glmer with nAGQ > 1

Viechtbauer Wolfgang (STAT <wolfgang.viechtbauer at ...> writes:

I just tried to fit a mixed-effects logistic regression model with
version 0.99999911-5 of lme4 (installed from github). The model
includes a random effect for clusters and a random group/treatment
effect. I received the following error:

Error in updateGlmerDevfun(devfun, glmod$reTrms, nAGQ = nAGQ) : nAGQ

  > 1 is only available for models with a single, scalar

  random-effects term

Indeed, I had set nAGQ > 1 to get more precision with the evaluation
of the integrals via Gauss-Hermite quadrature. It's clear what the
error message says, but I am wondering if this is going to be a
permanent design choice or something temporary.

It's probably a "foreseeable future" decision (alas).

   I don't know the guts of the AGQ calculation tremendously well,
so I don't know exactly what would be involved in constructing
a multi-dimensional AGQ.  Taking a brief look back at lme4.0/old-lme4,
it seems that only a single _grouping variable_ was allowed, but 
it was not limited to scalar random effects terms, so it might
not be too horrible to re-implement ... but it's not on the
urgent "to do" list at the moment ...  (Anyone want to volunteer
to take a look at the code and implement this ???)

  Ben