将上边/下边、中点和中点的线条添加到ggplot boxplot

library(ggplot2)

# 创建示例数据
set.seed(123)
data <- data.frame(
  x = rep(c("A", "B", "C"), each = 50),
  y = c(rnorm(50), rnorm(50, mean = 2), rnorm(50, mean = -2))
)

# 绘制箱线图并添加上边线、下边线和中点
ggplot(data, aes(x = x, y = y)) +
  geom_boxplot() +
  geom_segment(aes(x = x, y = upper, xend = x, yend = max, linetype = "Upper Line"), color = "red") +
  geom_segment(aes(x = x, y = lower, xend = x, yend = min, linetype = "Lower Line"), color = "blue") +
  geom_point(aes(x = x, y = middle, shape = "Middle Point"), color = "green") +
  scale_shape_manual(values = 16) +  # 设置点的样式为实心圆
  scale_linetype_manual(values = "solid")  # 设置线的样式为实线