library(MASS)
library(ISLR)
lm.fit <- lm（medv~lstat,data=Boston)
attach(Boston)
lm.fit = lm(medv~lstat)
summary(lm.fit)
coef(lm.fit)
confint(lm.fit)
predict(lm.fit,data.frame(lstat=(c(5,10,15))),interval = “confidence”)
plot(lstat,medv)
abline(lm.fit)
abline(lm.fit,lwd=3,col=’red’)
plot(lstat,medv,col=”red”)
plot(lstat,medv,pch=20)
plot(lstat,medv,pch=”+”)
plot(1:20,1:20,pch=1:20)
par(mfrow=c(2,2))
plot(lm.fit)
plot(predict(lm.fit),residuals(lm.fit))
plot(predict(lm.fit),rstudent(lm.fit))