>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")