R中具有多个变量的条形图

library(ggplot2)

# 创建一个包含多个变量的数据框
data <- data.frame(
  category = c("A", "B", "C", "D"),
  variable1 = c(10, 15, 8, 12),
  variable2 = c(5, 9, 6, 10),
  variable3 = c(7, 11, 9, 13)
)

# 使用ggplot函数创建绘图对象，并指定数据源和变量映射
p <- ggplot(data, aes(x = category))

# 添加条形图层，并指定变量映射和填充颜色
p <- p + geom_bar(aes(y = variable1, fill = "Variable 1"), stat = "identity")
p <- p + geom_bar(aes(y = variable2, fill = "Variable 2"), stat = "identity")
p <- p + geom_bar(aes(y = variable3, fill = "Variable 3"), stat = "identity")

# 添加分面，将不同的变量绘制在不同的子图中
p <- p + facet_wrap(~ fill, scales = "free_y")

# 设置图形标题和坐标轴标签
p <- p + labs(title = "Multiple Variables Bar Chart", x = "Category", y = "Value")

# 显示图形
print(p)