# R programs for Ex. 1, by Yu-Ling Tseng

# Which program should we use to analyze the data in EX. 1?
# Is one of the three models considered here correct $\ldots$ ?
table1 <- read.table("table1_data.txt", header=T);
table1
table1$Machine <- factor(table1$Machine)
table1$Replication <- factor(table1$Replication)
table1$Order <- factor(table1$Order)
attach(table1)
plot(Order, Time, xlab="Order");
windows();
plot(Replication, Time, xlab="Replication");
windows();
plot(Machine, Time, xlab="Machine");

fm <- aov(Time~Replication+Machine+Order, data=table1);
fm
summary(fm)

fm0 <- update(fm, .~.-Order)
summary(fm0);

fm1 <- update(fm0, .~.-Replication)
summary(fm1);


anova(fm,fm0,fm1);
coef(fm);
coef(fm0);
coef(fm1);