How to add an overall box plot to an "over" box plot?

[Karin Jensen]

Hi Statalisters

I am running the following type of command:
graph box outcome, over(group)

I have 12 different values within group, and so 12 boxplots appear on the graph.

I would like to add a 13th boxplot, labelled "all", which contains a boxplot of all observations of outcome.

How would l do this?

Thankyou

Karin

[Nick Cox]

This kind of problem is discussed at length in in the current Stata Journal. See http://www.stata-journal.com/article...article=gr0058 If you don't have access to a subscribed copy, or are too poor or mean to spend USD 8.75 on an excellent little article, the gist of the idea is accessible at http://www.stata.com/statalist/archi.../msg01102.html

(This paper is also relevant and accessible to all. http://www.stata-journal.com/sjpdf.h...iclenum=gr0045)

Here is some code any way. It's kind of kick yourself; it was obvious all along.

 
sysuse auto, clear
set scheme s1color 
preserve
local N = _N
expand 2
gen byte new = _n > `N'
replace rep78 = 6 if new
label def rep78 6 "all"
label val rep78 rep78

graph hbox mpg, over(rep78) nofill ytitle("MPG, by Repair Record")

[Karin Jensen]

As you say "Do'h!" - it's obvious now, though I would never have thought of it myself. Many thanks!

[Nick Cox]

Otherwise known as Simpsons' paradox [sic].