\section{HORZCAT Overloaded Horizontal Concatenation}

\subsection{Usage}

This is a method for a class that is invoked to concatenate two or more
variables of the same class type together.  Besides being called
when you invoke
\begin{verbatim}
   c = horzcat(a,b,c)
\end{verbatim}
when \verb|a| is a class, it is also called for 
\begin{verbatim}
   c = [a,b,c]
\end{verbatim}
when one of these variables is a class.  The exact meaning of
horizontal concatenation depends on the class you have designed.
