\begin{Schunk}
\begin{Sinput}
 # The $ accessor
 f1 <- swiss$Fertility
 # matrix style, choose column 1
 f2 <- swiss[ , 1]
 # By column name (my favorite)
 f3 <- swiss[ , "Fertility"]
 all.equal(f1, f2, f3)
\end{Sinput}
\begin{Soutput}
[1] TRUE
\end{Soutput}
\end{Schunk}
