Dear all, I'm trying to make multiple comparisons for an lme-object. The data is for an experiment on parental work load in birds, in which adults at different sites were induced to work at one of three levels ('treat'; H, M, L). The response is 'feedings', which is a quantitative measure of nest provisioning per parent per chick per hour. Site is included as a random effect (one male/female pair per site).
My final model takes the following form: feedings ~ treat + year + data^2, random = ~1|site,data=feed.df For this model, I would like to do multiple comparisons on 'treat', using the multcomp package: summary(glht(m4.feed,linfct=mcp(treat="Tukey"))) However, this does not work, and I get the below error message. Error in if (is.null(pkg) | pkg == "nlme") terms(formula(x)) else slot(x, : argument is of length zero Error in factor_contrasts(model) : no ‘model.matrix’ method for ‘model’ found! I suspect this might have quite a straightforward solution, but I'm stuck at this point. Any help would be most appreciated. Sample data below. Kind regards, Andreas Nord Sweden ============== feedings sex site treat year date^2 1.8877888 M 838 H 2009 81 1.9102787 M 247 H 2009 81 1.4647229 M 674 H 2010 121 1.4160590 M 7009 M 2009 144 1.3106749 M 863 M 2010 196 1.2718121 M 61 M 2009 225 1.2799263 M 729 L 2009 256 1.5829564 M 629 L 2009 256 1.4847251 M 299 L 2010 324 1.2463151 M 569 L 2010 324 2.1694169 F 838 H 2009 81 1.5966899 F 247 H 2009 81 2.4136983 F 674 H 2010 121 1.7784873 F 7009 M 2009 144 1.6681317 F 863 M 2010 196 2.3691275 F 61 M 2009 225 2.0672192 F 729 L 2009 256 1.6389902 F 629 L 2009 256 0.9307536 F 299 L 2010 324 1.6786767 F 569 L 2010 324 ============== -- View this message in context: http://r.789695.n4.nabble.com/Problems-with-glht-function-for-lme-object-tp3179128p3179128.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.