking dataset of 100 numbers
median: 0.891ms
fast-median: 0.999ms
compute-median: 0.269ms
stats-median: 0.159ms
median-quickselect: 0.230ms

benchmarking dataset of 1000 numbers
median: 0.849ms
fast-median: 1.713ms
compute-median: 0.562ms
stats-median: 0.210ms
median-quickselect: 0.204ms

benchmarking dataset of 10000 numbers
median: 6.249ms
fast-median: 9.413ms
compute-median: 5.816ms
stats-median: 5.101ms
median-quickselect: 2.027ms

benchmarking dataset of 1000000 numbers
median: 576.688ms
fast-median: 886.843ms
compute-median: 786.714ms
stats-median: 662.177ms
median-quickselect: 13.027ms

benchmarking dataset of 10000000 numbers
median: 6347.193ms
fast-median: 8722.377ms
compute-median: 7278.490ms
stats-median: 7089.452ms
median-quickselect: 119.298ms
```

---
_Source: https://npm.io/package/median-quickselect · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._