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| From | Jacob-Jan Koopmans <jacob-jan.koopmans@student.uva.nl> |
| To | statalist@hsphsun2.harvard.edu |
| Subject | Re: st: RE: RE: Unexpected error from -merge- |
| Date | Mon, 23 Sep 2013 22:53:05 +0200 |
It indeed looks like -isid- is the way to go. Thanks a lot! Jacob On Mon, Sep 23, 2013 at 6:22 PM, Radwin, David <dradwin@rti.org> wrote: > Yes, and please consider using -isid-, which detects missing values as well as duplicate values. Occasionally this may save you from trouble. For example: > > . clear > > . set obs 100 > obs was 0, now 100 > > . gen cbhiind=_n in 1/99 > (1 missing value generated) > > . duplicates report cbhiind > > Duplicates in terms of cbhiind > > -------------------------------------- > copies | observations surplus > ----------+--------------------------- > 1 | 100 0 > -------------------------------------- > > . isid cbhiind > variable cbhiind should never be missing > r(459); > > David > -- > David Radwin > Senior Research Associate > Education Studies Division > RTI International > 2150 Shattuck Ave., Suite 800 > Berkeley, CA 94704 > Phone: 510-665-8274 > > www.rti.org > >> -----Original Message----- >> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner- >> statalist@hsphsun2.harvard.edu] On Behalf Of Joe Canner >> Sent: Monday, September 23, 2013 8:48 AM >> To: statalist@hsphsun2.harvard.edu >> Subject: st: RE: Unexpected error from -merge- >> >> By default when you do -duplicates report-, it is looking for duplicates >> with respect to every variable in your data set, which is why you have all >> unique records. What you want is -duplicates report actpsid- which will >> give you just the duplicates with respect to the variable you are trying >> to merge on. >> >> Regards, >> Joe Canner >> Johns Hopkins University School of Medicine >> >> -----Original Message----- >> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner- >> statalist@hsphsun2.harvard.edu] On Behalf Of Jacob-Jan Koopmans >> Sent: Monday, September 23, 2013 11:21 AM >> To: statalist@hsphsun2.harvard.edu >> Subject: st: Unexpected error from -merge- >> >> Dear list members, >> >> I am receiving an unexpected error when merging data. >> I am using stata 12. >> >> I am trying to merge data in the following way: >> "sort actpsid >> merge 1:m actpsid using "cbhiind" ". >> >> This, however, results in the following error: >> "variable actpsid(my individual identifier) does not uniquely identify >> observations in the master data r(459)." >> This would normally suggest(as far as I know), there are duplicates of >> actpsid in the master data. However, when checking for duplicates by >> using: duplicates report. I receive the following nice report: >> >> "Duplicates in terms of all variables >> -------------------------------------------------------- >> copies | observations surplus >> ----------+-------------------------------------------- >> 1 | 8772 0 >> --------------------------------------------------------" >> >> Therefore, I suppose the error is not resulting from duplicates in my >> identifier variable. >> >> I would thus like to ask whether there are other reasons why the above >> mentioned error appears. >> >> Kind regards, >> Jacob-Jan Koopmans > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/faqs/resources/statalist-faq/ > * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/