\Header{Sitka89}{Growth Curves for Sitka Spruce Trees in 1989}
\keyword{datasets}{Sitka89}
\begin{Description}\relax
The \code{Sitka89} data frame has 632 rows and 4 columns.  It gives repeated
measurements on the log-size of 79 Sitka spruce trees, 54 of which
were grown in ozone-enriched chambers and 25 were controls.  The size
was measured eight times in 1989, at roughly monthly intervals.
\end{Description}
\begin{Usage}
\begin{verbatim}
data(Sitka89)
\end{verbatim}
\end{Usage}
\begin{Format}\relax
This data frame contains the following columns:
\describe{
\item[\code{size}] measured size (height times diameter squared) of tree, on log scale

\item[\code{Time}] time of measurement in  days since 1 January 1988

\item[\code{tree}] number of tree

\item[\code{treat}] either \code{"ozone"} for an ozone-enriched chamber or \code{"control"}
}
\end{Format}
\begin{Source}\relax
P. J. Diggle, K.-Y. Liang and S. L. Zeger (1994)
\emph{Analysis of Longitudinal Data.}
Clarendon Press, Oxford
\end{Source}
\begin{SeeAlso}\relax
\code{\Link{Sitka}}
\end{SeeAlso}

