如何使用ggplot2在双因素面的特定图上添加不同的垂直线？

2 回答

• 2

  答案在帮助文件 ?geom_hline() 中给出

  那里的例子是：

  # To show different lines in different facets, use aesthetics
  p <- ggplot(mtcars, aes(mpg, wt)) +
    geom_point() +
    facet_wrap(~ cyl)
  
  mean_wt <- data.frame(cyl = c(4, 6, 8), wt = c(2.28, 3.11, 4.00))
  p + geom_hline(aes(yintercept = wt), mean_wt)
  

  所以对于你的例子，这可能是：

  # create new dataframe
  intercept <- data.frame(vs=c(rep(0, 2), rep(1, 2), rep(0,3), rep(1,3)), 
                          am = c(rep(0, 4), rep(1, 6)), 
                          int = c(10, 20, 10, 20, 15, 25, 35, 15, 25, 35))
  # add vline to plot
  p + geom_vline(aes(xintercept=int), intercept)
  

  

  回复于 2024-05-03T09:42:14+08:00
• 2

  我发现最简单的方法是在单独的data.frame中定义行：

  line.df <- data.frame( am = rep(levels(as.factor(mtcars$am)),3) ,am.int = c(10,15,20,25,NA,35) )
  line.df <- line.df[!is.na(line.df$am.int),]
  
  library(ggplot2)
  p <- ggplot(mtcars, aes(mpg, wt)) + geom_point() + facet_wrap(vs ~ am)
  p + geom_vline(aes(xintercept = am.int), data = line.df)
  

  

  回复于 2024-05-03T09:42:14+08:00