如何在ggplot2中的条形图上同时显示计数和百分比？R

library(ggplot2)

# 创建一个示例数据集
data <- data.frame(
  category = c("A", "B", "C", "D"),
  count = c(10, 20, 30, 40)
)

# 计算每个类别的百分比
data$percentage <- round(data$count / sum(data$count) * 100, 2)

# 自定义函数，用于在条形图上显示计数和百分比
label_text <- function(x, y, z) {
  paste0(y, "\n(", z, "%)")
}

# 绘制条形图
ggplot(data, aes(x = category, y = count)) +
  geom_bar(stat = "identity") +
  geom_text(aes(label = label_text(count, count, percentage)), vjust = -0.5) +
  labs(title = "Bar Chart with Count and Percentage",
       x = "Category",
       y = "Count")