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

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