Initialize.varFunc {nlme} | R Documentation |
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.
## S3 method for class 'varFunc': Initialize(object, data, ...)
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) . |
... |
this argument is included to make this method compatible with the generic. |
an initialized object with the same class as object
representing a variance function structure.
Jose Pinheiro Jose.Pinheiro@pharma.novartis.com and Douglas Bates bates@stat.wisc.edu
vf1 <- varPower( form = ~ age | Sex ) vf1 <- Initialize( vf1, Orthodont )