r - 如何在 R 中向图表添加自定义图例？

Question

我一直在pairs()为此工作，并且花了很长一段时间尝试添加图例或使用幻影符号来更改标题中物种的颜色以与点...任何见解将不胜感激!这是一个问题。

# original code
pairs(iris[1:4], 
  main = "Width and Length (cm) of Iris's Petals and Sepals: Setosa, Veriscolor, Virginica", 
  pch = 24, bg = c("mediumorchid4", "mediumpurple1", "lightpink1")[unclass(iris$Species)], 
  upper.panel=NULL, labels=c("Sepal Length","Sepal Width","Petal Length","Petal Width"), 
  font.labels=1, cex.labels=2)

Answer 1

这是一个更好的选择，以防万一(不是很好)接受的答案消失:

pairs(iris[1:4], 
  main = "Width and Length (cm) of Iris's Petals and Sepals: Setosa, Veriscolor, Virginica", 
  pch = 24, bg = c("mediumorchid4", "mediumpurple1", "lightpink1")[unclass(iris$Species)], 
  upper.panel=NULL, labels=c("Sepal Length","Sepal Width","Petal Length","Petal Width"), 
  font.labels=1, cex.labels=2)

legend(x = "topright",legend = levels(iris$Species),
        pch = 24,pt.bg = c("mediumorchid4", "mediumpurple1", "lightpink1"),
        inset = 0.1)

我没有像乔希建议的那样使用locator，而是只是为inset寻找了一个合适的设置。