A generalized least squares structure is a list of model components representing different sets of parameters in the linear model. A glsStruct may contain corStruct and varFunc objects. NULL arguments are not included in the glsStruct list.
glsStruct(corStruct, varStruct)
Arguments
corStruct: an optional corStruct object, representing a correlation structure. Default is NULL.
varStruct: an optional varFunc object, representing a variance function structure. Default is NULL.
Returns
a list of model variance-covariance components determining the parameters to be estimated for the associated linear model.