# Diagnostics for the final model fitted in Chapter 5, using R

library(lattice)
trellis.device(color=F)

# Generate Figure 5.3

qqnorm(model5.2.fit, ~resid(.))

# Generate Figure 5.4
 
fit <- predict(model5.2.fit)
res <- resid(model5.2.fit)
plotres.fit <- data.frame(rat.brain, fit, res)
xyplot(res ~ fit, data=plotres.fit, groups=treatment, xlab="Predicted value (+ = Carbachol, o = Basal)", ylab="Residual", abline=0)