Question

R语言 怎么把两个散点图画在一起

vd2=c(-16.3,-12.2,-8.2,-3.9,0,5.9,9.7,13.2,18.1)
vd1=c(-16.6,-12.5,-8.8,-4.2,0,6,9.8,15,18.2)
y=c(-16,-12,-8,-4,0,4,8,12,16)
plot(y~vd1)
plot(y~vd2,col="red")
怎么把这两个散点图画在一起啊？

Answer 1

可以先用plot函数建立坐标系，再在建好的坐标系里画图。
vd2=c(-16.3,-12.2,-8.2,-3.9,0,5.9,9.7,13.2,18.1)
vd1=c(-16.6,-12.5,-8.8,-4.2,0,6,9.8,15,18.2)
y=c(-16,-12,-8,-4,0,4,8,12,16)
plot(-20:20, -20:20, type = "n") #建立坐标系
points(vd1, y, col = "red")
points(vd2, y, col = "blue", cex = 1.5)
可以参考points函数的帮助文件。。

Answer 2

require(ggplot2)
vd = rbind(data.frame(v=vd1, y=y, t=as.factor(1)), data.frame(v=vd2, y=y, t=as.factor(0)))
ggplot(vd, aes(x=v, y=y)) + geom_point(aes(color=t))