st: twoway by_option subtitle formatting

[Roger Harbord <roger.harbord@bristol.ac.uk>]

How can I persuade -graph twoway-'s -by- option to respect the formatting of 
the by-variable?

An example :

. sysuse auto
(1978 Automobile Data)

. describe gear_ratio

             storage  display     value
variable name   type   format      label      variable label
------------------------------------------------------------
gear_ratio      float  %6.2f                  Gear Ratio

. twoway scatter price mpg if gear_ratio <2.5, by(gear_ratio )

The first subgraph's subtitle is not "2.19" as i'd expect but 
"2.190000057220459". The fact that gear_ratio has format %6.2f is being 
ignored. One work-around is to convert it to a string:

. gen gear_ratio_str = string(gear_ratio, "%6.2f")
. twoway scatter price mpg if gear_ratio <2.6, by(gear_ratio_str )

However in general the stringed version of a number will have a different sort 
order so the ordering of the subgraphs may not be what i want - doesn't affect 
this example but does in my real application. The only solution I can think of 
is to label each value with its value - considerable extra hassle. Is there a 
simpler way?

(I'm using Stata 8.2 for Windows, updated to 27 Jul 2004.)

Thanks,
Roger.
----------------------------------------------------
Roger Harbord     mailto:roger.harbord@bristol.ac.uk
Department of Social Medicine, University of Bristol

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