Covariate.varFunc            package:nlme            R Documentation

Assign varFunc Covariate

Description:

     The covariate(s) used in the calculation of the weights of the
     variance function represented by 'object' is (are) replaced by
     'value'. If 'object' has been initialized, 'value' must have the
     same dimensions as 'getCovariate(object)'.

Usage:

     ## S3 replacement method for class 'varFunc':
     covariate(object) <- value

Arguments:

  object: an object inheriting from class 'varFunc', representing a
          variance function structure.

   value: a value to be assigned to the covariate associated with
          'object'.

Value:

     a 'varFunc' object similar to 'object', but with its 'covariate'
     attribute replaced by 'value'.

Author(s):

     Jose Pinheiro Jose.Pinheiro@pharma.novartis.com and Douglas Bates
     bates@stat.wisc.edu

See Also:

     'getCovariate.varFunc'

Examples:

     vf1 <- varPower(1.1, form = ~age)
     covariate(vf1) <- Orthodont[["age"]]

