ggplot:如何用箭头连接图表中的某些条形图

library(ggplot2)

# 创建一个数据框
data <- data.frame(
  category = c("A", "B", "C", "D"),
  value = c(10, 20, 15, 25)
)

# 创建一个基础图表
p <- ggplot(data, aes(x = category, y = value)) +
  geom_bar(stat = "identity")

# 添加箭头连接
p <- p +
  geom_segment(aes(x = "A", xend = "B", y = 10, yend = 20),
               arrow = arrow(length = unit(0.3, "cm"))) +
  geom_segment(aes(x = "C", xend = "D", y = 15, yend = 25),
               arrow = arrow(length = unit(0.3, "cm")))

# 添加箭头标签
p <- p +
  geom_text(aes(x = "B", y = 20, label = "Arrow 1"),
            vjust = -0.5, hjust = -0.5) +
  geom_text(aes(x = "D", y = 25, label = "Arrow 2"),
            vjust = -0.5, hjust = -0.5)

# 显示图表
print(p)