MathPHP\Probability\Distribution\Discrete\Poisson::CDF PHP Метод

    public static function CDF(int $k, float $λ) : float
    {
        Support::checkLimits(self::LIMITS, ['k' => $k, 'λ' => $λ]);
        return array_sum(array_map(function ($k) use($λ) {
            return self::PMF($k, $λ);
        }, range(0, $k)));
    }