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From | Nick Cox <n.j.cox@durham.ac.uk> |
To | "'statalist@hsphsun2.harvard.edu'" <statalist@hsphsun2.harvard.edu> |
Subject | st: RE: Creating repeated index |
Date | Wed, 20 Oct 2010 16:36:10 +0100 |
egen index = group(studentid visitdate) Nick n.j.cox@durham.ac.uk Pete I am trying to create an index/running number based upon same value of one variable, i.e., visit date. Different visit date will have different index/running number. I can do it by finding duplicates and drop them, then create an index and save as a new file, then merge a new file with the original one. However, I want to know whether there is a short cut to do this. My data will looks like this. StudentID Visit Date Item Index 1 1/1/2010 A 1 1 1/1/2010 B 1 1 2/4/2010 A 2 1 2/4/2010 B 2 1 2/4/2010 C 2 2 4/1/2010 A 1 2 4/1/2010 B 1 2 4/1/2010 C 1 2 3/3/2010 A 2 2 3/3/2010 E 2 * * 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/