Without covariates, Zb0 and Zw0 are estimates of
and respectively. With covariates, Zb1,
Zb2,..., refer to estimates of the elements of the vector
and Zw1, Zw2,..., are estimates of the
elements of . The symbols sigB, sigW, and
rho refer to estimates of , , and .
Finally, the global _Eeta allows and
to be set to fixed values, which are etaB and etaW
(the default for is zero for each).