Re: [R] Recode factors

From: Doran, Harold <HDoran_at_air.org>
Date: Thu, 27 Mar 2008 13:54:16 -0400


Perfect. My headache is gone. Thanks.

> -----Original Message-----
> From: Henrique Dallazuanna [mailto:wwwhsd_at_gmail.com]
> Sent: Thursday, March 27, 2008 12:50 PM
> To: Doran, Harold
> Cc: r-help_at_r-project.org
> Subject: Re: [R] Recode factors
>
> If I understand, you can try this:
>
> levels(x)[is.na(as.numeric(levels(x)))] <- 0
>
> On 27/03/2008, Doran, Harold <HDoran_at_air.org> wrote:
> > I know this comes up, but I didn't see my exact issue in
> the archives.
> > I have variables in a dataframe that need to be recoded.
> Here is what
> > I'm dealing with
> >
> > I have a factor called aa
> >
> > > class(aa)
> > [1] "factor"
> > > table(aa)
> > aa
> > * 0 1 2 3 A B C D L N T
> > 0 0 1908 725 2089 0 0 67 0 0 2 1 6
> >
> > I need to recode everything that is not a numeric value
> into a 0. So,
> > for example
> >
> > > mm <- ifelse(aa == 'B', 0, aa)
> > > table(mm)
> > mm
> > 0 3 4 5 11 12 13
> > 67 1908 725 2089 2 1 6
> >
> > The recoding works, but the values are no longer what they were
> > previously. For example, what was a '1' is now a '4' etc.
> Is there a
> > way to recode factors and also keep the values the same as
> they were before?
> > That is, a '1' would remain a '1' after the recode?
> >
> > After the recoding, I need to convert to a numeric
> variable. I can do
> > this as
> >
> > mm <- as.numeric(as.character(aa))
> >
> > Harold
> >
> >
> > > sessionInfo()
> > R version 2.6.2 (2008-02-08)
> > i386-pc-mingw32
> >
> > locale:
> > LC_COLLATE=English_United States.1252;LC_CTYPE=English_United
> > States.1252;LC_MONETARY=English_United
> > States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252
> >
> > attached base packages:
> > [1] stats graphics grDevices utils datasets
> methods base
> >
> >
> > other attached packages:
> > [1] gdata_2.4.0
> >
> > loaded via a namespace (and not attached):
> > [1] gtools_2.4.0
> > >
> >
> > ______________________________________________
> > R-help_at_r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
>
> --
> Henrique Dallazuanna
> Curitiba-Paraná-Brasil
> 25° 25' 40" S 49° 16' 22" O
>



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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Thu 27 Mar 2008 - 18:01:12 GMT

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