Hi, The random slopes are deviations. You need to add the fixed effect associated with x to get the actual slopes. Does this deal with your reservations?
Cheers, Jarrod On 12 Oct 2019, at 08:18, Oscar Inostroza <oskinostr...@gmail.com<mailto:oskinostr...@gmail.com>> wrote: Hi, thank you for your attention. My data consists of 1820 observations (species) grouped in 11 levels (I know that it is a lot!). I mean "crazy" estimates because if I run the models separately for each level (i.e. trimmed the database at each level), there is a very strong positive relationship between x and y. However, when running the full model, the slopes and intercepts are very different (e.g. negative or null slopes). El sáb., 12 de oct. de 2019 a la(s) 03:51, HADFIELD Jarrod (j.hadfi...@ed.ac.uk<mailto:j.hadfi...@ed.ac.uk>) escribió: Hi Oscar, The syntax and prior look fine. How many levels of group are there and what do you mean by crazy? Cheers, Jarrod > On 12 Oct 2019, at 04:54, Oscar Inostroza > <oskinostr...@gmail.com<mailto:oskinostr...@gmail.com>> wrote: > > I'm trying to run a mixed phylogenetic model using the function in the > MCMCglmm R package of the same name. In this model, I want to estimate > slopes and intercepts for each level of a given variable (modeled as a > random effect). I tried to run the model with the following code. However, > the estimates of slopes and intercepts for the random effect are crazy! > (i.e. when running separate models for each level, the results are > reasonable) There is something wrong with my code? (in the syntax of the > model, or likely in the prior specification) > > prior<- list(G=list(G1=list(V=1, nu=0.002), G2=list(V=diag(2), nu=2, > alpha.mu<http://alpha.mu/>= rep(0,2), alpha.V=diag(1000,2,2))), R=list(V=1, > nu=0.002)) > > model<-MCMCglmm(y~x, random=~phylo + > us(1+x):group,family="gaussian",ginverse=list(phylo=inv.phylo$Ainv),prior=prior,data=data,nitt=nitt,burnin=burn,thin=thin, > pr=TRUE) > > Cheers > > p.s the same model, but in the syntax used by brms has the form: > > model <- brm(y ~ x +(1|phylo)+(1+x|group), cov_ranef = list(phylo = A)... > > (But it's too slow for my amount of data) > > -- > Oscar > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-phylo mailing list - > R-sig-phylo@r-project.org<mailto:R-sig-phylo@r-project.org> > https://stat.ethz.ch/mailman/listinfo/r-sig-phylo > Searchable archive at http://www.mail-archive.com/r-sig-phylo@r-project.org/ The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. -- Oscar Inostroza Michael Biólogo Magíster Ciencias (m) Zoología Programa Doctorado en Sistemática y Biodiversidad Laboratorio de Ecología Evolutiva y Filoinformática Facultad de Ciencias Naturales Y Oceanográficas Universidad de Concepción Barrio Universitario s/n, Casilla 160-C Concepción, CHILE Fono Oficina: (56) 41 - 220 – 7341 e-mail: oskinostr...@gmail.com<mailto:oskinostr...@gmail.com> oscarinostr...@udec.cl<mailto:oscarinostr...@udec.cl> Pagina Web: http://phyloevolecol.cl/inostroza-michael/ [[alternative HTML version deleted]] _______________________________________________ R-sig-phylo mailing list - R-sig-phylo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-phylo Searchable archive at http://www.mail-archive.com/r-sig-phylo@r-project.org/
