https://github.com/derhuerst/live-moving-average

An ever updating average of the last n values.
https://github.com/derhuerst/live-moving-average

average mean moving rolling window

Last synced: 6 months ago
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An ever updating average of the last n values.

• Host: GitHub
• URL: https://github.com/derhuerst/live-moving-average
• Owner: derhuerst
• License: isc
• Created: 2017-09-10T14:14:16.000Z (about 8 years ago)
• Default Branch: master
• Last Pushed: 2022-02-13T16:35:14.000Z (over 3 years ago)
• Last Synced: 2025-04-15T05:17:22.705Z (6 months ago)
• Topics: average, mean, moving, rolling, window
• Language: JavaScript
• Homepage: https://github.com/derhuerst/live-moving-average
• Size: 14.6 KB
• Stars: 5
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: readme.md
  • License: license.md

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README

          
# live-moving-average

**An ever updating average of the last n values.** See [Moving Average](https://en.wikipedia.org/wiki/Moving_average).

[![npm version](https://img.shields.io/npm/v/live-moving-average.svg)](https://www.npmjs.com/package/live-moving-average)

[![build status](https://api.travis-ci.org/derhuerst/live-moving-average.svg?branch=master)](https://travis-ci.org/derhuerst/live-moving-average)

![ISC-licensed](https://img.shields.io/github/license/derhuerst/live-moving-average.svg)

![minimum Node.js version](https://img.shields.io/node/v/live-moving-average.svg)

[![chat with me on Gitter](https://img.shields.io/badge/chat%20with%20me-on%20gitter-512e92.svg)](https://gitter.im/derhuerst)

[![support me via GitHub Sponsors](https://img.shields.io/badge/support%20me-donate-fa7664.svg)](https://github.com/sponsors/derhuerst)

Reuses the values array to prevent GC-thrashing. Does not slow down with an increasing window size:

```window size 10, 1 push, 1 get x 65,514,574 ops/sec ±0.62% (90 runs sampled)

window size 10, 1 push, 10 get x 49,988,485 ops/sec ±0.28% (93 runs sampled)

window size 1000, 1 push, 1 get x 64,048,288 ops/sec ±0.42% (93 runs sampled)

window size 100, 1 push, 10 get x 49,012,149 ops/sec ±0.40% (95 runs sampled)

```

## Installing

```shell

npm install live-moving-average

```

## Usage

```js

const createWindow = require('live-moving-average')

const avg = createWindow(3, 0) // size of 3, fill with 0

// using api fluently

avg

    .push(2)

    .push(3)

    .push(4)

    .get() // 3, because (2 + 3 + 4) / 3

avg.push(5)

avg.push(6)

avg.get() // 5, because (4 + 5 + 6) / 3

avg.push(7)

avg.get() // 6, because (5 + 6 + 7) / 3

```

## API

### `const w = createWindow(size, fill = 0)`

`size` and `fill` must be a number.

### `w.push(val)`

`val` must be a number.    

Returns `w`.

### `w.get()`

Returns the moving average.

## Contributing

If you have a question or need support using `live-moving-average`, please double-check your code and setup first. If you think you have found a bug or want to propose a feature, use [the issues page](https://github.com/derhuerst/live-moving-average/issues).