Jenny Baxter
> >I am producing a set of histograms using, for example,
> >
> >histogram educ, discrete percent addlabel xlabel(1 2 3 9 ,
> valuelabel
> >noticks ) ...
> >
> >
> >This produces a histogram of my variable (education), showing the
> >percentage in each category.
> >
> >I have two seemingly minor problems
> >1 I want to be able to format the label at the top of the
> bar - currently
> >it mostly formats to 2 decimal points, but this isn't
> consistent, and I
> >really only want one decimal point. Can I do this?
There should be, perhaps, an option -mlabelformat()-
for this, but I can't see one, or a way of faking one.
Here is a work-around for -histogram-, illustrated on a
similar problem.
There is probably a much better work-around, but this works.
. sysuse auto, clear
. count if !mi(rep78)
. bysort rep78 : gen pc = 100 * _N / r(N)
. gen percent = string(pc, "%2.1f")
. twoway histogram rep78, discrete percent
xlabel(1 2 3 4 5 , valuelabel noticks)
|| scatter pc rep78, mlabel(percent) mlabpos(12)
ms(none) legend(off) ytitle(percent)
> >2 The education variable on the x-axis is plotted as if it
> is ordinal in
> >that it allows space on the axis for all values between 3
> and 9, even
> >though these are not even valid values of the variable. Do
> I have to
> >recode the variable, or is there another one to make the
> categories be
> >treated as nominal?
Rather, the educational variable on the x axis is treated
as interval (differences matter), and you want it treated as
ordinal (differences don't matter, but order does).
In a strong sense, this is what a histogram _is_: a plot
of a frequency distribution for a quantitative variable
in which the values of the variable are taken literally,
meaning numerically.
One alternative is to recode by a mapping to successive
integers. This is easier than -recode-:
. egen Educ = group(educ), label
. _crcslbl Educ educ
Another alternative is user-written -catplot- from
SSC. One advantage of that is that you don't need
any prior trickery: you can do it all in one command,
and your format problem is also directly soluble.
. ssc inst catplot
. catplot bar educ , percent bar(1, bstyle(histogram))
blabel(bar, format(%2.1f))
Nick
[email protected]
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