https://github.com/stdlib-js/stats-incr-nanstdev
Compute a corrected sample standard deviation incrementally, ignoring NaN values.
https://github.com/stdlib-js/stats-incr-nanstdev
accumulator central-tendency corrected dispersion incremental javascript math mathematics node node-js nodejs sample-variance standard-deviation statistics stats stdlib var variance
Last synced: about 1 month ago
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Compute a corrected sample standard deviation incrementally, ignoring NaN values.
- Host: GitHub
- URL: https://github.com/stdlib-js/stats-incr-nanstdev
- Owner: stdlib-js
- License: apache-2.0
- Created: 2025-04-01T09:51:16.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2025-08-20T20:54:37.000Z (10 months ago)
- Last Synced: 2025-08-20T22:31:08.305Z (10 months ago)
- Topics: accumulator, central-tendency, corrected, dispersion, incremental, javascript, math, mathematics, node, node-js, nodejs, sample-variance, standard-deviation, statistics, stats, stdlib, var, variance
- Language: JavaScript
- Homepage: https://github.com/stdlib-js/stdlib
- Size: 218 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Citation: CITATION.cff
- Security: SECURITY.md
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README
About stdlib...
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# incrnanstdev
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> Compute a [corrected sample standard deviation][sample-stdev] incrementally, ignoring `NaN` values.
The [corrected sample standard deviation][sample-stdev] is defined as
```math
s = \sqrt{\frac{1}{n-1} \sum_{i=0}^{n-1} ( x_i - \bar{x} )^2}
```
## Installation
```bash
npm install @stdlib/stats-incr-nanstdev
```
Alternatively,
- To load the package in a website via a `script` tag without installation and bundlers, use the [ES Module][es-module] available on the [`esm`][esm-url] branch (see [README][esm-readme]).
- If you are using Deno, visit the [`deno`][deno-url] branch (see [README][deno-readme] for usage intructions).
- For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [`umd`][umd-url] branch (see [README][umd-readme]).
The [branches.md][branches-url] file summarizes the available branches and displays a diagram illustrating their relationships.
To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.
## Usage
```javascript
var incrnanstdev = require( '@stdlib/stats-incr-nanstdev' );
```
#### incrnanstdev( \[mean] )
Returns an accumulator function which incrementally computes a [corrected sample standard deviation][sample-stdev], ignoring `NaN` values.
```javascript
var accumulator = incrnanstdev();
```
If the mean is already known, provide a `mean` argument.
```javascript
var accumulator = incrnanstdev( 3.0 );
```
#### accumulator( \[x] )
If provided an input value `x`, the accumulator function returns an updated [corrected sample standard deviation][sample-stdev]. If not provided an input value `x`, the accumulator function returns the current [corrected sample standard deviation][sample-stdev].
```javascript
var accumulator = incrnanstdev();
var s = accumulator( 2.0 );
// returns 0.0
s = accumulator( 1.0 ); // => sqrt(((2-1.5)^2+(1-1.5)^2) / (2-1))
// returns ~0.7071
s = accumulator( 3.0 ); // => sqrt(((2-2)^2+(1-2)^2+(3-2)^2) / (3-1))
// returns 1.0
s = accumulator( NaN );
// returns 1.0
s = accumulator();
// returns 1.0
```
## Notes
- Input values are **not** type checked. If non-numeric inputs are possible, you are advised to type check and handle accordingly **before** passing the value to the accumulator function.
## Examples
```javascript
var uniform = require( '@stdlib/random-base-uniform' );
var bernoulli = require( '@stdlib/random-base-bernoulli' );
var incrnanstdev = require( '@stdlib/stats-incr-nanstdev' );
// Initialize an accumulator:
var accumulator = incrnanstdev();
// For each simulated datum, update the sample standard deviation...
var i;
for ( i = 0; i < 100; i++ ) {
accumulator( ( bernoulli( 0.8 ) < 1 ) ? NaN : uniform( 0.0, 100.0 ) );
}
console.log( accumulator() );
```
* * *
## Notice
This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].
#### Community
[![Chat][chat-image]][chat-url]
---
## License
See [LICENSE][stdlib-license].
## Copyright
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
[npm-image]: http://img.shields.io/npm/v/@stdlib/stats-incr-nanstdev.svg
[npm-url]: https://npmjs.org/package/@stdlib/stats-incr-nanstdev
[test-image]: https://github.com/stdlib-js/stats-incr-nanstdev/actions/workflows/test.yml/badge.svg?branch=main
[test-url]: https://github.com/stdlib-js/stats-incr-nanstdev/actions/workflows/test.yml?query=branch:main
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/stats-incr-nanstdev/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/stats-incr-nanstdev?branch=main
[chat-image]: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg
[chat-url]: https://stdlib.zulipchat.com
[stdlib]: https://github.com/stdlib-js/stdlib
[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors
[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/stats-incr-nanstdev/tree/deno
[deno-readme]: https://github.com/stdlib-js/stats-incr-nanstdev/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/stats-incr-nanstdev/tree/umd
[umd-readme]: https://github.com/stdlib-js/stats-incr-nanstdev/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/stats-incr-nanstdev/tree/esm
[esm-readme]: https://github.com/stdlib-js/stats-incr-nanstdev/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/stats-incr-nanstdev/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/stats-incr-nanstdev/main/LICENSE
[sample-stdev]: https://en.wikipedia.org/wiki/Standard_deviation