[R] subset

[Ngayee J Law]

I've found out that I have defined z elsewhere. If I remove z, the problem
is gone. Thanks!

- Jackie




                                                                                                                         
                    Uwe Ligges                                                                                           
                    <ligges at statistik.uni-do        To:     Ngayee J Law <Ngayee.Law at celeradiagnostics.com>              
                    rtmund.de>                      cc:     r-help at stat.math.ethz.ch                                     
                                                    Subject:     Re: [R] subset                                          
                    09/13/2002 01:56 AM                                                                                  
                                                                                                                         
                                                                                                                         




Ngayee J Law wrote:
>
> Dear list,
>
> I have a simple question. If I need to run linear regression on a subset
of
> the dataset, will
> the following two commands give the same output:
>
> lm(y ~ as.factor(x1) + as.factor(x2), data, subset = z==Z[1])
>
> and
>
> lm(y ~ as.factor(x1) + as.factor(x2), data[data$z==Z[1],] )
>
> I have got different results running the two commands. Am I missing
> something here, or it
> there a bug on the option subset?

Works for me on R-1.5.1, NT4.0.

Do you have z defined anywhere else?
If not and your version is recent: Can you provide an example?
Please, tell us your version of R and your OS as well.

Uwe Ligges




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