coef.pdMat               package:nlme               R Documentation

_p_d_M_a_t _O_b_j_e_c_t _C_o_e_f_f_i_c_i_e_n_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     This method function extracts the coefficients associated with the
     positive-definite matrix represented by 'object'.

_U_s_a_g_e:

     ## S3 method for class 'pdMat':
     coef(object, unconstrained, ...)
     ## S3 replacement method for class 'pdMat':
     coef(object, ...) <- value

_A_r_g_u_m_e_n_t_s:

  object: an object inheriting from class 'pdMat', representing a
          positive-definite matrix.

unconstrained: a logical value. If 'TRUE' the coefficients are returned
          in unconstrained form (the same used in the optimization
          algorithm). If 'FALSE' the upper triangular elements of the
          positive-definite matrix represented by 'object' are
          returned. Defaults to 'TRUE'.

   value: a vector with the replacement values for the coefficients
          associated with 'object'. It must be a vector with the same
          length of 'coef{object}' and must be given in unconstrained
          form.

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

_V_a_l_u_e:

     a vector with the coefficients corresponding to 'object'.

_S_I_D_E _E_F_F_E_C_T_S:

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

_A_u_t_h_o_r(_s):

     Jose Pinheiro and Douglas Bates

_R_e_f_e_r_e_n_c_e_s:

     Pinheiro, J.C. and Bates., D.M.  (1996) "Unconstrained
     Parametrizations for Variance-Covariance Matrices", Statistics and
     Computing, 6, 289-296.

_S_e_e _A_l_s_o:

     'pdMat'

_E_x_a_m_p_l_e_s:

     coef(pdSymm(diag(3)))