st: using value of one variable to read value of specific other variable out of a list of variables

[arne.weiss@uni-erfurt.de]

Dear everyone,

I am sure there is some obvious solution that I am not seeing, but I 
couldn't figure it out:
I want to create a variable (z) that contains the value from one 
variable out of a list of variables (say x1 - x3) depending on the 
valuable of another variable (y). The list of variables is a) named in a 
way that the value of y could be used to refer to the correct name of 
the variable and b) ordered so that the value of y could also be used a 
locational reference (as the offset command does in Excel). I don't 
think b) could work in STATA, but I couldn't find a solution for a) 
either. See below an example. Therein, z in the first row is supposed to 
be 1 and in the second row 5 (if y = 2, z is supposed to have the value 
of x2).

x1    x2    x3    y
1    2    3    1
0    5    4    2

Here is the closest I came towards a solution:  

local a = y
gen z = x`a'

This command, however, only does half the job as the value of the local 
a is not being rest for every row. I would be very happy for any advice.

Many thanks in advance!
Arne

--
Dr. Arne Robert Weiß
University of Erfurt 
Nordhäuser Str. 63, D-99089 Erfurt 
Tel: +49 361 737 4522
Fax: +49 361 737 4569
http://www.uni-erfurt.de/mikrooekonomie/lehrstuhlteam/dr-arne-weiss 
http://arneweiss.blogspot.com 

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