Re: [Gretl-devel] factorized Boxplot
On Fri, 6 Oct 2017, Allin Cottrell wrote:
On Thu, 5 Oct 2017, Ignacio Diaz-Emparanza wrote:
> I just found this rare boxplot in the attachment. The help says that for
> each boxplot both whiskers should be of size 1.5 times the interquartile
> range, but I can see clearly that some of the lower whiskers are bigger
> than that ¿is it possible or is this a bug?
The doc is not entirely accurate: the "whiskers" are supposed tp extend to a
_maximum_ of 1.5 times the interquartile range (IQR), but never beyond the
range of the actual data. So the upper and lower whiskers may be of different
lengths.
That said, it would seem that, if the upper whiskers are correct in
Ignacios's plot then some of the lower whiskers are too long.
I'll look into it.
Having looked at our code my second reaction is, Let's see the data.
The definitions of the quartiles and the IQR can be questionable if
the sample sizes are very small and/or the data are discrete. At
this point I'm not convinced there's anything wrong with what we're
doing -- though admittedly there might be.
Allin