如何在ggplot中用两个不同的变量在一个条形图中绘制柱状图

library(ggplot2)

# 导入数据集
data <- data.frame(
  category = c("A", "B", "C", "D"),
  variable1 = c(10, 15, 8, 12),
  variable2 = c(5, 9, 6, 10)
)

# 创建基础图层并添加几何图层
plot <- ggplot(data, aes(x = category)) +
  geom_bar(aes(y = variable1, fill = "Variable 1"), stat = "identity") +
  geom_bar(aes(y = variable2, fill = "Variable 2"), stat = "identity", position = "dodge")

# 添加轴标签和标题
plot <- plot +
  xlab("Category") +
  ylab("Value") +
  ggtitle("Comparison of Variable 1 and Variable 2")

# 自定义图表
plot <- plot +
  theme(axis.text.x = element_text(angle = 45, hjust = 1))

# 显示图表
plot