[R-sig-ME] Comparison of crossed ranom effects: lmer vs. MCMCglmm

Linus Holtermann holtermann at hwwi.org
Mon Jan 19 18:39:52 CET 2015


I read that lmer can handle independent (often labelled as crossed) random effets in mixed models. It seems to be possible with MCMCglmm as long as groups for the random effects are uniquely labelled. I use the "Penicllin" data in the lme4-package to compare both approaches:



ml <- lmer(diameter~ 1 + (1|plate)+ (1|sample))

mcmc <- MCMCglmm(diameter~ 1, random=~ plate + sample,verbose=F, nitt=110000,burn=10000,thin=10,data=Penicillin)

Why are the result for the plate-variance differ by a large amount? Is it because MCMCglmm applies Gibbs sampling? Or is MCMCglmm doing something else here, instead of fitting independent random effects?

Best regards,

Linus Holtermann
Hamburgisches WeltWirtschaftsInstitut gemeinnützige GmbH (HWWI)
Heimhuder Straße 71
20148 Hamburg
Tel +49-(0)40-340576-336
Internet: www.hwwi.org
Email: holtermann at hwwi.org
Amtsgericht Hamburg HRB 94303
Geschäftsführer: PD Dr. Christian Growitsch | Prof. Dr. Henning Vöpel
Prokura: Dipl. Kauffrau Alexis Malchin
Umsatzsteuer-ID: DE 241849425

More information about the R-sig-mixed-models mailing list