>> I want to (1) create a deep copy of pop, > > I have already said *I* do not know how to create a "deep copy" in R.
Creating a deep copy is easy, because all copies are "deep" copies. You need to try very hard to create a reference in R. 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.