\section{PI Constant Pi}

\subsection{Usage}

Returns a \verb|double| (64-bit floating point number) value that represents pi (ratio between the circumference and diameter of a circle...).  Typical usage 
\begin{verbatim}
   y = pi
\end{verbatim}
This value is approximately 3.141592653589793.
\subsection{Example}

The following example demonstrates the use of the \verb|pi| function.
\begin{verbatim}
--> pi
ans = 
  <double>  - size: [1 1]
 3.141592653589793  
--> cos(pi)
ans = 
  <double>  - size: [1 1]
 -1  

\end{verbatim}
