Hi Yuan,

It is not ellegant, but may work for you..


f<-as.factor(c("a","b","a"))

f.freq<-data.frame(table(f))
f.freq

lower.freq<-2
f.freq.subset<-subset(f.freq,f.freq$Freq>=lower.freq)
f.freq.subset

f.selected<-f[f %in% f.freq.subset$f]

f.selected<-factor(f.selected)
f.selected

Best wishes,

miltinho astronauta
brazil

On 8/29/08, Yuan Jian <jayuan2008@yahoo.com> wrote:
>
> Hi,
>
> how to remove levels that have less than a specific number such as 2. i.e..
>
> > f<-as.factor(c("a","b","a"))
> > f
> [1] a b a
> Levels: a b
>
> I want to remove level b because level b has less than 2.
> > f
> [1] a a
> Levels: a
>
>
>
>
>
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>
>
> ______________________________________________
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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.
>
>

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