\section{SPEYE Sparse Identity Matrix}

\subsection{Usage}

Creates a sparse identity matrix of the given size.  The syntax for
its use is
\begin{verbatim}
  y = speye(m,n)
\end{verbatim}
which forms an \verb|m x n| sparse matrix with ones on the main diagonal,
or
\begin{verbatim}
  y = speye(n)
\end{verbatim}
which forms an \verb|n x n| sparse matrix with ones on the main diagonal.  The
matrix type is a \verb|float| single precision matrix.
\subsection{Example}

The following creates a 5000 by 5000 identity matrix, which would be
difficult to do using \verb|sparse(eye(5000))| because of the large amount
of intermediate storage required.
\begin{verbatim}
--> I = speye(5000)

I = 
	Matrix is sparse with 5000 nonzeros
--> full(I(1:10,1:10))

ans = 

 1 0 0 0 0 0 0 0 0 0 
 0 1 0 0 0 0 0 0 0 0 
 0 0 1 0 0 0 0 0 0 0 
 0 0 0 1 0 0 0 0 0 0 
 0 0 0 0 1 0 0 0 0 0 
 0 0 0 0 0 1 0 0 0 0 
 0 0 0 0 0 0 1 0 0 0 
 0 0 0 0 0 0 0 1 0 0 
 0 0 0 0 0 0 0 0 1 0 
 0 0 0 0 0 0 0 0 0 1 


\end{verbatim}
