如何从R中的分组列生成单个直方图

install.packages("ggplot2")
install.packages("dplyr")

library(ggplot2)
library(dplyr)

data <- data.frame(group = rep(c("A", "B", "C"), each = 100),
                   value = rnorm(300))

grouped_data <- data %>%
  group_by(group) %>%
  summarize(mean_value = mean(value),
            median_value = median(value))

ggplot(grouped_data, aes(x = group, y = mean_value, fill = group)) +
  geom_bar(stat = "identity") +
  labs(title = "Histogram of Grouped Data",
       x = "Group",
       y = "Mean Value")