Hello, I am looking at a data set predicting number of plants (FERO) based on fixed effects sowing method (Method) and sowing rate (Rate). I also have a slope random effect for the site and intercept random effects for the nested variables Block and Strip.ID (to account for experimental design). I have tried running several different models using the glmmadmb function. The dependent variable, FERO, is a discrete count. All of my fixed and random effects are categorical and have the following levels:
Method: 3 Rate: 5 Site: 3 Block: 18 Strip.ID: 275 The following model runs without a problem: fit_nbin3 <-glmmadmb(FERO ~ Method * Rate + (FERO|Site) + (1|Block/Strip.ID), data = data1, family = "nbinom") However, when I try to run the same model without the interaction term: fit_nbin4 <-glmmadmb(FERO ~ Method + Rate + (FERO|Site) + (1|Block/Strip.ID), + data = data1, family = "nbinom") I get the following error message: Parameters were estimated, but not standard errors were not: the most likely problem is that the curvature at MLE was zero or negative Error in glmmadmb(FERO ~ Method + Rate + (FERO | Site) + (1 | Block/Strip.ID), : The function maximizer failed (couldn't find STD file) Troubleshooting steps include (1) run with 'save.dir' set and inspect output files; (2) change run parameters: see '?admbControl' In addition: Warning message: running command 'C:\windows\system32\cmd.exe /c "C:/Users/Cara/Documents/R/win-library/3.1/glmmADMB/bin/windows64/glmmadmb.exe" -maxfn 500 -maxph 5 -noinit -shess' had status 1 I am confused as why removing the interaction term, which should simplify the model is causing it to fail to run correctly. Any ideas what's going on here? Here is a sample of my first few lines of data: Site Method Rate Block Strip FERO Glacial Broadcast A A H 69 Glacial Broadcast A A H 1 Glacial Broadcast A A H 41 One other quick thing: I can't seem to the the aictab function to work on the properly run glmmadmb models. I get a message saying: Error in formatCands(cand.set) : Functions do not support mixture of model classes Thanks in advance for your help! Cara Applestein Prairie Science Technician Center for Natural Lands Management Olympia, Washington -- View this message in context: http://r.789695.n4.nabble.com/glmmADMB-model-fails-when-fixed-effect-interaction-term-is-removed-tp4701411.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
