On Fri, Dec 5, 2008 at 6:50 AM, Antje <[EMAIL PROTECTED]> wrote:
> Hello,
>
> I hope this question is not too stupid. I would like to know how to update
> levels after subsetting data from a data.frame.
>
> df <- data.frame(factor(c("a","a","c","b","b")), c(4,5,6,7,8), c(9,1,2,3,4))
> names(df) <- c("X1","X2","X3")
>
> my.sub <- subset(df, X1 == "a" | X1 == "b")
> levels(my.sub$X1)
>
> # still gives me "a","b","c", though the subset does not contain entries
> with "c" anymore
>
> I guess, the solution is rather simple, but I cannot find it.You might find it easier just to work with character vectors: options(stringsAsFactors = FALSE) Hadley -- http://had.co.nz/ ______________________________________________ R-help@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.
