John, Thanks for the tip on that document; after some searching I found a PDF copy of it on the 'Net. It may take me a little while to work through it, but it looks to be full of good info and worth the effort.
I'll also take a look at leaps as I get time. Thanks, Monte [[alternative HTML version deleted]] ______________________________________________ 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.