使用所选因子级别的值将水平线添加到ggplot-barchart

Question

在这个情节中

df <- data.frame(factor = as.factor(c(rep("A",3), rep("B",3))), Treatment = c(rep(c("A","B","C"),2)), values=runif(6,0,1))

ggplot(df, aes(Treatment, values))+
  geom_bar(stat="identity", position="dodge") +
  facet_wrap(~factor)

如何使用给定治疗级别的geom_hline（例如“A”）向每个方面添加yintercept

+geom_hline(data=df, aes(yintercept= df[df$Treatment=="A",]))

不起作用：

  

错误：美学必须是长度1或与数据（6）相同：   y截距

Answer 1

library(tidyverse)

df <- data.frame(factor = as.factor(c(rep("A",3), rep("B",3))), Treatment = c(rep(c("A","B","C"),2)), values=runif(6,0,1))

ggplot(df, aes(Treatment, values))+
  geom_bar(stat="identity", position="dodge") +
  facet_wrap(~factor) +
  geom_hline(data = df %>% filter(Treatment == "A"), aes(yintercept = values))

由reprex package（v0.2.0）创建于2018-03-23。