Rick, most likely, either by using the varIdent class, or conditioning the varPower class on sex. See p. 177, and 208-225 of Pinheiro and Bates.
As usual, it's best to frame your question so that the list can send you some relevant code. If you'd like a more focused answer, I suggest that you write some code that generates a sample dataset such as you describe below. Andrew On Thu, Nov 09, 2006 at 02:43:54PM -0500, Rick Bilonick wrote: > Using the weight argument with a variance function in lme (nlme), you > can allow for heteroscedasticity of the within-group error. Is there a > way to do this for the other variance components? For example, suppose > you had subjects, days nested within subjects, and visits nested within > days within subjects (a fully nested two-way design) and you had, say > men and women subjects. Could you allow for differences in the variance > components for men and women? > > Rick B. > > ______________________________________________ > [email protected] 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. -- Andrew Robinson Department of Mathematics and Statistics Tel: +61-3-8344-9763 University of Melbourne, VIC 3010 Australia Fax: +61-3-8344-4599 http://www.ms.unimelb.edu.au/~andrewpr http://blogs.mbs.edu/fishing-in-the-bay/ ______________________________________________ [email protected] 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.
