如何从此代码生成的图例中删除字母"a"？如果我删除了geom_text,那么'a'字母将不会显示在图例中.不过我想保留geom_text.
ggplot(data = iris, aes(x = Sepal.Length, y=Sepal.Width, shape = Species, colour = Species)) +
geom_point() +
geom_text(aes(label = Species))