[R] data.frame: how to extract parts

[(Ted Harding)]

On 17-Jan-09 02:57:13, Jörg Groß wrote:
> Hi,
> I have a problem with the R syntax.
> It's perhaps pretty simple, but I don't understand it ...
> 
> I can extract a column from a data.frame with the following code
> for example ...
> 
> b$row1[b$row1 == "male"]
> 
> so I see all male-entries.
> 
> But I cannot extract all lines of a data.frame depending on this  
> criterium;
> 
> only.male <- b[b$row1 == "male"]
> 
> With that, I get an "undefined columns selected" message.
> 
> So how can I extract lines of a data.frame depending on a level  
> variable?

  only.male <- b[b$row1 == "male",]

should work.
Ted.

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Date: 17-Jan-09                                       Time: 09:48:43
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