r - 向 geom_histogram 添加带有每个 bin 或列的百分比的标签

Question

我的问题是用组显示直方图列百分比(在 ggplot 中)。
我有两组，我绘制直方图
例子:

ggplot(data, aes(x = variable)) +
    geom_histogram(aes(group = grp, fill = grp, y=(..count../sum(..count..))), col = NA, alpha = 0.35) +
    stat_bin(aes(y=(..count../sum(..count..)), label=(..count../sum(..count..)), group=grp), geom="text",position=position_stack(vjust=0.5))

当我跑到上面时，我得到了总百分比 label=(..count../sum(..count..))但我想看到直方图列(箱)中的百分比，在任何箱中总和为 100%
例如:

Bin1: 20%;80%

Bin2:30%；70% 等等。

等等...

如果您想使用 mtcars，请查看以下示例代码:

ggplot(mtcars, aes(x = qsec)) +
  geom_histogram(aes(group = am, fill = am, y=(..count../sum(..count..))), col = NA, alpha = 0.35) +
  stat_bin(aes(y=(..count../sum(..count..)), label=(..count../sum(..count..)), group=am), geom="text",position=position_stack(vjust=0.5))

你有什么想法吗？

Answer 1

也许这就是你正在寻找的。我的方法使用辅助功能和一些 dplyr计算每个 bin 中每个组的比例:

library(ggplot2)
library(dplyr)

f <- function(x, count, group) {
  data.frame(x, count, group) %>%
    add_count(x, wt = count) %>%
    group_by(x, group) %>%
    mutate(prop = count / n) %>%
    pull(prop)
}

ggplot(mtcars, aes(x = qsec)) +
  geom_histogram(
    aes(
      group = factor(am), fill = factor(am),
      y = f(..x.., ..count.., ..group..)
    ),
    col = NA, alpha = 0.35, binwidth = 1
  ) +
  stat_bin(
    aes(
      y = f(..x.., ..count.., ..group..),
      label = scales::percent(f(..x.., ..count.., ..group..), accuracy = 1), group = am
    ),
    binwidth = 1, geom = "text", position = position_stack(vjust = 0.5)
  )