On 12-Jul-05 Ted Harding wrote: > On 12-Jul-05 Spencer Graves wrote: >> I'll bite: How does one detect bimodalidty from a boxplot? >> >> spencer graves >> >> Berton Gunter wrote: >> [...] >>> Finally, a tidbit for boxplot afficianados: how does one detect >>> bimodality from a boxplot? >>> >>> -- Bert Gunter > > Not definitively detectable of course, but certainly suspectable. > > Hint: What is the relationship between the distances from the "median" > line to the extremes of the "box", and from the extremes of the "box" > to the ends of the "whiskers", in the case of a uniform distribution? > > > > If that doesn't trigger it, then: > > Hint: > > unimod<-rnorm(1000,0,sqrt(26)) > nomod<-sqrt(12*26)*runif(1000) > boxplot(data.frame(cbind(unimod,nomod,bimod)))
OOPS!! (cut-&-pasted the wrong lines): unimod<-rnorm(1000,0,sqrt(26)) nomod<-sqrt(12*26)*(runif(1000)-0.5) bimod<-c(rnorm(500,-5,1),rnorm(500,5,1)) boxplot(data.frame(cbind(unimod,nomod,bimod))) > Best wishes, > Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <[EMAIL PROTECTED]> Fax-to-email: +44 (0)870 094 0861 Date: 12-Jul-05 Time: 10:24:34 ------------------------------ XFMail ------------------------------ ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
