\begin{Schunk}
\begin{Sinput}
 m1 <- lm(y ~ x1 * x2, data=dat)
 m1.data <- model.data(m1)
 head(m1.data)
\end{Sinput}
\begin{Soutput}
         y       x1       x2
1 18.27849 45.63150 59.14025
2 15.46292 27.59503 46.79760
3 26.10437 57.24544 45.59422
4 26.54034 58.57614 53.67368
5 19.20551 65.67469 44.36610
6 17.49311 52.56795 57.85813
\end{Soutput}
\end{Schunk}
