run <- rep(1:10,each=3)

pressure <- c(1,2,4,1,4,5,2,3,5,3,4,5,2,4,5,
              1,3,4,1,2,3,1,3,5,1,2,5,2,3,4)

y <- c(16,18,32,19,46,45,26,39,61,21,35,55,19,47,48,
       20,33,31,13,13,34,21,30,52,24,10,50,24,31,37)

pressure <- 175+75*pressure

methgluc <- data.frame(run,pressure,y)

attach(methgluc)

run <- factor(run)
pressure <- factor(pressure, ordered=T)

methgluc.mod1 <- aov(y ~ run + pressure)
summary(methgluc.mod1)
TukeyHSD(methgluc.mod1,"pressure")