NLSstLfAsymptote            package:stats            R Documentation

_H_o_r_i_z_o_n_t_a_l _A_s_y_m_p_t_o_t_e _o_n _t_h_e _L_e_f_t _S_i_d_e

_D_e_s_c_r_i_p_t_i_o_n:

     Provide an initial guess at the horizontal asymptote on the left
     side (i.e., small values of 'x') of the graph of 'y' versus 'x'
     from the 'xy' object.  Primarily used within 'initial' functions
     for self-starting nonlinear regression models.

_U_s_a_g_e:

     NLSstLfAsymptote(xy)

_A_r_g_u_m_e_n_t_s:

      xy: a 'sortedXyData' object

_V_a_l_u_e:

     A single numeric value estimating the horizontal asymptote for
     small 'x'.

_A_u_t_h_o_r(_s):

     Jose Pinheiro and Douglas Bates

_S_e_e _A_l_s_o:

     'sortedXyData', 'NLSstClosestX', 'NLSstRtAsymptote', 'selfStart'

_E_x_a_m_p_l_e_s:

     DNase.2 <- DNase[ DNase$Run == "2", ]
     DN.srt <- sortedXyData( expression(log(conc)), expression(density), DNase.2 )
     NLSstLfAsymptote( DN.srt )

