Sitka89 | 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