X-ray pixel intensities over time
The Pixel data frame has 102 rows and 4 columns of data on the
pixel intensities of CT scans of dogs over time
This data frame contains the following columns:
a factor with levels 1 to 10 designating the dog
on which the scan was made
a factor with levels L and R designating the side
of the dog being scanned
a numeric vector giving the day post injection of the contrast on which the scan was made
a numeric vector of pixel intensities
Pinheiro, J. C. and Bates, D. M. (2000) Mixed-effects Models in S and S-PLUS, Springer.
fm1 <- lme(pixel ~ day + I(day^2), data = Pixel,
random = list(Dog = ~ day, Side = ~ 1))
summary(fm1)
VarCorr(fm1)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.