在ggplot2中将第二个分组添加到具有共享x轴的分组多面板条形图

library(ggplot2)

# 准备数据集
df <- data.frame(
  x = c(1, 2, 3, 1, 2, 3),
  y = c(10, 15, 8, 12, 6, 9),
  group = c("A", "A", "A", "B", "B", "B"),
  group2 = c("C", "C", "D", "D", "E", "E")
)

# 创建基础图形
p <- ggplot(df, aes(x = x, y = y, fill = group)) +
  geom_bar(stat = "identity", position = "dodge")

# 添加第二个分组
p <- p + facet_grid(. ~ group2)

# 自定义外观
p <- p + labs(title = "分组多面板条形图",
              x = "x轴",
              y = "y轴") +
  theme(plot.title = element_text(hjust = 0.5),
        axis.title = element_text(size = 12),
        axis.text = element_text(size = 10))

# 打印图形
print(p)