I have tried glm.nb in the MASS package, but many models (I have 250 models with different combinations of predictors for fish counts data) either fail to converge or even diverge.
I'm attempting to use the negbin function in the AOD package, but am unsure what to use for the "random" term, which is supposed to provide a right hand formula for the overdispersion parameter. I'm not even sure what this statement means. Any advice you have would be greatly appreciated. negbin(formula, random, data, phi.ini = NULL, warnings = FALSE, na.action = na.omit, fixpar = list(), hessian = TRUE, control = list(maxit = 2000), ...) My largest model using glm.nb looks like this: negBin.glm1 <- glm.nb(Count ~ offset(log(Tow.Area)) + Basin + Bathy + Hypoxia + Period + Depth + Basin*Depth + Bathy*Depth + Hypoxia*Depth + Period*Depth + Basin*Period + Bathy*Period + Hypoxia*Period + Hypoxia:Period:Depth + Bathy:Period:Depth + Basin:Period:Depth, control=glm.control(maxit=1000), method="glm.fit", data=Combined.Counts.df) How could I adjust this to function with the "negbin" function? Specifically, what would I use for the required "random" term? Caroline E. Paulsen Masters Candidate School of Aquatic and Fishery Sciences University of Washington phone: 206.852.9539 email: [EMAIL PROTECTED] [[alternative HTML version deleted]] ______________________________________________ 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.