\HeaderA{oats}{Data from an Oats Field Trial}{oats}
\keyword{datasets}{oats}
\begin{Description}\relax
The yield of oats from a split-plot field trial using three varieties and
four levels of manurial treatment.  The experiment was laid out in 6 blocks
of 3 main plots, each split into 4 sub-plots.  The varieties were applied
to the main plots and the manurial treatments to the sub-plots.
\end{Description}
\begin{Usage}
\begin{verbatim}
oats
\end{verbatim}
\end{Usage}
\begin{Format}\relax
This data frame contains the following columns:
\describe{
\item[\code{B}] Blocks, levels I, II, III, IV, V and VI

\item[\code{V}] Varieties, 3 levels.

\item[\code{N}] Nitrogen (manurial) treatment, levels  0.0cwt, 0.2cwt, 0.4cwt and 0.6cwt,
showing the application in cwt/acre.

\item[\code{Y}] Yields in 1/4lbs per sub-plot, each of area 1/80 acre.
}
\end{Format}
\begin{Source}\relax
Yates, F. (1935) Complex experiments,
\emph{Journal of the Royal Statistical Society Suppl.}
\bold{2}, 181--247.

Also given in
Yates, F. (1970)
\emph{Experimental design: Selected papers of Frank Yates, C.B.E, F.R.S.}
London: Griffin.
\end{Source}
\begin{References}\relax
Venables, W. N. and Ripley, B. D. (2002)
\emph{Modern Applied Statistics with S.} Fourth edition.  Springer.
\end{References}
\begin{Examples}
\begin{ExampleCode}
oats$Nf <- ordered(oats$N, levels = sort(levels(oats$N)))
oats.aov <- aov(Y ~ Nf*V + Error(B/V), data = oats, qr = TRUE)
summary(oats.aov)
summary(oats.aov, split = list(Nf=list(L=1, Dev=2:3)))
par(mfrow = c(1,2), pty = "s")
plot(fitted(oats.aov[[4]]), studres(oats.aov[[4]]))
abline(h = 0, lty = 2)
oats.pr <- proj(oats.aov)
qqnorm(oats.pr[[4]][,"Residuals"], ylab = "Stratum 4 residuals")
qqline(oats.pr[[4]][,"Residuals"])

par(mfrow = c(1,1), pty = "m")
oats.aov2 <- aov(Y ~ N + V + Error(B/V), data = oats, qr = TRUE)
model.tables(oats.aov2, type = "means", se = TRUE)
\end{ExampleCode}
\end{Examples}