st: Ordering bar graphs by yvar value (was: Suggestions for SecondEdition of A Visual Guide to)

[David Radwin <radwin@berkeley.edu>]

Dear Nick,

Please accept my apologies for unintentionally slighting your program 
-catplot- as well as for taking so long to apologize. I do greatly 
appreciate your many, many helpful programs and explanations on this 
list and elsewhere.

It turns out the primary limitation I am running up against is not 
related to -catplot- per se but to Stata's graphing capabilities in 
general--or so I think. What I really would like to do is to create 
bar charts where the bars are ordered not by values of the xvar but 
by values of the yvar.

I think this example will make it more clear. Suppose for sake of 
illustration I want to compare the repair records of foreign and 
domestic cars. The commands

sysuse auto, clear
catplot hbar rep78, over(foreign) percent(foreign)

shows the bars in this order:

1. percentage of cars with foreign=0 and rep78=1
2. percentage of cars with foreign=0 and rep78=2
. . .
6. percentage of cars with foreign=1 and rep78=1 [this bar happens to 
have zero length]
. . .
10. percentage of cars with foreign=1 and rep78=5

That is all well and good, but I want to emphasize the difference 
between foreign and domestic on each value of rep78, with an ordering 
of

1. percentage of cars with foreign=0 and rep78=1
2. percentage of cars with foreign=1 and rep78=1
3. percentage of cars with foreign=0 and rep78=2
4. percentage of cars with foreign=1 and rep78=2
. . .
9. percentage of cars with foreign=0 and rep78=5
10. percentage of cars with foreign=1 and rep78=5

If there is a -graph- option that does this, I would be delighted to 
learn about it. The best I could muster was this workaround:

gen domestic=foreign==0
collapse (sum) foreign domestic, by(rep78)
foreach var of varlist foreign domestic {
	egen `var'_tot=total(`var')
	gen `var'_pct=round(100*`var'/`var'_tot , 1)
	}
graph hbar (asis) domestic_pct foreign_pct , over(rep78)

However, this solution is significantly more cumbersome and less 
flexible than using -catplot-. Can you or anyone else suggest a 
better alternative?

Thanks,

David

At 7:41 PM +0100 7/26/07, n j cox wrote:

> First, a reminder (to others in this and other threads as well)
> to say where user-written stuff you cite comes from. -catplot-,
> in this case, is a program on SSC.
>
> Second, what's the implication here? I looked at -catplot-
> and it allows the user a wildcard to relevant graph options,
> so you don't lose all control over detail.
>
> If you think the program is limited, please make a specific
> suggestion or criticism, so the author can think about it.
>
> The author happens to be me, so I endorse that general
> principle.
>
> Nick
> n.j.cox@durham.ac.uk
>
> David Radwin
>
> ...
> I would like more examples analogous to -catplot- but
> with greater control over formatting.
> ....
--
David Radwin, Principal Analyst // radwin@berkeley.edu
Office of Student Research, University of California, Berkeley
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