Message-ID: <loom.20120317T212658-250@post.gmane.org>
Date: 2012-03-17T21:03:55Z
From: Ben Bolker
Subject: Poisson GLMM: where is the deviance?
Luciano La Sala <lucianolasala at ...> writes:
>
[snip]
> Where "stake" (plots where the number of birds is measured) is as random
> effect, and "yobs" is the abundance of birds. I need an estimation of slope
> an intercept for the random term.
>
> I specified my model as follows:
>
> glmer(yobs~year + (year|stake), data=mibase,family=poisson)
>
> and I get the following (it does not calculate the deviance)
>
> ? Generalized linear mixed model fit by the Laplace approximation
>
[snip]
> Q. What does this error mean and how can I solve it?
>
> By the way, if I run the same model but only estimating the intercept of
> random effects as
> glmer(yobs~year + (1|stake), data=mibase,family=poisson) it seems to work
> properly.
You aren't doing anything obviously silly, that I can see.
Can we see a str() of your data? I wonder if your 'year' variable
got turned into a factor by mistake.
How many stakes do you have? If it is fewer than 5-6 you are likely
to have numerical problems ...
When in doubt plot your data ...