

ToothGrowth {base}                           R Documentation

_T_h_e _E_f_f_e_c_t _o_f _V_i_t_a_m_i_n _C _o_n _T_o_o_t_h _G_r_o_w_t_h _i_n _G_u_i_n_e_a _P_i_g_s

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

     The response is the length of odontoblasts (teeth) in
     each of 10 guinea pigs at each of three dose levels of
     Vitamin C (0.5, 1, and 2 mg) with each of two delivery
     methods (orange juice or ascorbic acid).

_U_s_a_g_e_:

     data(ToothGrowth)

_F_o_r_m_a_t_:

     A data frame with 60 observations on 3 variables.

      [,1]      len       numeric      Tooth length
      [,2]      supp      factor       Supplement type (VC or OJ).
      [,3]      dose      numeric      Dose in milligrams.

_S_o_u_r_c_e_:

     C. I. Bliss (1952).  The Statistics of Bioassay, Aca-
     demic Press.

_R_e_f_e_r_e_n_c_e_s_:

     McNeil, D. R. (1977).  Interactive Data Analysis.  New
     York: Wiley.

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

     data(ToothGrowth)
     coplot(len ~ dose | supp, data = ToothGrowth, panel = panel.smooth,
            xlab = "ToothGrowth data: given is supplement type")

