I support the idea of using -foreach- here, also
recommended by Thuy Le. But I would approach
the matter differently in detail.
First,
levelsof code, local(C)
or in Stata 8
levels code, local(C)
removes the need to type in all the names.
Second, why the repeated -use- and -drop-? You
could also do it this way:
use dataset
levelsof code, local(C)
foreach c of local C {
di "omitting `c':"
regress y x if code != "`c'"
}
If there are any problems with the -levelsof-/-levels-
approach, you can do this:
use dataset
egen CODE = group(code), label
su CODE, meanonly
forval i = 1/`r(max)' {
di "omitting `: label (CODE) `i''"
regress y x if code != `i'
}
See also
FAQ . . . . . . . . . . Making foreach go through all values of a variable
8/05 Is there a way to tell Stata to try all values of a
particular variable in a foreach statement without
specifying them?
http://www.stata.com/support/faqs/data/foreach.html
Nick
[email protected]
Neil Shephard
> Although in this example forval may be more appropriate...
>
> >> use dataset.dta, clear
> >> drop if code=="country1"
> >> regress y x
> >>
> >> use dataset.dta, clear
> >> drop if code=="country2"
> >> regress y x
> >
>
> Assuming that code is always countryN then you could...
>
> forval x = 1/N{
> use dataset, clear
> drop if(code == "country`x'")
> regress y x
> }
>
> You would substitute N in the above for the maximum country number.
>
> If however you actually have named countries such as "Australia",
> "United States", "Germany", "Nepal", "United Kingdom", "France" etc.
> then you would have to use foreach....
>
> foreach x in Australia "United States" France Germany "United
> Kingdom" Nepal{
> use dataset, clear
> drop if(code == "`x'")
> regress y x
> }
>
> Note that countries where there are two parts to the name need to be
> encapsulated in double quotes.
>
> Nick Cox has written a "Speaking Stata" article on this very topic...
>
> Cox, NJ (2002) Speaking Stata: How to face lists with fortitude. Stata
> Journal 2:202-222
>
> http://ideas.repec.org/a/tsj/stataj/v2y2002i2p202-222.html
>
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