# st: AW: generating variables conditional on others (again..)

 From "Martin Weiss" To Subject st: AW: generating variables conditional on others (again..) Date Thu, 30 Apr 2009 15:33:35 +0200

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Look at

*************
help tsvarlist
*************

The operator "F." gives you the one period forward value.

HTH
Martin

-----Ursprüngliche Nachricht-----
Von: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Linn Renée
Naper
Gesendet: Donnerstag, 30. April 2009 15:26
An: statalist@hsphsun2.harvard.edu
Betreff: st: generating variables conditional on others (again..)

I would like to do something like this:

forvalue m=1/12 {
replace X3 = X2 in [X1==`m' + 1]
}

This is not possible, but I think it illustrates my problem as I need to
tell stata to replace a variable (X3) with values (X2) from other
observations identified by a third variable (X1).

I have a sample with a date-identifier, variable X1 giving the current month
and a variable X2 giving the mean price level for the same month. Thus,
within the same month the variable is constant. Data have several years.

Now I need a variable X3 which gives me the mean price level (X2) for the
coming month (actually I will generate several variable for the price level
for all months to come, but I guess the logic will be the same here).

Thus, I need to generate a variable X3 (g X3=.) and then replace it with the
values from X2 given in other observations. For month 1 (X1=1, January) X3
should contain the values of X2 when X1==2 (February) and so on.

I know I posted a similar problem I while ago, but the structure of the data
here is not the same, so I'm stuck again :(

Linn

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```