r - 如何在R中的ggplot中将图例添加到geom_smooth

Question

在ggplot中将图例添加到其他平滑图时遇到问题。

    library(splines)
    library(ggplot2)
    temp <- data.frame(x = rnorm(200, 20, 15), y = rnorm(200, 30, 8))

    ggplot(data = temp, aes(x, y)) + geom_point() + 
      geom_smooth(method = 'lm', formula = y ~ bs(x, df=5, intercept = T), col='blue') + 
      geom_smooth(method = 'lm', formula = y ~ ns(x, df=2, intercept = T), col='red')

我有两个样条线：红色和蓝色。如何为他们添加图例？

Answer 1

将颜色放入aes()并添加scale_colour_manual()：

ggplot(data = temp, aes(x, y)) + geom_point() + 
  geom_smooth(method = 'lm', formula = y ~ bs(x, df=5, intercept = T), aes(colour="A")) + 
  geom_smooth(method = 'lm', formula = y ~ ns(x, df=2, intercept = T), aes(colour="B")) +
  scale_colour_manual(name="legend", values=c("blue", "red"))