MathPHP\Statistics\Average::logarithmicMean PHP Method

    public static function logarithmicMean($x, $y)
    {
        if ($x == 0 || $y == 0) {
            return 0;
        }
        if ($x == $y) {
            return $x;
        }
        return ($y - $x) / (log($y) - log($x));
    }