Sitka89 {MASS}R Documentation

Growth Curves for Sitka Spruce Trees in 1989

Description

The Sitka89 data frame has 632 rows and 4 columns. It gives repeated measurements on the log-size of 79 Sitka spruce trees, 54 of which were grown in ozone-enriched chambers and 25 were controls. The size was measured eight times in 1989, at roughly monthly intervals.

Usage

Sitka89

Format

This data frame contains the following columns:

size
measured size (height times diameter squared) of tree, on log scale
Time
time of measurement in days since 1 January 1988
tree
number of tree
treat
either "ozone" for an ozone-enriched chamber or "control"

Source

P. J. Diggle, K.-Y. Liang and S. L. Zeger (1994) Analysis of Longitudinal Data. Clarendon Press, Oxford

See Also

Sitka


[Package MASS version 7.2-33 Index]