R: Growth of Loblolly pine trees

Loblolly {datasets} | R Documentation

## Growth of Loblolly pine trees

### Description

The `Loblolly` data frame has 84 rows and 3 columns of records of the growth of Loblolly pine trees.

### Usage

    Loblolly

### Format

An object of class `c("nfnGroupedData", "nfGroupedData", "groupedData", "data.frame")` containing the following columns:

height

  a numeric vector of tree heights (ft).

age

  a numeric vector of tree ages (yr).

Seed

  an ordered factor indicating the seed source for the tree. The ordering is according to increasing maximum height.

### 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

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.

### Examples

    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)
    age <- seq(0, 30, length.out = 101)
    lines(age, predict(fm1, list(age = age)))

[Package datasets version 3.1.2 Index]