\Header{Loblolly}{Growth of Loblolly pine trees}
\keyword{datasets}{Loblolly}
\begin{Description}\relax
The \code{Loblolly} data frame has 84 rows and 3 columns of records
of the growth of Loblolly pine trees.\end{Description}
\begin{Format}\relax
This data frame contains the following columns:
\describe{
\item[height] a numeric vector of tree heights (ft).

\item[age] a numeric vector of tree ages (yr).

\item[Seed] an ordered factor indicating the seed source for the tree.
The ordering is according to increasing maximum height.

}\end{Format}
\begin{Source}\relax
Kung, F. H. (1986), ``Fitting logistic growth curve with
predetermined carrying capacity'', \emph{Proceedings of the
Statistical Computing Section, American Statistical
Association}, 340--343.

Pinheiro, J. C. and Bates, D. M. (2000) \emph{Mixed-effects Models
in S and S-PLUS}, Springer.\end{Source}
\begin{Examples}
\begin{ExampleCode}
data(Loblolly)
plot(height ~ age, data = Loblolly, subset = Seed == 329,
     xlab = "Tree age (yr)", las = 1,
     ylab = "Tree height (ft)",
     main = "Loblolly data and fitted curve (Seed 329 only)")
fm1 <- nls(height ~ SSasymp(age, Asym, R0, lrc),
           data = Loblolly, subset = Seed == 329)
summary(fm1)
age <- seq(0, 30, len = 101)
lines(age, predict(fm1, list(age = age)))
\end{ExampleCode}
\end{Examples}

