> wtf <- factor(x, levels(c(levels(wtf), NA), exclude=NULL) > xtabs (~ wtf, exclude=NULL, na.action=na.pass)
Also see addNA. 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.
