--- On Tue, 10/3/09, Tomas Lind wrote:
> I would like to see the value of Z for combinations of A
> and B (or for combinations of A, B and C). Missing should be
> regarded as a category.
You can use -tab- with the -bys- prefix and the -missing-
option, like in the example below. I also find it useful
in this kind of datapreparation tasks to include several
-assert- statements. Those -assert- have saved me a
couple of times. For more, see:
Gould, William (2003) "Stata tip 3: How to be assertive",
The Stata Journal, 3(4): 448.
http://www.stata-journal.com/article.html?article=dm0003
*--------------- begin example ---------------------
sysuse auto, clear
sum price , meanonly
gen expensive = price > r(mean) if price < .
bys expensive: tab rep78 foreign, missing
assert foreign == 0 if expensive == 0 & rep78 == 1
*----------------- end example ---------------------
(For more on how to use examples I sent to the Statalist, see
http://home.fsw.vu.nl/m.buis/stata/exampleFAQ.html )
Hope this helps,
Maarten
-----------------------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
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