The softsign function, defined by. More...

Static Public Member Functions
static double	Deriv (const double y)
	Computes the first derivative of the softsign function. More...

template<typename InputVecType , typename OutputVecType >
static void	Deriv (const InputVecType &y, OutputVecType &x)
	Computes the first derivatives of the softsign function. More...

static double	Fn (const double x)
	Computes the softsign function. More...

template<typename InputVecType , typename OutputVecType >
static void	Fn (const InputVecType &x, OutputVecType &y)
	Computes the softsign function. More...

static double	Inv (const double y)
	Computes the inverse of the softsign function. More...

template<typename InputVecType , typename OutputVecType >
static void	Inv (const InputVecType &y, OutputVecType &x)
	Computes the inverse of the softsign function. More...

Detailed Description

The softsign function, defined by.

$\begin{eqnarray*} f(x) &=& \frac{x}{1 + |x|} \\ f'(x) &=& (1 - |f(x)|)^2 \\ f(x) &=& \left\{ \begin{array}{lr} -\frac{x}{1 - x} & : x \le 0 \\ \frac{x}{1 + x} & : x > 0 \end{array} \right. \end{eqnarray*}$

Definition at line 47 of file softsign_function.hpp.

Member Function Documentation

static double Deriv ( const double y )

inlinestatic

Computes the first derivative of the softsign function.

Parameters

y	Input activation.

Returns: f'(x)

Definition at line 84 of file softsign_function.hpp.

static void Deriv	(	const InputVecType &	y,
		OutputVecType &	x
	)

inlinestatic

Computes the first derivatives of the softsign function.

Parameters

y	Input activations.
x	The resulting derivatives.

Definition at line 96 of file softsign_function.hpp.

static double Fn ( const double x )

inlinestatic

Computes the softsign function.

Parameters

x	Input data.

Returns: f(x).

Definition at line 56 of file softsign_function.hpp.

Referenced by SoftsignFunction::Fn().

static void Fn	(	const InputVecType &	x,
		OutputVecType &	y
	)

inlinestatic

Computes the softsign function.

Parameters

x	Input data.
y	The resulting output activation.

Definition at line 70 of file softsign_function.hpp.

References SoftsignFunction::Fn().

static double Inv ( const double y )

inlinestatic

Computes the inverse of the softsign function.

Parameters

y	Input data.

Returns: f^{-1}(y)

Definition at line 107 of file softsign_function.hpp.

Referenced by SoftsignFunction::Inv().

static void Inv	(	const InputVecType &	y,
		OutputVecType &	x
	)

inlinestatic

Computes the inverse of the softsign function.

Parameters

y	Input data.
x	The resulting inverse of the input data.

Definition at line 122 of file softsign_function.hpp.

References SoftsignFunction::Inv().

The documentation for this class was generated from the following file:

src/mlpack/methods/ann/activation_functions/softsign_function.hpp

Static Public Member Functions

Detailed Description

Member Function Documentation