C# Класс AForge.Neuro.SigmoidFunction

Sigmoid activation function.

The class represents sigmoid activation function with the next expression: 1 f(x) = ------------------ 1 + exp(-alpha * x) alpha * exp(-alpha * x ) f'(x) = ---------------------------- = alpha * f(x) * (1 - f(x)) (1 + exp(-alpha * x))^2

Output range of the function: [0, 1].

Functions graph:

Наследование: IActivationFunction

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Открытые методы

Метод	Описание
Clone ( ) : object	Creates a new object that is a copy of the current instance.
Derivative ( double x ) : double	Calculates function derivative. The method calculates function derivative at point x.
Derivative2 ( double y ) : double	Calculates function derivative. The method calculates the same derivative value as the Derivative method, but it takes not the input x value itself, but the function value, which was calculated previously with the help of Function method. Some applications require as function value, as derivative value, so they can save the amount of calculations using this method to calculate derivative.
Function ( double x ) : double	Calculates function value. The method calculates function value at point x.
SigmoidFunction ( ) : System	Initializes a new instance of the SigmoidFunction class.
SigmoidFunction ( double alpha ) : System	Initializes a new instance of the SigmoidFunction class.

Описание методов

Clone() публичный метод

Creates a new object that is a copy of the current instance.

public Clone ( ) : object
Результат	object

Derivative() публичный метод

Calculates function derivative.

The method calculates function derivative at point x.

public Derivative ( double x ) : double
x	double	Function input value.
Результат	double

Derivative2() публичный метод

Calculates function derivative.

The method calculates the same derivative value as the Derivative method, but it takes not the input x value itself, but the function value, which was calculated previously with the help of Function method.

Some applications require as function value, as derivative value, so they can save the amount of calculations using this method to calculate derivative.

public Derivative2 ( double y ) : double
y	double	Function output value - the value, which was obtained /// with the help of method.
Результат	double

Function() публичный метод

Calculates function value.

The method calculates function value at point x.

public Function ( double x ) : double
x	double	Function input value.
Результат	double

SigmoidFunction() публичный метод

Initializes a new instance of the SigmoidFunction class.

public SigmoidFunction ( ) : System
Результат	System

SigmoidFunction() публичный метод

Initializes a new instance of the SigmoidFunction class.

public SigmoidFunction ( double alpha ) : System
alpha	double	Sigmoid's alpha value.
Результат	System