Extension: crossed RE's
Adds a "day effect" following Millar (2004, Aust NZ J. Stat, 46, p. 543-554)
The following example was considered by Millar (2004, Aust NZ J. Stat, 46, p. 543-554). A "day effect" (v) was added to the original model formulation, yielding
yij = f1,ij /(1 + exp[-(t-f2)/f3]) ] + eij,
f1,ij = f1 + ui + vj
where u is a tree-effect and v is a day-effect. This is an example of a model where the random effects u and v are crossed. Millar (2004) used simulated likelihood to evaluate the marginal likelihood.