You're right, it is the same. using I() won't work for the same reason sqrt don't, so :
> x2 <- x^2 > lrm(y~x+x2) Thx for the correction. Cheers Joris On Thu, Jun 3, 2010 at 6:14 PM, Bert Gunter <gunter.ber...@gene.com> wrote: > Below. -- Bert > > Bert Gunter > Genentech Nonclinical Biostatistics > -------------------------------------- > But you wrote linear+ square. Don't you mean: > lrm(Y~x+x^2) > > --- I believe this is the same as lrm(Y ~ x). > You must protect the x^2 via > > lrm(Y ~ x + I(x^2)) > > ------------------------------------------ > > -- Joris Meys Statistical Consultant Ghent University Faculty of Bioscience Engineering Department of Applied mathematics, biometrics and process control Coupure Links 653 B-9000 Gent tel : +32 9 264 59 87 joris.m...@ugent.be ------------------------------- Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php [[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.
