\section{INV Invert Matrix}

\subsection{Usage}

Inverts the argument matrix, provided it is square and invertible.
The syntax for its use is
\begin{verbatim}
   y = inv(x)
\end{verbatim}
Internally, the \verb|inv| function uses the matrix divide operators.
For sparse matrices, a sparse matrix solver is used.
\subsection{Example}

Here we invert some simple matrices
\begin{verbatim}
--> a = randi(zeros(3),5*ones(3))

a = 

 1 1 4 
 1 0 1 
 0 4 1 

--> b = inv(a)

b = 

   -0.3636    1.3636    0.0909 
   -0.0909    0.0909    0.2727 
    0.3636   -0.3636   -0.0909 

--> a*b

ans = 

    1.0000    0.0000         0 
         0    1.0000    0.0000 
         0         0    1.0000 

--> b*a

ans = 

    1.0000    0.0000    0.0000 
         0    1.0000   -0.0000 
         0         0    1.0000 


\end{verbatim}
