plot(trees)
str(trees)
trees.lm <- lm(Volume ~ Girth, data = trees)
summary(trees.lm)
coef(trees.lm)
plot(Volume ~ Girth,data = trees)
abline(coef(trees.lm))
residuals <- residuals(trees.lm)
hist(residuals)
plot(residuals)
abline(h=0)
str(anscombe)
anscombe3.lm <- lm(y3 ~ x3, data = anscombe)
plot(residuals(anscombe3.lm))
abline(h=0)
hist(residuals(anscombe3.lm))
qqnorm(residuals(anscombe3.lm))
qqline(residuals(anscombe3.lm))
qqline(residuals)
qqnorm(residuals(trees.lm))
qqline(residuals(trees.lm))
install.packages("HH")
library(HH)
plot(Volume ~ Girth,data = trees)
ci.plot(trees.lm)
trees.lm2 <- lm(Volume ~ Grith + Height,data = trees)
trees.lm2 <- lm(Volume ~ Girth + Height,data = trees)
summary(trees.lm2)
predict(trees.lm,newdata = data.frame(Girth = c(13,15)))
predict(trees.lm2,newdata = data.frame(Girth = c(13,15),Height=c(28,39)))
-57.9877 + 4.7082*13 + 0.3393*28