lme4 (version 0.6-11)

Pixel: X-ray pixel intensities over time

Description

The Pixel data frame has 102 rows and 4 columns of data on the pixel intensities of CT scans of dogs over time

source

Pinheiro, J. C. and Bates, D. M. (2000) Mixed-effects Models in S and S-PLUS, Springer.

Examples

data(Pixel)
Pixel$DS = getGroups(Pixel, ~ 1 | Dog/Side, level = 2)
fm1 <- lme(pixel ~ day + I(day^2), data = Pixel,
           random = list(DS = ~ 1, Dog = ~ 1))
summary(fm1)
VarCorr(fm1)