Many thanks to Dr Ripley, who told me to use negative.binomial instead of
neg.bin, and to Dr Lancelot, who pointed toward the excellent aod. My models
are now converging and the output I am getting seems reasonable.
Cheers,
Elizabeth

On 6/9/06, Prof Brian Ripley <ripley@stats.ox.ac.uk> wrote:
>
> Did you consult the help page for neg.bin?
>
> Details:
>
>       These are not intended to be called by the user. Some are for
>       compatibility with earlier versions of MASS (the book).
>
> The book discusses the family negative.binomial() on p.206, and it is that
> which glm.nb uses.




On 6/9/06, Renaud Lancelot < renaud.lancelot@gmail.com> wrote:Hi Elizabeth,

You might want to try the function negbin in package aod (on CRAN)
which uses another parameterization (phi = 1 / theta). There are anova
and AIC methods for this function in the package. The AIC methods
computes AIC and AICc, and setting the argument k to log(n) provides
the BIC. Let me know if you meet problems.

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