fgl package:MASS R Documentation _M_e_a_s_u_r_e_m_e_n_t_s _o_f _F_o_r_e_n_s_i_c _G_l_a_s_s _F_r_a_g_m_e_n_t_s _D_e_s_c_r_i_p_t_i_o_n: The 'fgl' data frame has 214 rows and 10 columns. It was collected by B. German on fragments of glass collected in forensic work. _U_s_a_g_e: fgl _F_o_r_m_a_t: This data frame contains the following columns: '_R_I' refractive index; more precisely the refractive index is 1.518xxxx. The next 8 measurements are percentages by weight of oxides. '_N_a' sodium. '_M_g' manganese. '_A_l' aluminium. '_S_i' silicon. '_K' potassium. '_C_a' calcium. '_B_a' barium. '_F_e' iron. '_t_y_p_e' The fragments were originally classed into seven types, one of which was absent in this dataset. The categories which occur are window float glass ('WinF': 70), window non-float glass ('WinNF': 76), vehicle window glass ('Veh': 17), containers ('Con': 13), tableware ('Tabl': 9) and vehicle headlamps ('Head': 29). _R_e_f_e_r_e_n_c_e_s: Venables, W. N. and Ripley, B. D. (2002) _Modern Applied Statistics with S._ Fourth edition. Springer.