Try looking at subset()... I typically use this when I'm trying to isolate
specific cases from a data frame.

Also, Dalgaard's introductory R book has some great examples for parsing
data in the manner you're attempting.... you might want to look at that.

Mike
On Thu, Dec 2, 2010 at 2:08 PM, Diogenas <diogenas@gmail.com> wrote:

>
> Hello,
> I understand that question is probably stupid, but ...
>
> I have data (polity IV index)
> "country","year","democ","autoc","polity","polity2"
> "1","Afghanistan             ",1800,1,7,-6,-6
> "2","Afghanistan             ",1801,1,7,-6,-6
> "3","Afghanistan             ",1802,1,7,-6,-6
>
> I need to create new data sets which includes only cases after year 1995.
> I've tried this command:
> poli2<-poli[poli$year > 1994,] ,
>  however it generated this:
> Error in poli[poli$year > 1994, ] : incorrect number of dimensions.
> Any ideas how i can overcome this?
>
> Thank in advance for your help,
>
>
>
>
>
> -----
> Diogenas
> --
> View this message in context:
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>
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>



-- 
Michael Rennie, Research Scientist
Fisheries and Oceans Canada, Freshwater Institute
Winnipeg, Manitoba, CANADA

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