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Re: st: _byn1() and _byn2() variables in numlist


From   Stas Kolenikov <skolenik@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: _byn1() and _byn2() variables in numlist
Date   Mon, 27 Sep 2010 17:20:54 -0500

is this what you are trying to do?

program testing, byable(recall)
    marksample touse
    local last = _byn2()
    local first = _byn1()
    forvalues i=`last'(-1)`first' {
       di `i'
    }
end

_byn1() and _byn2() return you numbers, while -forvalues- needs a
string representation of a number. May be you can get along with
-forvalues `=_byn2()'(-1)`= _byn1()' { }- although that is somewhat
convoluted and difficult to read.

On Mon, Sep 27, 2010 at 4:39 PM, Poliquin, Christopher
<cpoliquin@hbs.edu> wrote:
> Hello,
>
> I am attempting to use the _by variables in a byable program, but am running into problems with syntax problems and invalid numlists that I cannot figure out how to resolve:
>
> I do...
>
> . program testing, byable(recall)
>  1.         marksample touse
>  2.         di _byn2()
>  3.         di _byn1()
>  4.         forvalues x = _byn2()(-1)_byn1() {
>  5.                 di `x'
>  6.         }
>  7. end
> . bys foo : testing
>
>
> And get ...
> ----------------------
> -> foo = 1
> 2
> 1
> invalid syntax
> r(198);
>
> And when using a numlist, i.e. foreach x of numlist _byn2()(-1)_byn1(), I get an invalid numlist error.
>
> How do I cycle through each observation number in a group within a byable program?


-- 
Stas Kolenikov, also found at http://stas.kolenikov.name
Small print: I use this email account for mailing lists only.

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