Re: st: RE: Quick Question on how to drop individual observations

["Michael Blasnik" <michael.blasnik@verizon.net>]

Your original query was ambiguous.  The solution is now simpler:

bysort hhold rd: drop if _n==1 & _n<_N

will drop the first observation if there are duplicates on hhold and rd.  If 
you only want to keep the last observation (in case there are triplets or 
more) then:

bysort hhold rd: keep if _n==_N

Michael Blasnik
michael.blasnik@verizon.net

----- Original Message ----- 
From: "JEFFREY ROSEN" <rosen.53@osu.edu>
To: <statalist@hsphsun2.harvard.edu>
Sent: Friday, June 16, 2006 12:44 PM
Subject: Re: st: RE: Quick Question on how to drop individual observations



> Thanks for the quick reply. Unfortunately, the code didn't work as I had 
> hoped.
>
> The dataset is drawn up as:
>
> obs 1 hhold 1 rd 1
> obs 2 hhold 1 rd 2
> obs 3 hhold 1 rd 2
> obs 4 hhold 1 rd 3
>
> The code below will drop the observation where the hhold value and the rd 
> value are the same. So in the above example, hhold = rd = 1 at observation 
> 1. Observation 1 was dropped. What I would like is to drop observation 2 
> because in observation 2, the identifiers are the same as observation 3.
>
> Thanks for your help,
>
> Jeff Rosen
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