Hi, This is not nearly enough information. Please follow the posting guide and provide us with a reproducible example, or at the bare minimum, the code for your models. Without more details we can only wildly guess, but here are a few:
---You have more parameters than your data can support (the Hessian is the matrix of partial second derivatives, and SEs are typically based closely on the hessian (or rather the information matrix, the negative of the hessian). ---you have some redundant effects? Try a simpler model and see if you can find some particular parameter that leads to the problem. You could also try tweaking optimization options, but I that is usually not the source of the problem. We really need more information, with the ideal being putting data that reproduces your problem (or your actual data) online somewhere where we can easily download it, and providing us with all your model code, so on our machines, we can exactly reproduce what is happening for you and try to troubleshoot. Cheers, Josh On Tue, Jul 24, 2012 at 10:50 PM, nikkks <nik...@sagowarrior.com> wrote: > Hi! > > I have three models. > > > > In the first model, everything is fine. > > > > > However, in the second and third models, I have NA's for standard errors: > > > > > > The hessians also have NaN's (same for m2 and m3). > > > > What should I do about it? It there a way to obtain the hessian without > transforming my variables? I will greatly appreciate your help! > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/zeroinfl-problem-cannot-get-standard-errors-hessian-has-NaN-tp4637715.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. -- Joshua Wiley Ph.D. Student, Health Psychology Programmer Analyst II, Statistical Consulting Group University of California, Los Angeles https://joshuawiley.com/ ______________________________________________ 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.