Regress on a multivariate polynomial: lm(y ~ polym(x1, x2, x3, x4, degree = 3))
See ?polym ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.