| getCovariate.varFunc {nlme} | R Documentation |
This method function extracts the covariate(s) associated with the
variance function represented by object, if any is present.
## S3 method for class 'varFunc': getCovariate(object, form, data)
object |
an object inheriting from class varFunc,
representing a variance function structure. |
form |
an optional formula specifying the covariate to be
evaluated in object. Defaults to formula(object). |
data |
some methods for this generic require a data
object. Not used in this method. |
if object has a covariate attribute, its value is
returned; else NULL is returned.
Jose Pinheiro Jose.Pinheiro@pharma.novartis.com and Douglas Bates bates@stat.wisc.edu
data(Orthodont) vf1 <- varPower(1.1, form = ~age) covariate(vf1) <- Orthodont[["age"]] getCovariate(vf1)