I'm not sure that post is 100% correct. Reading it gave me a bad feeling that it missed something I'd read in the past. See here for example ... http://stackov

I'm not sure that post is 100% correct. Reading it gave me a bad feeling that it missed something I'd read in the past. See here for example ... http://stackoverflow.com/questions/1741820/assignment-operators-in-r-and http://stackoverflow.com/questions/1741820/assignment-operat... The = operator is only a "top level" construct, while <- can be used anywhere. Now exactly what those limitations are may be a bit subtle (the OP's point), so I also just use <-.