\HeaderA{PlantGrowth}{Results from an Experiment on Plant Growth}{PlantGrowth}
\keyword{datasets}{PlantGrowth}
\begin{Description}\relax
Results from an experiment to compare yields (as measured by dried
weight of plants) obtained under a control and two different treatment
conditions.
\end{Description}
\begin{Usage}
\begin{verbatim}PlantGrowth\end{verbatim}
\end{Usage}
\begin{Format}\relax
A data frame of 30 cases on 2 variables.

\Tabular{rll}{
[, 1] & weight & numeric \\{}
[, 2] & group  & factor
}

The levels of \code{group} are \sQuote{ctrl}, \sQuote{trt1}, and \sQuote{trt2}.
\end{Format}
\begin{Source}\relax
Dobson, A. J. (1983)
\emph{An Introduction to Statistical Modelling}.
London: Chapman and Hall.
\end{Source}
\begin{Examples}
\begin{ExampleCode}
## One factor ANOVA example from Dobson's book, cf. Table 7.4:
require(stats)
boxplot(weight ~ group, data = PlantGrowth, main = "PlantGrowth data",
        ylab = "Dried weight of plants", col = "lightgray",
        notch = TRUE, varwidth = TRUE)
anova(lm(weight ~ group, data = PlantGrowth))
\end{ExampleCode}
\end{Examples}