\section{F1$<$ AS, Positive\+Class $>$ Class Template Reference}
\label{classmlpack_1_1cv_1_1F1}\index{F1$<$ A\+S, Positive\+Class $>$@{F1$<$ A\+S, Positive\+Class $>$}}


\doxyref{F1}{p.}{classmlpack_1_1cv_1_1F1} is a metric of performance for classification algorithms that for binary classification is equal to $ 2 * precision * recall / (precision + recall) $.  


\subsection*{Static Public Member Functions}
\begin{DoxyCompactItemize}
\item 
{\footnotesize template$<$typename M\+L\+Algorithm , typename Data\+Type $>$ }\\static double \textbf{ Evaluate} (M\+L\+Algorithm \&model, const Data\+Type \&data, const arma\+::\+Row$<$ size\+\_\+t $>$ \&labels)
\begin{DoxyCompactList}\small\item\em Run classification and calculate \doxyref{F1}{p.}{classmlpack_1_1cv_1_1F1}. \end{DoxyCompactList}\end{DoxyCompactItemize}
\subsection*{Static Public Attributes}
\begin{DoxyCompactItemize}
\item 
static const bool \textbf{ Needs\+Minimization} = false
\begin{DoxyCompactList}\small\item\em Information for hyper-\/parameter tuning code. \end{DoxyCompactList}\end{DoxyCompactItemize}


\subsection{Detailed Description}
\subsubsection*{template$<$Average\+Strategy AS, size\+\_\+t Positive\+Class = 1$>$\newline
class mlpack\+::cv\+::\+F1$<$ A\+S, Positive\+Class $>$}

\doxyref{F1}{p.}{classmlpack_1_1cv_1_1F1} is a metric of performance for classification algorithms that for binary classification is equal to $ 2 * precision * recall / (precision + recall) $. 

For multiclass classification the \doxyref{F1}{p.}{classmlpack_1_1cv_1_1F1} metric can be used with the following strategies for averaging.
\begin{DoxyEnumerate}
\item Micro. The result is calculated by the above formula, but microaveraged precision and microaveraged recall are used.
\item Macro. \doxyref{F1}{p.}{classmlpack_1_1cv_1_1F1} is calculated for each class (with values used for calculation of macroaveraged precision and macroaveraged recall), and then the \doxyref{F1}{p.}{classmlpack_1_1cv_1_1F1} values are averaged.
\end{DoxyEnumerate}

In the case of multiclass classification it is assumed that there are instances of every label from 0 to max(labels) among input data points.

The returned value for \doxyref{F1}{p.}{classmlpack_1_1cv_1_1F1} will be zero if both precision and recall turn out to be zeros.


\begin{DoxyTemplParams}{Template Parameters}
{\em AS} & An average strategy. \\
\hline
{\em Positive\+Class} & In the case of binary classification (AS = Binary) positives are assumed to have labels equal to this value. \\
\hline
\end{DoxyTemplParams}


Definition at line 45 of file f1.\+hpp.



\subsection{Member Function Documentation}
\mbox{\label{classmlpack_1_1cv_1_1F1_a77b6a9eb952b01bfc5c0d854da700465}} 
\index{mlpack\+::cv\+::\+F1@{mlpack\+::cv\+::\+F1}!Evaluate@{Evaluate}}
\index{Evaluate@{Evaluate}!mlpack\+::cv\+::\+F1@{mlpack\+::cv\+::\+F1}}
\subsubsection{Evaluate()}
{\footnotesize\ttfamily static double Evaluate (\begin{DoxyParamCaption}\item[{M\+L\+Algorithm \&}]{model,  }\item[{const Data\+Type \&}]{data,  }\item[{const arma\+::\+Row$<$ size\+\_\+t $>$ \&}]{labels }\end{DoxyParamCaption})\hspace{0.3cm}{\ttfamily [static]}}



Run classification and calculate \doxyref{F1}{p.}{classmlpack_1_1cv_1_1F1}. 


\begin{DoxyParams}{Parameters}
{\em model} & A classification model. \\
\hline
{\em data} & Column-\/major data containing test items. \\
\hline
{\em labels} & Ground truth (correct) labels for the test items. \\
\hline
\end{DoxyParams}


\subsection{Member Data Documentation}
\mbox{\label{classmlpack_1_1cv_1_1F1_a59117419810548f86c24651ffa3500d5}} 
\index{mlpack\+::cv\+::\+F1@{mlpack\+::cv\+::\+F1}!Needs\+Minimization@{Needs\+Minimization}}
\index{Needs\+Minimization@{Needs\+Minimization}!mlpack\+::cv\+::\+F1@{mlpack\+::cv\+::\+F1}}
\subsubsection{Needs\+Minimization}
{\footnotesize\ttfamily const bool Needs\+Minimization = false\hspace{0.3cm}{\ttfamily [static]}}



Information for hyper-\/parameter tuning code. 

It indicates that we want to maximize the metric. 

Definition at line 64 of file f1.\+hpp.



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.\+1/src/mlpack/core/cv/metrics/\textbf{ f1.\+hpp}\end{DoxyCompactItemize}