Message-ID: <Pine.LNX.4.44.0305111417430.6318-100000@gannet.stats>
Date: 2003-05-11T13:26:53Z
From: Brian Ripley
Subject: what does boxplot draw?
In-Reply-To: <3710.030511@eimb.ru>
?boxplot says
stats: a matrix, each column contains the extreme of the lower
whisker, the lower hinge, the median, the upper hinge and the
extreme of the upper whisker for one group/plot.
and that's accurate: please prefer the primary documentation to notes you
pick up somewhere on the Web.
For the definition of `hinge' see ?boxplot.stats and the references
therein. (The box goes from the lower hinge to the upper hinge.)
On Sun, 11 May 2003, Wladimir Eremeev wrote:
> Unfortunately I cannot find in the documentation what determines
> ranges of a 'box' in the box-and-whisker plot.
It's right there on the help pages for boxplot, bxp and boxplot.stats,
with references to the primary published literature.
> It is said in "Simple R" (http://www.math.csi.cuny.edu/Statistics/R/simpleR)
> that they are 1st and 3rd Qus usually.
>
> I tried to add to boxplot lines with (quantile(x,probs=0.25)), but
> lines do not coincide with edges of boxes.
[...]
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595