MathPHP\Probability\Distribution\Continuous\Laplace::PDF PHP Метод

    public static function PDF($x, $μ, $b) : float
    {
        Support::checkLimits(self::LIMITS, ['x' => $x, 'μ' => $μ, 'b' => $b]);
        return 1 / (2 * $b) * exp(-(abs($x - $μ) / $b));
    }