绘图选项“bg”不起作用

Question

我这里有一段非常基本的 R 代码，以及它生成的绘图。为什么这个点没有用红色填充？

plot(1, 1, col="blue", bg="red", cex=4)

Answer 1

You need to use one of pch = 21 through 25 for bg to work

plot(1, 1, col = "blue", pch = 21, bg = "red", cex = 4)

From the points help file:

bg

background (fill) color for the open plot symbols given by pch = 21:25.