Re: st: Adding Reference Bars to Bar Graph

[Nick Cox <njcoxstata@gmail.com>]

The only way ahead given that you have taken this road is to add a
further category to the data (certainly not  a further variable).

The following may be suggestive of the main trick involved. I have
kept the example as simple as possible.

sysuse auto
preserve
expand 2 in L
replace foreign = 2 in L
* whatever constant you need
replace mpg = 42 in L
label def origin 2 "Total" , add
graph bar (mean) mpg, over(foreign)
restore

The problem with -catplot- here that it is based (in your case) on
-graph bar-, which does not behave like -twoway- in letting other
graphs be superimposed. So you must mess, at least temporarily, with
the data.

The alternative is to rewrite everything as a call to -twoway bar-,
but even in that case the easiest way may be to start with an
augmented dataset.

Nick

On Fri, Aug 17, 2012 at 5:33 AM, William Buchanan
<william@williambuchanan.net> wrote:

> I'm trying to automate production of a series of bar graphs that show the percentage of values and am having difficulty adding an extra bar with a constant value to the graph.  With the exception of this additional bar, I've managed to get something close to the current graphs being used with -catplot- (available from SSC; written by Nick Cox).  The syntax that I've used so far (with only slight modification) is:
>
> catplot schoolyr, over(skills) asyvar recast(bar) blabel(total, format(%2.0f)) percent(schoolyr) bar(1,color(green*.85) lc(black) lw(medthin)) bar(2, color(blue*.325) lc(black) lw(medthin)) ysc(r(0(10)100) lc(black)) ylab(0(10)100, angle(0) glc(black) tlw(vvthin) glw(vvthin)) yti(Percent) legend(label(1 "XXXXX Yr 2 (N=84)") label(2 "XXXXX Yr 3 (N=116)") pos(12) span region(lc(white))) ti("Survey Item Here", color(black)) b1title(" ") graphr(fc(white) color(white) ic(white))
>
>
> My goal is to get an additional bar added to the graph with  values showing the percentage of "overall".  In the actual dataset, the "overall" measure is a time-invariant constant and the firm wants to keep the same graphics formatting that they have already used.  I've tried messing around with the -over()- options and by adding the additional variable to the -varlist- in the command.  In each of these cases, there is a change to the x-axis (instead of showing an additional bar, the bars are disaggregated by the additional variable). I've provided syntax to generate something close to the data that I am working with.  The only difference between the syntax above and what I will eventually need to work with is the addition of an -if- statement that will be used to loop over the firms in the dataset.
>
> Thanks in advance for any assistance,
> Billy
>
>
> set obs 200
> set seed 10101
> g schoolyr=2 if _n<=84
> replace schoolyr=3 if schoolyr==.
> g sk=runiform()
> egen skills=cut(sk), group(4)
> sort skills
> g overall=1 if _n<=25
> replace overall=2 if _n<=50 & _n>=26
> replace overall=3 if _n<=75 & _n>=51
> replace overall=3 if _n>=76

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