Re: [R] Remove empty levels in subset

2012-06-26 Thread svo
Thank you very much. The advice I followed (and which, for some reason, I do
not see here right now) was to use 'droplevels'. I needed the command for
several variables at the same time, so this was very convenient.

>
Hello,

Have you tried 'droplevels':
test <-data.frame(a=as.factor(rep(c("f1","f2","f3"),10)),b=rep(c(1,2,3),10)) 
test2 <- subset(test,test$a=="f1") 
summary(test2)
  ab
 f1:10   Min.   :1  
 f2: 0   1st Qu.:1  
 f3: 0   Median :1  
 Mean   :1  
 3rd Qu.:1  
 Max.   :1  
test3<-droplevels(test2)
summary(test3)
  ab
 f1:10   Min.   :1  
 1st Qu.:1  
 Median :1  
 Mean   :1  
 3rd Qu.:1  
 Max.   :1  
A.K.
>

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Re: [R] Remove empty levels in subset

2012-06-26 Thread svo
Hi,

I have exactly the same question (how to remove empty levels in my subset),
but in my case the factor command does not work, because my dataframe is not
atomic

> Try this:
>
> test2$a <- factor(test2$a)
>

R gives me the error message:

Error in sort.list(y) : 'x' must be atomic for 'sort.list'
Have you called 'sort' on a list?

Do you have advice?

Thank you

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