Growth of Spruce Trees

Description

The Spruce data frame has 1027 rows and 4 columns.

Format

This data frame contains the following columns:

Tree

a factor giving a unique identifier for each tree.

days

a numeric vector giving the number of days since the beginning of the experiment.

logSize

a numeric vector giving the logarithm of an estimate of the volume of the tree trunk.

plot

a factor identifying the plot in which the tree was grown.

Details

Diggle, Liang, and Zeger (1994, Example 1.3, page 5) describe data on the growth of spruce trees that have been exposed to an ozone-rich atmosphere or to a normal atmosphere.

Source

Pinheiro, J. C. and Bates, D. M. (2000), Mixed-Effects Models in S and S-PLUS, Springer, New York. (Appendix A.28)

Diggle, Peter J., Liang, Kung-Yee and Zeger, Scott L. (1994), Analysis of longitudinal data, Oxford University Press, Oxford.

Examples

data(Spruce)