JarCastingerfinv
The inverse error function is defined in terms of the Maclaurin series
where c_0 = 1 and
Installation
$ npm install math-erfinv
Usage
var erfinv = require( 'math-erfinv' );
erfinv( x )
Evaluates the inverse error function.
var y = erfinv( 0.5 );
// returns ~0.4769
y = erfinv( 0.8 );
// returns ~0.9062
y = erfinv( -1 );
// returns -infinity
y = erfinv( 1 );
// returns +infinity
The domain of x is restricted to [-1,1]. If |x| > 1, the function will throw a RangeError.
var y = erfinv( -3.14 );
// throws <Error>
If provided NaN, the function returns NaN.
var y = erfinv( NaN );
// returns NaN
The inverse error function is an odd function; i.e., erfinv(-x) = -erfinv(x). Thus, in accordance with the IEEE 754 standard, if provided -0, the function returns -0.
var y = erfinv( -0 );
// returns -0
Examples
var linspace = require( 'compute-linspace' );
var erfinv = require( 'math-erfinv' );
var x = linspace( -1, 1, 100 );
var y;
var i;
for ( i = 0; i < x.length; i++ ) {
y = erfinv( x[ i ] );
console.log( 'x: %d, erfinv(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
Copyright
Copyright © 2016. The Compute.io Authors.
