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 )