library("MASS")
data(faithful)
str(faithful)
dt <- faithful[c("eruptions","waiting")]
summary(dt)
with(dt,plot(eruptions ~ waiting))
with(dt,cor(eruptions,waiting))
with(dt,cor(eruptions,waiting)^2)

model <- lm(formula = eruptions ~ waiting, data = faithful)
summary(model)

boxplot(eruptions ~ waiting,data = dt, xlab="Waiting", ylab="Eruptions")

resid <- rstandard(model)
qqnorm(resid, ylab="Standardized Residuals",
       xlab="Normal Scores", main="Eruptions")
qqline(resid)

sisaan <- resid(model)
plot(dt$eruptions, sisaan, ylab="Residuals",
       xlab="Eruptions", main="Plot Sisaan")
abline(0,0)

nrow(faithful)
plot(1:272, sisaan, ylab="Residuals")