多个几何图形的ggplot2 z顺序(背景到前景)

library(ggplot2)

# 创建一个数据框
data <- data.frame(
  x = c(1, 2, 3),
  y = c(1, 2, 3)
)

# 创建一个基础图形对象
base_plot <- ggplot(data, aes(x, y))

# 添加背景图形
base_plot <- base_plot + geom_point(aes(color = "Background"), size = 5)

# 添加前景图形
base_plot <- base_plot + geom_point(aes(color = "Foreground"), size = 3)

# 调整z顺序，将背景图形绘制在前景图形之后
base_plot <- base_plot + geom_point(aes(color = "Background"), size = 5, order = 1)

# 显示图形
print(base_plot)