[R-sig-ME] Increasing iteration limit / lmer bug

[Adam D. I. Kramer]

With apologies, after a lot of grepping around and reading pages on the
internet, yes, as you expected, my model is to blame.

That said, I think that it is quite appropriate for commands listed in the
?help page to actually work or do what they say--in the below case, it is
clear that maxIter is being ignored.

If it is the case that a "valid" or "good" or "non-stupid" model will easily
be fit with maxIter=300 and maxFN=900, then there is no reason to allow
users to think they have changed this value when they have not.

Cordially,
Adam

On Wed, 31 Mar 2010, Adam D. I. Kramer wrote:

> Dear colleagues,
>
> 	I am attempting to fit a model in this manner:
>
> l3 <- glmer(mug ~ condition*time +
> (time|cafe),family=binomial,data=data)
>
> ...the model fails to fit, however, noting:
>
> In mer_finalize(ans) : iteration limit reached without convergence (9)
>
> ...so, of course, I read the man page for glmer and added
> control=list(maxIter=3000). However, the program ran for the same amount of
> time (about 10 minutes) and produced the same error (and, incidentally, the
> same output).
>
> So, I believe there to be a bug in glmer such that maxIter is not
> functioning.
>
> I then upped maxFN, too, (also to 3000) in case that was the problem, but
> found no meaningful difference in the model produced or the time taken to
> fit the model.
>
> Could somebody recommend a workaround? I would like to fit this model.
>
> (running R 2.10.1, lme4 v. 0.999375-32)
>
> Also, in case it matters, 'time' here is a categorical variable
> reperesenting several within-subjects timepoints--there are some other
> (unanswered) posts to this list in which people appear to have fairly
> complex within-subjects effects. Perhaps the issue is that the defaults
> which are in place are insufficiently high for moderately complex
> within-subjects models?
>
> Cordially,
> Adam D. I. Kramer
>
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