Re: st: panel data, sorting in deciles

[Maarten buis <maartenbuis@yahoo.co.uk>]

--- On Sun, 10/10/10, Biljana Dlab wrote:
> . foreach X of varlist dat* {
>   2. xtile deciles=`X', n(10)
>   3. }
> deciles already defined
> 
> why did I get "deciles already defined" message in red.

-xtile deciles- creates a new variable called deciles.
However, because you are doing this inside a loop, you 
are trying to do this multiple times. Lets say there are
3 dat* variables dat1, dat2, and dat3. In that case 
your loop tries to do the following:

step 1) For dat1 create a variable deciles containing the
        deciles of dat1
step 2) For dat2 create a variable deciles containing the
        deciles of dat2
step 3) For dat3 create a variable deciles containing the
        deciles of dat3

At step 2) -xtile- tries to create the variable deciles, 
but that variable was already created in step 2, so Stata 
complains and quits the loop.

In order to make such a loop work you need to make sure
that at each step it creates a variable with a different
name. One way of doing that is as follows (I don't like
capital letters in my code, it means more typing and more
chance of a typo/bug, but that is my personal preference):

foreach x of varlist dat* {
    xtile d_`x'=`x', n(10)
}

Hope this helps,
Maarten

--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany

http://www.maartenbuis.nl
--------------------------


      

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