Orange data frame has 35 rows and 3 columns of records of
the growth of orange trees.
An object of class
c("nfnGroupedData", "nfGroupedData", "groupedData", "data.frame")
containing the following columns:
an ordered factor indicating the tree on which the measurement is made. The ordering is according to increasing maximum diameter.
a numeric vector giving the age of the tree (days since 1968/12/31)
a numeric vector of trunk circumferences (mm). This is probably “circumference at breast height”, a standard measurement in forestry.
This dataset was originally part of package
nlme, and that has
methods (including for
Draper, N. R. and Smith, H. (1998), Applied Regression Analysis (3rd ed), Wiley (exercise 24.N).
Pinheiro, J. C. and Bates, D. M. (2000) Mixed-effects Models in S and S-PLUS, Springer.
require(stats); require(graphics) coplot(circumference ~ age | Tree, data = Orange, show.given = FALSE) fm1 <- nls(circumference ~ SSlogis(age, Asym, xmid, scal), data = Orange, subset = Tree == 3) plot(circumference ~ age, data = Orange, subset = Tree == 3, xlab = "Tree age (days since 1968/12/31)", ylab = "Tree circumference (mm)", las = 1, main = "Orange tree data and fitted model (Tree 3 only)") age <- seq(0, 1600, length.out = 101) lines(age, predict(fm1, list(age = age)))