\section{CLOCKTOTIME Convert Clock Vector to Epoch Time}

\subsection{Usage}

Given the output of the \verb|clock| command, this function computes
the epoch time, i.e, the time in seconds since January 1,1970 
at 00:00:00 UTC.  This function is most useful for calculating elapsed
times using the clock, and should be accurate to less than a millisecond
(although the true accuracy depends on accuracy of the argument vector). 
The usage for \verb|clocktotime| is
\begin{verbatim}
   y = clocktotime(x)
\end{verbatim}
where \verb|x| must be in the form of the output of \verb|clock|, that is
\begin{verbatim}
   x = [year month day hour minute seconds]
\end{verbatim}
\subsection{Example}

Here is an example of using \verb|clocktotime| to time a delay of 1 second
\begin{verbatim}
--> x = clock
x = 
  <double>  - size: [1 6]
 
Columns 1 to 6
 2007.0     4.0    13.0    21.0    37.0    32.2  
--> sleep(1)
--> y = clock
y = 
  <double>  - size: [1 6]
 
Columns 1 to 6
 2007.00     4.00    13.00    21.00    37.00    33.21  
--> clocktotime(y) - clocktotime(x)
ans = 
  <double>  - size: [1 1]
 1.0099999904632568  

\end{verbatim}
