HW4 and 5 Problem 8

data

library('ISLR')

## Warning: package 'ISLR' was built under R version 3.5.2

library(splines)
mpg = Auto$mpg
accel = Auto$acceleration
cyl = Auto$cylinders
horse = Auto$horsepower
year = Auto$year
dis = Auto$displacement

x = displacement and y = mpg

y = mpg
x = dis
x0 = 250

poly2 = lm(y ~ poly(x, 2), data = Auto)
cubic = lm(y ~ bs(x, knots = c(105, 151, 275.8)), data = Auto)
natty = lm(y ~ ns(x, knots = c(105, 151, 275.8)), data = Auto)
smooth = smooth.spline(x, y, df = 10)

predict(poly2)[250-2]

##      250 
## 17.58407

predict(cubic)[250-2]

##      250 
## 17.63041

predict(natty)[250-2]

##      250 
## 17.67364

predict(smooth, 250)

## $x
## [1] 250
## 
## $y
## [1] 18.55003