Bipolar sigmoid activation function.

Namespace:  AForge.Neuro
Assembly:  AForge.Neuro (in AForge.Neuro.dll) Version: 2.2.4.0 (2.2.4.0)

Syntax

C#
[SerializableAttribute]
public class BipolarSigmoidFunction : IActivationFunction

Remarks

The class represents bipolar sigmoid activation function with the next expression:

Copy 
               2
f(x) = ------------------ - 1
       1 + exp(-alpha * x)

          2 * alpha * exp(-alpha * x )
f'(x) = -------------------------------- = alpha * (1 - f(x)^2) / 2
          (1 + exp(-alpha * x))^2

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

Functions graph:

Inheritance Hierarchy

System..::.Object
  AForge.Neuro..::.BipolarSigmoidFunction

See Also