This method initializes
object by evaluating its associated
covariate(s) and grouping factor, if any is present, in
data;
determining if the covariate(s) need to be updated when the
values of the coefficients associated with
object change;
initializing the log-likelihood and the weights associated with
object
; and assigning initial values for the coefficients in
object
, if none were present. The covariate(s) will only be
initialized if no update is needed when
coef(object) changes.
USAGE:
initialize(object, data, ...)
REQUIRED ARGUMENTS:
object
an object inheriting from class
varFunc,
representing a variance function structure.
data
a data frame in which to evaluate the variables named in
formula(object).
OPTIONAL ARGUMENTS:
...
this argument is included to make this method compatible
with the generic.
VALUE:
an initialized object with the same class as
object
representing a variance function structure.