VisualAcuity               package:vcd               R Documentation

_V_i_s_u_a_l _A_c_u_i_t_y _i_n _L_e_f_t _a_n_d _R_i_g_h_t _E_y_e_s

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

     Data from Kendall & Stuart (1961) on unaided vision among 3,242
     men and 7,477 women, all aged 30-39 and employed in the U.K. Royal
     Ordnance factories 1943-1946.

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

     data(VisualAcuity)

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

     A data frame with 32 observations and 4 variables.

     _F_r_e_q frequency of visual acuity measurements.

     _r_i_g_h_t visual acuity on right eye.

     _l_e_f_t visual acuity on left eye.

     _g_e_n_d_e_r factor indicating gender of patient.

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

     M. Friendly (2000), Visualizing Categorical Data: <URL:
     http://euclid.psych.yorku.ca/ftp/sas/vcd/catdata/vision.sas>

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

     M. G. Kendall & A. Stuart (1961), _The Advanced Theory of
     Statistics_, Vol. 2. Griffin, London.

     M. Friendly (2000), _Visualizing Categorical Data_. SAS Institute,
     Cary, NC.

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

     data(VisualAcuity)
     structable(~ gender + left + right, data = VisualAcuity)

