Find the log-likelihood function
find_lfun_glmm(modfr, method, control = NULL)a model frame, the output of find_modfr_glmm
the method used to approximate the likelihood. The options
are "Laplace", "AGQ" (the adaptive Gaussian quadrature approximation,
from lme4), "SR" (the sequential reduction approximation)
and "IS" (an importance sampling approximation).
a list of extra parameters controlling the approximation to the likelihood. See 'Details' for more information.