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From | Nick Cox <njcoxstata@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: Keep specific observation |
Date | Fri, 2 Sep 2011 15:17:07 +0100 |
bysort col1 (col2) : keep if col2 == _n & _N == 3 Nick On Fri, Sep 2, 2011 at 3:12 PM, Yun <yuniphone@yahoo.co.id> wrote: > I need help in stata command to drop/keep certain observations using stata 11.0 > > > There are two column of different data. Fisrt column is A,B,C (unique ID). The second column has data 1,2,3. > > Column 1 Column2 > A 1 > A 2 > A 3 > B 1 > B 2 > C 1 > C 2 > C 3 > D 1 > D 3 > > > I need all the observations that satisfy this condition --> column 1 will have group of column 2 (1,2,3)--> for instance A & C. > > I do not know the command for this. > * * 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/