x == NULL returns logical(0) instead of FALSE or TRUE as you might expect and I cannot find the right way to write this test in R.
Thanks in advance for any hint, -- O.L. ______________________________________________ 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.
