coef.varFunc              package:nlme              R Documentation

varFunc Object Coefficients

Description:

     This method function extracts the coefficients associated with the
     variance function structure represented by 'object'.

Usage:

     ## S3 method for class 'varFunc':
     coef(object, unconstrained, allCoef, ...)
     ## S3 method for class 'varIdent':
     coef(object, ...) <- value

Arguments:

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

unconstrained: a logical value. If 'TRUE' the coefficients are returned
          in unconstrained form (the same used in the optimization
          algorithm). If 'FALSE' the coefficients are returned in
          "natural", generally constrained form. Defaults to 'TRUE'.

 allCoef: a logical value. If 'FALSE' only the coefficients which may
          vary during the optimization are returned. If 'TRUE' all
          coefficients are returned. Defaults to 'FALSE'.

   value: a vector with the replacement values for the coefficients
          associated with 'object'. It must be have the same length of
          'coef{object}' and must be given in unconstrained form.
          'Object' must be initialized before new values can be
          assigned to its coefficients.

     ...: some methods for this generic require additional arguments. 
          None are used in this method.

Value:

     a vector with the coefficients corresponding to 'object'.

SIDE EFFECTS:

     On the left side of an assignment, sets the values of the
     coefficients of 'object' to 'value'.

Author(s):

     Jose Pinheiro and Douglas Bates

See Also:

     'varFunc'

Examples:

     vf1 <- varPower(1)
     coef(vf1)
     coef(vf1) <- 2

