Covariate.varFunc            package:nlme            R Documentation

_A_s_s_i_g_n _v_a_r_F_u_n_c _C_o_v_a_r_i_a_t_e

_D_e_s_c_r_i_p_t_i_o_n:

     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)'.

_U_s_a_g_e:

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

_A_r_g_u_m_e_n_t_s:

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

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

_V_a_l_u_e:

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

_A_u_t_h_o_r(_s):

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

_S_e_e _A_l_s_o:

     'getCovariate.varFunc'

_E_x_a_m_p_l_e_s:

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

