Davis <-
  read.table('http://math.uttyler.edu/nathan/classes/statistics/data/davis.data',header=TRUE)

attach(Davis)


plot(repwt,weight)
identify(repwt,weight)

Davis[12,]

detach(Davis)

Prostate <-
  read.table('http://math.uttyler.edu/nathan/classes/statistics/data/prostate.data',header=TRUE)

attach(Prostate)

mod <- lm(lpsa ~ lcavol + lweight + age + lbph + svi + lcp + gleason + pgg45)
summary(mod)
confint(mod)
confint(mod,level=.9)
confint(mod,level=.93)


nDavis <- Davis[-12,]
attach(nDavis)

plot(repwt,weight)
plot(repwt,weight,main='Going to get me in trouble?')
plot(repwt,weight,main='Going to get me in trouble?',type='n')
points(repwt[sex=='M'],weight[sex=='M'],col='blue')
points(repwt[sex=='F'],weight[sex=='F'],col='pink')

m1 <- lm(weight ~ repwt + sex)
summary(m1)

m2 <- lm(weight ~ repwt + sex + repwt*sex)
summary(m2)