Computes a moving sample variance over a numeric array.
npm install compute-mvarianceMoving Sample Variance
===
[![NPM version][npm-image]][npm-url] [![Build Status][travis-image]][travis-url] [![Coverage Status][coveralls-image]][coveralls-url] [![Dependencies][dependencies-image]][dependencies-url]
> Computes a moving (sliding window) sample variance over a numeric array.
`` bash`
$ npm install compute-mvariance
For use in the browser, use browserify.
To use the module,
` javascript`
var mvariance = require( 'compute-mvariance' );
#### mvariance( arr, window )
Slides a window over a numeric array to compute a moving sample variance.
` javascript
var data = [ 1, 5, 0, 10, 2 ];
var arr = mvariance( data, 3 );
// returns [ 7, 25, 28 ]
`
Note: the returned array has length L - W + 1, where L is the length of the input array and W is the window size.
` javascript
var mvariance = require( 'compute-mvariance' );
// Simulate some data...
var data = new Array( 50 );
for ( var i = 0; i < data.length; i++ ) {
data[ i ] = Math.random() * 100;
}
// Compute the moving sample variance:
var arr = mvariance( data, 7 );
console.log( arr.join( '\n' ) );
`
To run the example code from the top-level application directory,
` bash`
$ node ./examples/index.js
Unit tests use the Mocha test framework with Chai assertions. To run the tests, execute the following command in the top-level application directory:
` bash`
$ make test
All new feature development should have corresponding unit tests to validate correct functionality.
This repository uses Istanbul as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:
` bash`
$ make test-cov
Istanbul creates a ./reports/coverage directory. To access an HTML version of the report,
` bash``
$ make view-cov
---
Copyright © 2014. Athan Reines.
[npm-image]: http://img.shields.io/npm/v/compute-mvariance.svg
[npm-url]: https://npmjs.org/package/compute-mvariance
[travis-image]: http://img.shields.io/travis/compute-io/mvariance/master.svg
[travis-url]: https://travis-ci.org/compute-io/mvariance
[coveralls-image]: https://img.shields.io/coveralls/compute-io/mvariance/master.svg
[coveralls-url]: https://coveralls.io/r/compute-io/mvariance?branch=master
[dependencies-image]: http://img.shields.io/david/compute-io/mvariance.svg
[dependencies-url]: https://david-dm.org/compute-io/mvariance
[dev-dependencies-image]: http://img.shields.io/david/dev/compute-io/mvariance.svg
[dev-dependencies-url]: https://david-dm.org/dev/compute-io/mvariance
[github-issues-image]: http://img.shields.io/github/issues/compute-io/mvariance.svg
[github-issues-url]: https://github.com/compute-io/mvariance/issues