[R] Remove levels

[Uwe Ligges]

Marc Bernard wrote:

> Daer All,
>  
> I have a factor  variable, X with 5 levels. When I type tables(X) it gives me:
>  
> table(X)
> 1     2   3    4   5 
> 10   5    0   0   0
>  
> How to drop the levels with zeros such that when I will type:
> table(X) it will give me:
>  
> table(X)
> 1     2   
> 10   5    


table(X[,drop=TRUE])

Uwe Ligges


>  
> Thank a lot,
>  
> Bernard
>  
> 
> 
> 		
> ---------------------------------
> 
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html