添加用于ggpubr统计测试比较的括号

library(ggplot2)
library(ggpubr)

# 创建一个数据集
data <- data.frame(
  group = rep(c("A", "B", "C"), each = 10),
  value = c(rnorm(10, mean = 5), rnorm(10, mean = 7), rnorm(10, mean = 9))
)

# 绘制箱线图
p <- ggboxplot(data, x = "group", y = "value",
               color = "group", palette = "jco",
               add = "jitter")

# 添加统计测试比较的括号
p <- add_comparison(p, group = c("A", "B"), 
                    test = "t.test", 
                    p.adjust.method = "holm")

p <- add_comparison(p, group = c("A", "C"), 
                    test = "t.test", 
                    p.adjust.method = "holm")

p <- add_comparison(p, group = c("B", "C"), 
                    test = "t.test", 
                    p.adjust.method = "holm")

# 显示图形
print(p)