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SoftsignFunction Class Reference

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
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
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
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

◆ Deriv() [1/2]

static double Deriv ( const double  y)
inlinestatic

Computes the first derivative of the softsign function.

Parameters
yInput activation.
Returns
f'(x)

Definition at line 84 of file softsign_function.hpp.

◆ Deriv() [2/2]

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

Computes the first derivatives of the softsign function.

Parameters
yInput activations.
xThe resulting derivatives.

Definition at line 96 of file softsign_function.hpp.

◆ Fn() [1/2]

static double Fn ( const double  x)
inlinestatic

Computes the softsign function.

Parameters
xInput data.
Returns
f(x).

Definition at line 56 of file softsign_function.hpp.

Referenced by SoftsignFunction::Fn().

◆ Fn() [2/2]

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

Computes the softsign function.

Parameters
xInput data.
yThe resulting output activation.

Definition at line 70 of file softsign_function.hpp.

References SoftsignFunction::Fn().

◆ Inv() [1/2]

static double Inv ( const double  y)
inlinestatic

Computes the inverse of the softsign function.

Parameters
yInput data.
Returns
f^{-1}(y)

Definition at line 107 of file softsign_function.hpp.

Referenced by SoftsignFunction::Inv().

◆ Inv() [2/2]

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

Computes the inverse of the softsign function.

Parameters
yInput data.
xThe 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:
  • /home/jenkins-mlpack/mlpack.org/_src/mlpack-3.4.2/src/mlpack/methods/ann/activation_functions/softsign_function.hpp