npm install math-erferf
===
[![NPM version][npm-image]][npm-url] [![Build Status][build-image]][build-url] [![Coverage Status][coverage-image]][coverage-url] [![Dependencies][dependencies-image]][dependencies-url]
> [Error function][error-function].
The [error function][error-function] is defined as
Installation
`` bash`
$ npm install math-erf
Usage
` javascript`
var erf = require( 'math-erf' );
#### erf( x )
Evaluates the [error function][error-function].
` javascript
var y = erf( 2 );
// returns ~0.9953
y = erf( -1 );
// returns ~-0.8427
`
If provided NaN, the function returns NaN.
` javascript`
var y = erf( NaN );
// returns NaN
The [error function][error-function] is an [odd function][odd-function]; i.e., erf(-x) = -erf(x). Thus, in accordance with the [IEEE 754][ieee754] standard, if provided -0, the function returns -0.
` javascript`
var y = erf( -0 );
// returns -0
Examples
` javascript
var linspace = require( 'compute-linspace' );
var erf = require( 'math-erf' );
var x = linspace( -10, 10, 100 );
var y;
var i;
for ( i = 0; i < x.length; i++ ) {
y = erf( x[ i ] );
console.log( 'x: %d, erf(x): %d', x[ i ], y );
}
`
To run the example code from the top-level application directory,
` bash`
$ node ./examples/index.js
---
Tests
$3
This repository uses [tape][tape] for unit tests. 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.
$3
This repository uses [Istanbul][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
$3
This repository uses [Testling][testling] for browser testing. To run the tests in a (headless) local web browser, execute the following command in the top-level application directory:
` bash`
$ make test-browsers
To view the tests in a local web browser,
` bash``
$ make view-browser-tests
---
License
Copyright
Copyright © 2016. The [Compute.io][compute-io] Authors.
[npm-image]: http://img.shields.io/npm/v/math-erf.svg
[npm-url]: https://npmjs.org/package/math-erf
[build-image]: http://img.shields.io/travis/math-io/erf/master.svg
[build-url]: https://travis-ci.org/math-io/erf
[coverage-image]: https://img.shields.io/codecov/c/github/math-io/erf/master.svg
[coverage-url]: https://codecov.io/github/math-io/erf?branch=master
[dependencies-image]: http://img.shields.io/david/math-io/erf.svg
[dependencies-url]: https://david-dm.org/math-io/erf
[dev-dependencies-image]: http://img.shields.io/david/dev/math-io/erf.svg
[dev-dependencies-url]: https://david-dm.org/dev/math-io/erf
[github-issues-image]: http://img.shields.io/github/issues/math-io/erf.svg
[github-issues-url]: https://github.com/math-io/erf/issues
[tape]: https://github.com/substack/tape
[istanbul]: https://github.com/gotwarlost/istanbul
[testling]: https://ci.testling.com
[compute-io]: https://github.com/compute-io/
[error-function]: https://en.wikipedia.org/wiki/Error_function
[odd-function]: https://en.wikipedia.org/wiki/Even_and_odd_functions
[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985