st: data transformation

[Seok-Woo Kwon <kwonsw@gmail.com>]

Dear all:

I do not know how to describe my problem in general terms. So let me
use an example to describe it. (I am using Stata 12 for Windows.)

I have about 10,000 observations and 1,000 variables on individuals,
but 4 observations and 3 variables will be enough to show the problem.
My data looks like this:

           id       X      Y    Z
          -----------------------
          001      1      2    X
          002      2      3    Y
          003      3      5    2
          004      4      6    Y
          -----------------------

I need data that looks like this:

           id       X      Y    Z     Z_transformed
          --------------------------------------------
          001       1    2    X                   1
          002       2    3    Y                   3
          003       3    5    2                   2
          004       4    6    Y                   6
          --------------------------------------------

That is, some values in the variable "Z" will be a variable name (like
"X" or "Y"). I would like to transform that variable into a value of
that variable for the observation.
For example, the value of Z for id 001 is X. Instead of X, I would
like to show the value of X for id oo1 (which is 1). Is there a way to
program this in Stata?

Thank you.

Seok-Woo Kwon
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