The paper with pagination pp.99-88 was intended to be read
backwards, as the nuances are clearer in that way.
The rug fudge in this paper did what I wanted. I didn't
consider the problem of a legend as I never want to explain
a rug in a legend, but at most in a text caption (nothing
to do with Stata's -caption()-).
However, Neil has a very good reason for wanting a legend here.
My approach now with Stata 9 would be to start with -twoway spike-:
. sysuse auto
. gen y1 = 0
. gen y2 = -1
. twoway histogram mpg, freq || pcspike y1 mpg y2 mpg
. twoway histogram mpg, freq ||
pcspike y1 mpg y2 mpg if foreign, lcolor(red) ||
pcspike y1 mpg y2 mpg if !foreign, lcolor(blue)
which gives you a legend, although the spikes are horizontal
in the legend.
A clearer alternative might be a -onewayplot- (SSC).
This is not that much use to Neil, except insofar as it may add to the
incentive to upgrade from Stata 8.2.
His second problem would seem to need some -*size()- option to adjust
the marker label size.
Nick
[email protected]
Neil Shephard
>
> I'm attempting to draw a series of histograms each with two
> overlaid rugs underneath
> as described in Cox NJ (2004) The Stata Journal 4(1):99-88,
> and I have two problems
> which I would be grateful of assistance with.
>
> 1) As per the description in the SJ article, I'm using the
> '|' (pipe symbol) as marker
> labels, but because I am overlaying two rugs (see code
> below), I would like to have a
> legend which indicates what each refers to. However, because
> the -ms(none)- option is
> used to suppress the normal marker symbol, no marker symbol
> is shown in the legend
>
> A work around that I thought of was to use a very small
> marker symbol that would be
> masked by the '|' variable that is specified, and then use
> the symysize() and symxsize()
> legend contents options. This leaves the rugs as desired,
> and does result in the legend
> being defined, but the marker symbols are barely legible as
> the symysize() and
> symxszie() options seem to be ignored.
>
> Ideally I would like to include the '|' symbol in the legend,
> but can not find anything in the
> legend section of the manuals or help files on how to do this.
>
> 2) A minor problem, but when the histogram is drawn with the
> -freq- option the 'rugs'
> overlay the base of the histogram. This does not occur if
> the default -density- option is
> used (I've also checked this with the example used in the SJ
> and you see overlap in that
> data set when the -freq- options is specified on the histogram).
>
>
> Details of Stata version
> -------------------------------
>
> Version 8.2
> Born 10 Jan 2005
>
> Code (rather convoluted, and apologies for not devising a
> universal example)
> --------------------------------------------------------------
> ---------------------------------------
>
> histogram order if(dups == 1), by(region, title("Distribution
> of tagging and tagged SNPs"
> "in the CEPH (NW Europe ancestry) pop", size(medium))
> legend(symysize(*5)
> symxsize(*5) at(11) pos(0))) start(0) bin(500) freq
> plot(scatter where1 order if(dups == 1
> & tag_snp100k ~= ""), ms(none) mlabel(pipe) mlabpos(0) ||
> scatter where1 order if(dups
> == 1 & tag_snp100k == affy100k), ms(none) mlabel(pipe)
> mlabpos(0)) scheme(s1color)
>
> An example of the graph that I have managed to generate so
> far can be viewed at
>
> http://slack.ser.man.ac.uk/eg/eg.png
>
> I'd be very grateful if anyone can suggest any solution to
> either of the above problems.
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