Because there is also a symmetric difference: see http://en.wikipedia.org/wiki/Symmetric_difference
Sorry if this is a silly question. What does asymmetric refer to from ?intersect, and are there any aspects of the result that may be different from expected (reason for exclamation point) ? As toy data, if needed, here are the examples from the help page. (x <- c(sort(sample(1:20, 9)),NA)) (y <- c(sort(sample(3:23, 7)),NA)) Thanks, Juliet
-- Brian D. Ripley, rip...@stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ 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.
