Sitka:
Growth Curves for Sitka Spruce Trees in 1988
Description
The Sitka
data frame has 395 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 five times in 1988, at roughly monthly intervals.
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, OxfordReferences
Venables, W. N. and Ripley, B. D. (2002)
Modern Applied Statistics with S. Fourth edition. Springer.