\begin{Schunk}
\begin{Sinput}
 dat <- readRDS(file = "data/smtest.rds")
 str(dat)
\end{Sinput}
\begin{Soutput}
'data.frame':	48 obs. of  4 variables:
 $ x: num  235.7 35.3 52 415.7 412.2 ...
 $ y: int  11 14 15 10 17 10 15 14 10 8 ...
 $ w: chr  "g" "f" "i" "h" ...
 $ z: Factor w/ 4 levels "eenie","meanie",..: 1 1 1 1 1 1 1 1 1 1 ...
\end{Soutput}
\begin{Sinput}
 dat.orig <- dat ## spare copy
\end{Sinput}
\end{Schunk}
