分组数据制作散点图

>library(ISwR)
>summary(hellung)
    glucose           conc           diameter
 Min.   :1.000   Min.   : 11000   Min.   :19.20
 1st Qu.:1.000   1st Qu.: 27500   1st Qu.:21.40
 Median :1.000   Median : 69000   Median :23.30
 Mean   :1.373   Mean   :164326   Mean   :23.00
 3rd Qu.:2.000   3rd Qu.:243000   3rd Qu.:24.35
 Max.   :2.000   Max.   :631000   Max.   :26.30
> plot(conc,diameter,pch=c(1,16)[factor(glucose)])
Error in plot(conc, diameter, pch = c(1, 16)[factor(glucose)]) :
  找不到对象'conc'
> attach(hellung)
> plot(conc,diameter,pch=c(1,16)[factor(glucose)])
> plot(conc,diameter,pch=c(1,16)[factor(glucose)],log="x")