StatsOne.txt

\subsection{Using Packages}

\begin{itemize}
\item \texttt{install.packages()}
\item \texttt{library()}
\end{itemize}

Suppose we wish to use the \textbf{emph{caret}} package for some statistical analyses.
As this package is not part of the base \texttt{R} installation, we must install it. 
We use the \texttt{install.packages()} command to perform this operation. 

(N.B. notice the use of the plural packages,as this function may be used for downloading several packages simultaneously,
 and also the use of the quotation marks.)

Some options will be presented to the user, in particular, the choice of CRAN mirror. 

Simply select the mirror of the country you are in, or nearest too.

Some packages require the last version of \texttt{R} to be installed. This problem is usually avoided
by regularly updating your version of \texttt{R} on an ongoing basis.

The package may be installed on your PC, but that does not mean that \texttt{R} may use that package.
The package must be called using the \texttt{library()} command (this time not using quotation marks)

\begin{framed}
\begin{verbatim}
install.packages("caret")
library(caret)
\end{verbatim}
\end{framed}

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