Plotting labels as points in R

Question

I have the following:

> x<-runif(20)
> y<-rnorm(x)
> g<-rep(factor(LETTERS[1:4]),5)

How can I do

> plot(x,y)

so that the points that are plotted is the corresponding value of g ?

Thanks!

Answer 1

Try

plot(x,y,type="n")
text(x,y,as.character(g))

or (obligatory ggplot)

library(ggplot2)
d <- data.frame(x,y,g)
qplot(x,y,label=g,geom="text",data=d)

or (lattice)

library(lattice)
xyplot(y~x,
    panel=function(...) { 
       panel.xyplot(...,type="n")
       panel.text(x,y,g) })

(I don't know how well that last solution would work if one actually wanted to use some of the features of lattice like dividing the plot into multiple panels ...)

Answer 2

对于单行解决方案，请使用pch （即“绘图字符”）参数：

plot(x,y,pch=as.character(g))