st: Re: RE: Adding variables with common prefix

["R.E. De Hoyos" <redeho@hotmail.com>]

Thanks David and Maarten, both your solutions worked perfectly. 
Rafa

----- Original Message ----- 
From: "David Harrison" <david.harrison@icnarc.org>
To: <statalist@hsphsun2.harvard.edu>
Sent: Tuesday, May 30, 2006 1:21 PM
Subject: st: RE: Adding variables with common prefix



> You need:
>
> foreach v of varlist var* { 
> etc
>
> An alternative way would be to generate a new variable containing the
> sum of these variables, and look at the first observation of  the new
> variable. This is quicker to program, but presumably would be more
> computationally intensive.
>
> E.g.
>
> egen vsum = rsum(var*)
> scalar answer = vsum[1]
>
> David
>
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu
> [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of R.E. De Hoyos
> Sent: 30 May 2006 13:10
> To: statalist@hsphsun2.harvard.edu
> Subject: st: Adding variables with common prefix
>
>
> I have a large list of variables with a common prefix, say -var- (var1,
> var2, var3...). I want to generate a scalar with the sum of these
> variable's first observation. I tried the following loop, but for some
> reason that I can't see it is not working, it returns an invalid syntax
> error message:
>
> local sum = 0
> foreach v of var* {
>    local sum = `sum' + `v'[1]
> }
> scalar answer = `sum'
>
> What is wrong with this code? Is there an alternative way of adding up
> variables with a common prefix?
>
> Rafa
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