Dear all, 
I just have a basic question. I have 20'000 observations, but a lot of different observation correspond to the same object (a lake) and hence, has the same ID. To do some commmand, I need that each observaiton have a unique identifier. So I need to give 20'000 different identifiers, one for each observation. 
So I neeed to create a new variable called obsID, which goes from 1 to 20'000, one for each observation. I can't copy paste my data and do it on Excel, because it would be to long. Can STATA Edit do that? 
Thanks,
Laura 
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