erf

Error function.

The error function is defined as

Installation

$ npm install math-erf

Usage

var erf = require( 'math-erf' );

erf( x )

Evaluates the error function.

var y = erf( 2 );
// returns ~0.9953

y = erf( -1 );
// returns ~-0.8427

If provided NaN, the function returns NaN.

var y = erf( NaN );
// returns NaN

The error function is an odd function; i.e., erf(-x) = -erf(x). Thus, in accordance with the IEEE 754 standard, if provided -0, the function returns -0.

var y = erf( -0 );
// returns -0

Examples

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,

$ node ./examples/index.js

---

Tests

Unit

This repository uses tape for unit tests. To run the tests, execute the following command in the top-level application directory:

$ make test

All new feature development should have corresponding unit tests to validate correct functionality.

Test Coverage

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:

$ make test-cov

Istanbul creates a ./reports/coverage directory. To access an HTML version of the report,

$ make view-cov

Browser Support

This repository uses Testling for browser testing. To run the tests in a (headless) local web browser, execute the following command in the top-level application directory:

$ make test-browsers

To view the tests in a local web browser,

$ make view-browser-tests

---

License

MIT license.

Copyright

Copyright © 2016. The Compute.io Authors.