working.compNP: Internal Function
Description
It efficiently calculates the working model quantities in the presence of nonparametric random effects
needed to implement the automatic multiple smoothing parameter
procedure.References
Marra G., Papageorgiou G. and Radice R. (in press), Estimation of a Semiparametric Recursive Bivariate Probit Model with Nonparametric Mixing. Australian & New Zealand Journal of Statistics.