> On 10 Nov 2016, at 16:30 , erlis ruli <erlis.r...@gmail.com> wrote: > > Here comes the questions. Is it possible to modify Helmert contrasts in order > to use weighted means instead of means of means?
I think not. Not in general. I suppose you can set up a contrast matrix that would make the intercept equal to the overall mean, but the definition would depend on the group sizes. Contrast matrices are by design something that specifies a mapping FROM parameter space TO observation space and shouldn't depend on which observations you have or don't have. Put differently, you would have to modify the entire design matrix if you removed a few rows. -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Office: A 4.23 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ 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.
