Loblolly {datasets} | R Documentation |
The Loblolly
data frame has 84 rows and 3 columns of records of
the growth of Loblolly pine trees.
Loblolly
This data frame contains the following columns:
a numeric vector of tree heights (ft).
a numeric vector of tree ages (yr).
an ordered factor indicating the seed source for the tree. The ordering is according to increasing maximum height.
Kung, F. H. (1986), Fitting logistic growth curve with predetermined carrying capacity, in Proceedings of the Statistical Computing Section, American Statistical Association, 340–343.
Pinheiro, J. C. and Bates, D. M. (2000) Mixed-effects Models in S and S-PLUS, Springer.
require(stats); require(graphics)
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, length.out = 101)
lines(age, predict(fm1, list(age = age)))