> nlevels(c("a", "b")) [1] 0 but the documentation in R 2.5.0 (and earlier) says
If the argument is not a 'factor', 'NA' is returned. I hope it isn't too late, I only came across this in a lecture this morning. Best, Torsten ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel