Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
From | Nick Cox <n.j.cox@durham.ac.uk> |
To | "'statalist@hsphsun2.harvard.edu'" <statalist@hsphsun2.harvard.edu> |
Subject | RE: st: Extracting substrings from variable and combining variables. |
Date | Fri, 1 Jun 2012 18:31:55 +0100 |
There is a tutorial on -foreach- at SJ-2-2 pr0005 . . . . . . Speaking Stata: How to face lists with fortitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox Q2/02 SJ 2(2):202--222 (no commands) demonstrates the usefulness of for, foreach, forvalues, and local macros for interactive (non programming) tasks . search foreach will get you to a clickable link. If you want a composite variable, you can use -egen- and then modify the resulting variable with -replace- to get what you want. Or you can write your own code to get what you want. I don't know exactly what you want, so that rules out further suggestions from me for the time being. You would get better help by giving examples of what the variables you want would look like. Nick n.j.cox@durham.ac.uk Amal Khanolkar Thanks for the input and code: I didn't really understand what the code does (''for each etc...'') But it does pluck out the those that have the 3 diagnoses of interest and creates 3 separate variables as follows: tab has637 has637 | Freq. Percent Cum. ------------+----------------------------------- 0 | 2,969,464 99.26 99.26 1 | 21,992 0.74 100.00 ------------+----------------------------------- Total | 2,991,456 100.00 . tab has642 has642 | Freq. Percent Cum. ------------+----------------------------------- 0 | 2,948,590 98.57 98.57 1 | 42,866 1.43 100.00 ------------+----------------------------------- Total | 2,991,456 100.00 . tab hasO1 hasO1 | Freq. Percent Cum. ------------+----------------------------------- 0 | 2,968,084 99.22 99.22 1 | 23,372 0.78 100.00 ------------+----------------------------------- Total | 2,991,456 100.00 - The above also gives a lower number and skips those recorded as duplicates. - I think using the replace command to restructure preght is probably easier: however you meant I do it before that is using the original 12 variables and skipping egen all together? * * 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/