\begin{Schunk}
\begin{Sinput}
 (N-1) * Sigma
\end{Sinput}
\begin{Soutput}
       [,1]    [,2]    [,3]    [,4]
[1,]  999.0   999.0  4195.8  2797.2
[2,]  999.0  3996.0 -1398.6   799.2
[3,] 4195.8 -1398.6 48951.0  5594.4
[4,] 2797.2   799.2  5594.4 15984.0
\end{Soutput}
\end{Schunk}
