Look at the help for -egen-, especially -egen, seq()-. 
Nick 
[email protected] 
kelly johnson
> I have created an observation variable X (e.g. gen X=_n) for 
> a large data 
> set. How can I create a new variable that is unique for successive 
> observations of 10 variables (i.e. i want this variable to be 
> equal to 1 in 
> obs 1-10, 2 in 11-20, and so forth)? There are way too many 
> obervations to write a simple -replace- command.
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/