[R-sig-ME] new version of lme4 - Log-Likelihood of model returned as "-Inf"

[Ben Bolker]

  Actually, it got stripped by the mailing list software.  Can you post
it somewhere?  (You can also e-mail it to me.)  (Maybe it got censored
because your data frame is called "shits", which I assume is pronounced
"ess-hits" unless these are data on scat samples :-) ?)

 Perhaps you have the Poisson analogue of complete separation, i.e. a
combination of factor levels within which all the responses are zero?
If so, the bglmer function from the blme package might be helpful ...

On 14-02-12 06:14 PM, juwb08 at hampshire.edu wrote:
> 
> ... the dataset failed to attach, so here it is.
> Sorry!
> 
> Quoting juwb08 at hampshire.edu:
> 
>> Hi All,
>>
>> I was working with Poisson glmms in lme4 last year in 2013 using
>> Windows XP, lme4 version 0.999375-16 (2008-06-23) and R version 2.15.1
>> (2012-06-22), evaluating a set of candidate models with AIC to select
>> the best ones.
>>
>> This worked well until I updated lme4 and R last month.
>>
>> I now updated to R version 3.0.2 (2013-09-25) -- "Frisbee Sailing" and
>> lme4 version 1.0-5 (2013-10-24), still Windows XP, and am running the
>> same models again on the same data, and lme4 now returns "-Inf" for
>> the log likelihood, so it can't calculate AIC.
>>
>> Using the previous versions, I got stable values for Log-Likelihoods
>> and calculated AICs with them.
>>
>> Attached is a sample of the dataset and the code I am using.
>>
>> How can I get a Log-Likelihood estimate with the current versions of
>> lme4 and R?
>>
>> Thanks in advance.
>> Justin Baldwin
>>
>> Hampshire College, MA, USA
> 
> 
> 
> 
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