sitka {SemiPar} | R Documentation |
The sitka
data frame contains measurements
of log-size for 79 Sitka spruce trees grown in normal
or ozone-enriched environments. Within each year, the
data are organised in four blocks, corresponding to
four controlled environment chambers. The first
two chambers, containing 27 trees each, have
an ozone-enriched atmosphere, the remaining two,
containing 12 and 13 trees respectively, have a normal
(control) atmosphere.
data(sitka)
This data frame contains the following columns:
Diggle, P.J., Heagerty, P., Liang, K.-Y. and Zeger, S.L. (2002). Analysis of Longitudinal Data, Second Edition, Oxord: Oxford University Press.
Ruppert, D., Wand, M.P. and Carroll, R.J. (2003)
Semiparametric Regression Cambridge University Press.
http://stat.tamu.edu/~carroll/semiregbook/
library(SemiPar) data(sitka) attach(sitka) library(lattice) ozone.char <- rep("control",nrow(sitka)) ozone.char[ozone==1] <- "ozone" xyplot(log.size~days|ozone.char,data=sitka,groups=id.num,type="b")