Tagging in what sense?
How do you tell which soldiers are out of step?
Majority vote? How do you split a 50:50
agreement? Three variables say "Stata" and three
say "SAS"? (No, that's an easy one to identify
which are incorrect.)
(You didn't mention strings; I guess you don't
care about strings.)
One way forward is to note that the row maximum
and the minimum will be different if any values
differ. See -egen, rowmin()- or -egen, rowmax()-.
Another is that the row median will identify
a majority in all cases where it exists. See
-egenmore- for a row median function. See
http://www.stata.com/support/faqs/stat/medians.html
for a fuller story.
In the case where a median is the midpoint between
two values, then contrariwise, all values disagree
with it. You might still have a plurality somewhere.
All these functions ignore missings in the way
you want.
Yet another story is to -reshape-. Then see also
http://www.stata.com/support/faqs/data/distinct.html
http://www.stata.com/support/faqs/data/diff.html
Nick
[email protected]
Friedrich Huebler
> I would like to compare a set of variables and tag those that do not
> contain the same values. Missing values should be ignored. -egen
> newvar = diff(varlist)- is not an option because it does not skip
> missing values. The last command in the example below works but it
> becomes impractical with a longer list of variables.
>
> . sysuse auto
> . gen mpg2 = mpg if foreign==0
> . gen mpg3 = mpg if foreign==1
> . replace mpg3 = mpg+1 if rep78==2
> . egen tag = diff(mpg mpg2 mpg3)
> . gen tag2 = (mpg!=mpg2 & mpg<. & mpg2<. | mpg!=mpg3 & mpg<. & mpg3<.
> | mpg2!=mpg3 & mpg2<. & mpg3<.)
>
> The -egen- command tags all observations, the -gen- command only those
> that I expect to be tagged. Are there better solutions that can also
> be used with ten or more variables?
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