@stdlib/math-base-special-gammaln NPM

gammaln

$NPM version$ $Build Status$ $Coverage Status$

Natural logarithm of the gamma function.

Installation

npm install @stdlib/math-base-special-gammaln

Usage

var gammaln = require( '@stdlib/math-base-special-gammaln' );

gammaln( x )

Evaluates the natural logarithm of the gamma function.

var v = gammaln( 2.0 );
// returns 0.0

v = gammaln( 1.0 );
// returns 0.0

v = gammaln( 4.0 );
// returns ~1.792

v = gammaln( -0.5 );
// returns ~1.266

v = gammaln( 0.5 );
// returns ~0.572

v = gammaln( 0.0 );
// returns Infinity

v = gammaln( NaN );
// returns NaN

Examples

var linspace = require( '@stdlib/array-base-linspace' );
var gammaln = require( '@stdlib/math-base-special-gammaln' );

var x = linspace( -10.0, 10.0, 100 );

var i;
for ( i = 0; i < x.length; i++ ) {
    console.log( 'x: %d, f(x): %d', x[ i ], gammaln( x[ i ] ) );
}

Notice

This package is part of 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, see the main project repository.