\section{Softsign\+Function Class Reference}
\label{classmlpack_1_1ann_1_1SoftsignFunction}\index{Softsign\+Function@{Softsign\+Function}}


The softsign function, defined by.  


\subsection*{Static Public Member Functions}
\begin{DoxyCompactItemize}
\item 
static double \textbf{ Deriv} (const double y)
\begin{DoxyCompactList}\small\item\em Computes the first derivative of the softsign function. \end{DoxyCompactList}\item 
{\footnotesize template$<$typename Input\+Vec\+Type , typename Output\+Vec\+Type $>$ }\\static void \textbf{ Deriv} (const Input\+Vec\+Type \&y, Output\+Vec\+Type \&x)
\begin{DoxyCompactList}\small\item\em Computes the first derivatives of the softsign function. \end{DoxyCompactList}\item 
static double \textbf{ Fn} (const double x)
\begin{DoxyCompactList}\small\item\em Computes the softsign function. \end{DoxyCompactList}\item 
{\footnotesize template$<$typename Input\+Vec\+Type , typename Output\+Vec\+Type $>$ }\\static void \textbf{ Fn} (const Input\+Vec\+Type \&x, Output\+Vec\+Type \&y)
\begin{DoxyCompactList}\small\item\em Computes the softsign function. \end{DoxyCompactList}\item 
static double \textbf{ Inv} (const double y)
\begin{DoxyCompactList}\small\item\em Computes the inverse of the softsign function. \end{DoxyCompactList}\item 
{\footnotesize template$<$typename Input\+Vec\+Type , typename Output\+Vec\+Type $>$ }\\static void \textbf{ Inv} (const Input\+Vec\+Type \&y, Output\+Vec\+Type \&x)
\begin{DoxyCompactList}\small\item\em Computes the inverse of the softsign function. \end{DoxyCompactList}\end{DoxyCompactItemize}


\subsection{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.



\subsection{Member Function Documentation}
\mbox{\label{classmlpack_1_1ann_1_1SoftsignFunction_a163d34fd09f8edf457164f5033c635cf}} 
\index{mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}!Deriv@{Deriv}}
\index{Deriv@{Deriv}!mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}}
\subsubsection{Deriv()\hspace{0.1cm}{\footnotesize\ttfamily [1/2]}}
{\footnotesize\ttfamily static double Deriv (\begin{DoxyParamCaption}\item[{const double}]{y }\end{DoxyParamCaption})\hspace{0.3cm}{\ttfamily [inline]}, {\ttfamily [static]}}



Computes the first derivative of the softsign function. 


\begin{DoxyParams}{Parameters}
{\em y} & Input data. \\
\hline
\end{DoxyParams}
\begin{DoxyReturn}{Returns}
f\textquotesingle{}(x) 
\end{DoxyReturn}


Definition at line 84 of file softsign\+\_\+function.\+hpp.

\mbox{\label{classmlpack_1_1ann_1_1SoftsignFunction_ad442502c34b67303b74c735641dab790}} 
\index{mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}!Deriv@{Deriv}}
\index{Deriv@{Deriv}!mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}}
\subsubsection{Deriv()\hspace{0.1cm}{\footnotesize\ttfamily [2/2]}}
{\footnotesize\ttfamily static void Deriv (\begin{DoxyParamCaption}\item[{const Input\+Vec\+Type \&}]{y,  }\item[{Output\+Vec\+Type \&}]{x }\end{DoxyParamCaption})\hspace{0.3cm}{\ttfamily [inline]}, {\ttfamily [static]}}



Computes the first derivatives of the softsign function. 


\begin{DoxyParams}{Parameters}
{\em y} & Input activations. \\
\hline
{\em x} & The resulting derivatives. \\
\hline
\end{DoxyParams}


Definition at line 96 of file softsign\+\_\+function.\+hpp.

\mbox{\label{classmlpack_1_1ann_1_1SoftsignFunction_a11bd9a1195e6b107f9fee73643bc328b}} 
\index{mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}!Fn@{Fn}}
\index{Fn@{Fn}!mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}}
\subsubsection{Fn()\hspace{0.1cm}{\footnotesize\ttfamily [1/2]}}
{\footnotesize\ttfamily static double Fn (\begin{DoxyParamCaption}\item[{const double}]{x }\end{DoxyParamCaption})\hspace{0.3cm}{\ttfamily [inline]}, {\ttfamily [static]}}



Computes the softsign function. 


\begin{DoxyParams}{Parameters}
{\em x} & Input data. \\
\hline
\end{DoxyParams}
\begin{DoxyReturn}{Returns}
f(x). 
\end{DoxyReturn}


Definition at line 56 of file softsign\+\_\+function.\+hpp.



Referenced by Softsign\+Function\+::\+Fn().

\mbox{\label{classmlpack_1_1ann_1_1SoftsignFunction_af6cf5da90eb6312e3e25c9b8bd9c3527}} 
\index{mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}!Fn@{Fn}}
\index{Fn@{Fn}!mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}}
\subsubsection{Fn()\hspace{0.1cm}{\footnotesize\ttfamily [2/2]}}
{\footnotesize\ttfamily static void Fn (\begin{DoxyParamCaption}\item[{const Input\+Vec\+Type \&}]{x,  }\item[{Output\+Vec\+Type \&}]{y }\end{DoxyParamCaption})\hspace{0.3cm}{\ttfamily [inline]}, {\ttfamily [static]}}



Computes the softsign function. 


\begin{DoxyParams}{Parameters}
{\em x} & Input data. \\
\hline
{\em y} & The resulting output activation. \\
\hline
\end{DoxyParams}


Definition at line 70 of file softsign\+\_\+function.\+hpp.



References Softsign\+Function\+::\+Fn().

\mbox{\label{classmlpack_1_1ann_1_1SoftsignFunction_a32d503b167c9646569a202e8c134ef76}} 
\index{mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}!Inv@{Inv}}
\index{Inv@{Inv}!mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}}
\subsubsection{Inv()\hspace{0.1cm}{\footnotesize\ttfamily [1/2]}}
{\footnotesize\ttfamily static double Inv (\begin{DoxyParamCaption}\item[{const double}]{y }\end{DoxyParamCaption})\hspace{0.3cm}{\ttfamily [inline]}, {\ttfamily [static]}}



Computes the inverse of the softsign function. 


\begin{DoxyParams}{Parameters}
{\em y} & Input data. \\
\hline
\end{DoxyParams}
\begin{DoxyReturn}{Returns}
f$^\wedge$\{-\/1\}(y) 
\end{DoxyReturn}


Definition at line 107 of file softsign\+\_\+function.\+hpp.



Referenced by Softsign\+Function\+::\+Inv().

\mbox{\label{classmlpack_1_1ann_1_1SoftsignFunction_ad48548410161bbf6178eb1c293c991c3}} 
\index{mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}!Inv@{Inv}}
\index{Inv@{Inv}!mlpack\+::ann\+::\+Softsign\+Function@{mlpack\+::ann\+::\+Softsign\+Function}}
\subsubsection{Inv()\hspace{0.1cm}{\footnotesize\ttfamily [2/2]}}
{\footnotesize\ttfamily static void Inv (\begin{DoxyParamCaption}\item[{const Input\+Vec\+Type \&}]{y,  }\item[{Output\+Vec\+Type \&}]{x }\end{DoxyParamCaption})\hspace{0.3cm}{\ttfamily [inline]}, {\ttfamily [static]}}



Computes the inverse of the softsign function. 


\begin{DoxyParams}{Parameters}
{\em y} & Input data. \\
\hline
{\em x} & The resulting inverse of the input data. \\
\hline
\end{DoxyParams}


Definition at line 122 of file softsign\+\_\+function.\+hpp.



References Softsign\+Function\+::\+Inv().



The documentation for this class was generated from the following file\+:\begin{DoxyCompactItemize}
\item 
/var/www/mlpack.\+ratml.\+org/mlpack.\+org/\+\_\+src/mlpack-\/3.\+3.\+0/src/mlpack/methods/ann/activation\+\_\+functions/\textbf{ softsign\+\_\+function.\+hpp}\end{DoxyCompactItemize}