gammaln

Natural logarithm of the gamma function.

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

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

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