MathPHP\Functions\Special::logistic PHP Метод

https://en.wikipedia.org/wiki/Logistic_function L f(x) = ----------- 1 + ℯ⁻ᵏ⁽ˣ⁻ˣ⁰⁾

public static logistic ( number $x₀, number $L, number $k, number $x ) : float
$x₀	number	x-value of the sigmoid's midpoint
$L	number	the curve's maximum value
$k	number	the steepness of the curve
$x	number
Результат	float

    public static function logistic($x₀, $L, $k, $x)
    {
        $ℯ⁻ᵏ⁽ˣ⁻ˣ⁰⁾ = exp(-$k * ($x - $x₀));
        return $L / (1 + $ℯ⁻ᵏ⁽ˣ⁻ˣ⁰⁾);
    }

Special