Loblolly {nls} | 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

data(Loblolly)

### Format

This data frame contains 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.

### Source

Kung, F. H. (1986),
“Fitting logistic growth curve with predetermined carrying
capacity”, *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

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)))