This function is a constructor for the varComb class,
representing a combination of variance functions. The corresponding
variance function is equal to the product of the variance functions of
the varFunc objects listed in ....
Usage
varComb(...)
Arguments
...
objects inheriting from class varFunc representing
variance function structures.
Value
a varComb object representing a combination of variance
functions, also inheriting from class varFunc.
References
Pinheiro, J.C., and Bates, D.M. (2000) "Mixed-Effects Models
in S and S-PLUS", Springer.