Hi Ted, yes, vglm(..., family=binomialff(mv=TRUE)) does treat each response as independent. You can see that with coef(fit, matrix=TRUE) where fit is the object. If you want to model two dependent binary responses then you can try the VGAM family functions binom2.or(), loglinb2(), binom2.rho().
> So I'm wondering what is to be gained by using vglm instead of > simple glm? Some VGAM family functions handle a multivariate response. Whether they are treated as independent or dependent depends on the specific family function. Handling multivariate responses becomes important when the modelling function is rrvglm(), cqo(), cao() etc. Being able to handle a multivariate response is a good thing, e.g., one can easily plot several response curves simultaneously, as in the last example in the vgam() help file. > I wonderif someone who is familiar with the details of vglm in the > VGAM package can assist me. I'm new to using it, and there doesn;t > seem much in the documentation that's relevant to the question > below. Yes, the documentation (http://www.stat.auckland.ac.nz/~yee/VGAM/download.shtml) is rather patchy. Sorry! Things are developing there, albeit at a slow pace. cheers Thomas ______________________________________________ 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.
