Just to make sure that you don't spend your valuable time on the problem that I posted earlier today, I want to let you know that I have found my mistake. I simply forgot to take account of the higher order dependence bw my independent variable and the squared error term.
Regards Karl-Oskar ______________________________________________ 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.