“…Because the likelihood function does not have a closed form, either a numerical approximation such as the Gauss‐Hermite quadrature
24 or an EM algorithm may be used to estimate the parameters of interest, that is,
. Gigante
25 developed a numerical estimating procedure for the joint mixed effects model on the number of health insurance payments and the increment payments, in the context of the sleep model, on
. Specifically, they used a hierarchical likelihood approach
26 and an iterative weighted least square algorithm.…”