<>
See the tips by Nick and coauthor here: http://www.stata.com/support/faqs/data/distinct.html
For instance:
***
clear*
set obs 2000
gen id=_n
bys id: gen byte first =_n==1
cou if first
//now only 1999 unique
clear*
set obs 2000
gen id=_n
replace id=2 in 3
bys id: gen byte first =_n==1
cou if first
***
HTH
Martin
-------- Original-Nachricht --------
> Datum: Mon, 28 Dec 2009 12:05:41 -0600
> Von: "Weichle, Thomas" <[email protected]>
> An: [email protected]
> Betreff: st: Command to identify number of unique individuals
> Hi Statalisters,
> Is there a command that will list the number of unique individuals in my
> dataset? I'm familiar with the duplicates and dups commands, but these
> aren't showing me the number of unique individuals.
> It should be equivalent to the following SAS command which will identify
> the number of unique observations by study_id:
>
> PROC SORT NODUPKEY DATA=test;
> BY study_id;
> RUN;
>
> Tom Weichle
> Math Statistician
> Center for Management of Complex Chronic Care (CMC3)
> Hines VA Hospital, Bldg 1, C202
> 708-202-8387 ext. 24261
> [email protected]
>
> *
> * 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/
--
Preisknaller: GMX DSL Flatrate für nur 16,99 Euro/mtl.!
http://portal.gmx.net/de/go/dsl02
*
* 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/
