如何將圖例添加到ggplot中的geom_smooth中R

Question

將圖例添加到ggplot中的不同平滑有問題。

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') 

我有兩個樣條線：紅色和藍色。我如何爲他們添加圖例？

Answer 1

把顏色aes()並添加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"))