R语言 多项式回归 polynomial regression

R语言 多项式回归示例

rm(list=ls())
data <- swiss
data[,1:5] <- scale(data[,1:5])

data1 <- data
for (i in 1:3) {
  mdl <- lm(Examination ~ poly(Education, degree=i), data = data)
  data1[,6+i] <- predict(mdl,data)
}

# 作图
library(ggplot2)
ggplot(data1)+
  geom_point(aes(x=Education,y=Examination))+
  geom_line(data=data1, aes(x=Education,y=V7),color="red")+
  geom_line(data=data1, aes(x=Education,y=V8),color="blue")+
  geom_line(data=data1, aes(x=Education,y=V9),color="green")