Dieter Menne <[EMAIL PROTECTED]> writes: > Andreas Cordes <andreas.cordes <at> stud.uni-goettingen.de> writes: > > > > > Hi, > > I would like to fit a model for a factorial design that allows for > > unequal variances in all groups. If I am not mistaken, this can be done > > in lm by specifying weights. > > > A function intended to specify weights for unequal variance structures > > is provided in the nlme library with the varIdent function. Is it > > apropriate to use these weights with lm? If not, is there another > > possibility to do factorial designs with heteroscedasticity? > > No, varIdent and friends is made for use with mixed effect models in package > nlme.
- or with generalized least squares, using the gls() function in the same package. -- O__ ---- Peter Dalgaard Ă˜ster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html