Hello I am trying to reproduce a mixed regression model published in (J Evol Biol 12:94-102) with PASW 17.03. The authors used SAS to fit the model using the following syntaxis:
proc mixed nobound; class area individ trait; model a = side trait area side*trait side*area trait*area/ddfm = satterthwaite solution; random intercept side/subject = individ group = areatrai; repeated/local = quad(areatrai) subject = individ; run; The model specifies separate variance components and error variances for the grouping "areatrai" variable. This is indicated by "group= areatrai" and "local = quad (areatrai)", respectively. Since I currently have no access to SAS and this part of the analysis is absolutely central to my research, I would be very grateful if someone can tell whether it is possible to model the variance and error by group using lme or any other R package for linear mixed models. Any help will be much appreciated. Thanks -- View this message in context: http://r.789695.n4.nabble.com/lme-model-variance-and-error-by-group-tp2226207p2226207.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.