如何用r中的ggplot绘制多面直方图？

# 加载ggplot2包
library(ggplot2)

# 创建示例数据集
mydata <- data.frame(
  variable1 = rnorm(1000),
  variable2 = rnorm(1000),
  variable3 = rnorm(1000)
)

# 创建基本的绘图对象
p <- ggplot(data = mydata)

# 添加geom_histogram图层
p <- p + geom_histogram(aes(x = variable1), binwidth = 0.5, fill = "blue", alpha = 0.5)
p <- p + geom_histogram(aes(x = variable2), binwidth = 0.5, fill = "red", alpha = 0.5)
p <- p + geom_histogram(aes(x = variable3), binwidth = 0.5, fill = "green", alpha = 0.5)

# 添加标题和标签
p <- p + labs(title = "Multiple Histograms", x = "Values", y = "Frequency")

# 自定义外观
p <- p + theme(plot.title = element_text(size = 14, face = "bold"),
               axis.title = element_text(size = 12),
               axis.text = element_text(size = 10))

# 显示图形
print(p)