带有填充颜色的密度图的ggplot直方图

Question

我有下面的直方图 ggplot

library(ggplot2)
set.seed(1)
df <- data.frame(PF = 10*rnorm(1000))
ggplot(df, aes(x = PF)) + 
    geom_histogram(aes(y =..density..),
                   breaks = seq(-50, 50, by = 10), 
                   colour = "black", 
                   fill = "white") +
stat_function(fun = dnorm, args = list(mean = mean(df$PF), sd = sd(df$PF)))

现在我想用一些颜色填充法线密度曲线。我在下面试过没有成功

stat_function(fun = dnorm, args = list(mean = mean(df$PF), sd = sd(df$PF)), fill = 'red', alpha = 0.50)

有什么方法可以在正常密度曲线下的区域应用填充颜色？

Answer 1

您可以使用 non-default geom（此处：geom_ribbon）调用 stat_function()，并使用 [=14= 访问 stat_function 生成的 y-value ] 像这样：


## ... + 
  stat_function(fun = dnorm,
                args = list(mean = mean(df$PF), sd = sd(df$PF)),              
                mapping = aes(x = PF, ymin = 0,
                              ymax = after_stat(y) ## see (1) 
                              ),
                geom = 'ribbon',
                alpha = .5, fill = 'blue'
                )

(1) 关于访问 计算变量 （统计）：https://ggplot2.tidyverse.org/reference/aes_eval.html

带有填充颜色的密度图的ggplot直方图

ggplot histogram with density plot that is filled with color

r

histogram

ggplot2