Re: [R] Boxplot philosophy {was "Boxplot in R"}

From: Ted Harding <Ted.Harding_at_nessie.mcc.ac.uk>
Date: Tue 12 Jul 2005 - 18:43:46 EST


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)))

Best wishes,
Ted.



E-Mail: (Ted Harding) <Ted.Harding@nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 094 0861
Date: 12-Jul-05                                       Time: 09:42:48
------------------------------ 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 Received on Tue Jul 12 19:17:47 2005

This archive was generated by hypermail 2.1.8 : Fri 03 Mar 2006 - 03:33:31 EST