# This program reproduces a similar output of Fig 3.21 
# Page 129 in BCK 
# Created 060312 by C. Andy Tsao
# Load the package "foreign"
# Switch your working dir to the dir where your data is

t36<-read.S("t3-6 starting salary.splus")
t36[,1]
t36[,2]
dt36<-data.frame(gpa=t36[,1],salary=t36[,2])
dt36
attach(dt36)
plot(salary~gpa)
fm<-lm(salary~gpa)
abline(fm)
summary(fm)
par(mfrow=c(2,2));
plot(fm)
history()
# When you quit from R, do NOT save workspace image unless necessary.