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From | Benedikt Achatz <benedikt.achatz@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | st: Adding up prior iterations of a variable in a time series dataset |
Date | Sun, 24 Jun 2012 16:41:47 +0200 |
Hello,I am a student and rather new to Stata, and i just can't figure out how this works. I have been browsing the web for some time and haven't found a solution that worked for me.
I have a dataset that contains observations of websites at different points in time. There is a variable, clicks, that contains the clicks in one time period. What I need to do now is to create a variable clicks_to_date that contains the clicks in every time period before the current one, including that one.
This is the code I have been using thus far, without much success... levelsof page_id, local(pg_id) levelsof time_var, local(tm_vr) cap drop clicks_to_date gen clicks_to_date = 0 local clicks_old = 0 foreach id in `pg_id'{ foreach x in `tm_vr'{ if `x' == 1 {local clicks_old = 0 } replace clicks_to_date = clicks+`clicks_old' display `clicks_old' local clicks_old = clicks_to_date } } Can anyone please hint me into a direction how this could be done? Thanks, Ben * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/