如何使用GGPLOT geom_point()进行选择性标记

With this code:

这段代码:

library(ggplot2)
p <- ggplot(mtcars, aes(wt, mpg))
p + geom_point()
p + geom_point() + geom_text(aes(wt, mpg, label=row.names(mtcars)))
library(ggplot2)
p <-