如何控制显示哪些facet_wrap标签

# 安装并加载 ggplot2 包
if (!require("ggplot2")) install.packages("ggplot2")
library(ggplot2)

# 创建示例数据框
df <- data.frame(
  x = rnorm(100),
  y = rnorm(100),
  category1 = rep(c("A", "B", "C"), each = 33),
  category2 = rep(c("X", "Y", "Z"), times = 33)
)

# 使用 facet_wrap 创建子图
ggplot(df, aes(x = x, y = y)) +
  geom_point() +
  facet_wrap(~ category1 + category2, ncol = 3)

# 自定义标签函数
custom_labeller <- function(variable, value) {
  if (variable == "category1") {
    value[value %in% c("A", "B")] <- value[value %in% c("A", "B")]
    value[value %in% c("C")] <- ""
  }
  if (variable == "category2") {
    value[value %in% c("X", "Y")] <- value[value %in% c("X", "Y")]
    value[value %in% c("Z")] <- ""
  }
  return(value)
}

# 使用自定义标签函数
ggplot(df, aes(x = x, y = y)) +
  geom_point() +
  facet_wrap(~ category1 + category2, ncol = 3, labeller = custom_labeller)

custom_labeller <- function(variable, value) {
  print(paste("Variable:", variable))
  print(value)
  if (variable == "category1") {
    value[value %in% c("A", "B")] <- value[value %in% c("A", "B")]
    value[value %in% c("C")] <- ""
  }
  if (variable == "category2") {
    value[value %in% c("X", "Y")] <- value[value %in% c("X", "Y")]
    value[value %in% c("Z")] <- ""
  }
  return(value)
}