Here is one way of doing it:

> moreThan <- ave(choose$code, choose$code, FUN=length)
> moreThan
 [1] 2 2 4 4 4 4 2 2 6 6 6 6 6 6
> choose[moreThan > 2,]
   firm year code
3     2 2000   11
4     2 2001   11
5     2 2002   11
6     2 2003   11
9     4 2001   13
10    4 2002   13
11    4 2003   13
12    4 2004   13
13    4 2005   13
14    4 2006   13
>


On Sun, May 24, 2009 at 1:46 PM, Cecilia Carmo <cecilia.carmo@ua.pt> wrote:

> Hi R helpers!
>
> I have the following dataframe «choose»
> choose<-data.frame(firm=c(1,1,2,2,2,2,3,3,4,4,4,4,4,4),
> year=c(2000,2001,2000,2001,2002,2003,2000,2003,2001,2002,2003,2004,2005,2006),code=c(10,10,11,11,11,11,12,12,13,13,13,13,13,13))
> choose
>
> I want to subset it to obtain another one with those observations for which
> there more than 2 observations in the column «code». So I want a dataframe
> «chosen» like this:
>
> chosen<-data.frame(firm=c(2,2,2,2,4,4,4,4,4,4),year=c(2000,2001,2002,2003,2001,2002,2003,2004,2005,2006),code=c(11,11,11,11,13,13,13,13,13,13))
> chosen
>
> I’ve tried split() and then nrow() but I got nothing.
>
> Could anyone help me with this?
>
> Thanks
> Cecília (Universidade de Aveiro – Portugal)
>
> ______________________________________________
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

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