pdf("caffeine1.pdf")

caffeine <- read.fwf("C:\\data\\caffeine.dat", width=c(1,5,8),
col.names=c("subject_c", "dose_c", "endtime"))

attach(caffeine)

dose_c <- factor(dose_c)
subject_c <- factor(subject_c)

caffeine1.rbd <- aov(endtime ~ subject_c + dose_c)

summary(caffeine1.rbd)

interaction.plot(subject_c,dose_c,endtime)

caffeine.res <- residuals(caffeine1.rbd)

hist(caffeine.res)

dev.off()