Orange
Growth of Orange Trees
The Orange
data frame has 35 rows and 3 columns of records of the growth of orange trees.
Usage
Orange
Format
An object of class c("nfnGroupedData", "nfGroupedData", "groupedData", "data.frame")
containing the following columns:
- Tree
-
an ordered factor indicating the tree on which the measurement is made. The ordering is according to increasing maximum diameter.
- age
-
a numeric vector giving the age of the tree (days since 1968/12/31)
- circumference
-
a numeric vector of trunk circumferences (mm). This is probably “circumference at breast height”, a standard measurement in forestry.
Details
This dataset was originally part of package nlme
, and that has methods (including for [
, as.data.frame
, plot
and print
) for its grouped-data classes.
Source
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.
Examples
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)))