st: AW: Reference column without knowing variable name?

["Martin Weiss" <martin.weiss1@gmx.de>]

<> 

Doubling every third _numeric_ var in this example. If you want strings in there, kill the -has(type numeric)- option...

*************
ma drop _all
sysuse auto, clear

qui ds, has(type numeric)
forv i=1(3)`=_N'{
	loc newvars `newvars' `:word `i' of `r(varlist)''
}

foreach var of local newvars{
	replace `var'=2*`var'
}
*************

Careful, everything rides on your order of variables here!

HTH
Martin


-----Ursprüngliche Nachricht-----
Von: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Andrew Wood
Gesendet: Dienstag, 2. März 2010 11:41
An: statalist@hsphsun2.harvard.edu
Betreff: st: Reference column without knowing variable name?

Hi everyone,

I am trying to create a STATA script that cycles through certain columns (variables) and perform a transformation. 

However, the datasets I am working with should only have every 3rd column (1,4,7,10...) transformed. This is ok but to make matters difficult, the datasets I am working with are VERY large and there is no pattern to the variable names.

I was wondering if anyone knew how to reference a column using a subscript in a loop, rather than a variable name (or use an integer to return the variable name of that column).

Thanks.

Andy

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