It's hard to say what exactly goes wrong without a reproducible example (see the posting guide). However, a typical source of such problems is that some regressors are scaled badly. Maybe you have one regressor that takes very large values or squares of a regressor that takes moderately large values? The result would be that the associated coefficients become tiny and the hessian is conditioned badly. The simple solution is to scale the problematic regressor so that it's coefficient is reasonably sized (e.g., divide by 1000 or 10000 or so).


(sent from mobile phone)

-------- Original message --------
Subject: [R] zeroinfl problem: cannot get standard errors, hessian has NaN 
From: nikkks <nikita@sagowarrior.com> 
To: r-help@r-project.org 
CC:  

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.

	[[alternative HTML version deleted]]

