Earthquake package:nlme R Documentation _E_a_r_t_h_q_u_a_k_e _I_n_t_e_n_s_i_t_y _D_e_s_c_r_i_p_t_i_o_n: The 'Earthquake' data frame has 182 rows and 5 columns. _F_o_r_m_a_t: This data frame contains the following columns: _Q_u_a_k_e an ordered factor with levels '20' < '16' < '14' < '10' < '3' < '8' < '23' < '22' < '6' < '13' < '7' < '21' < '18' < '15' < '4' < '12' < '19' < '5' < '9' < '1' < '2' < '17' < '11' indicating the earthquake on which the measurements were made. _R_i_c_h_t_e_r a numeric vector giving the intensity of the earthquake on the Richter scale. _d_i_s_t_a_n_c_e the distance from the seismological measuring station to the epicenter of the earthquake (km). _s_o_i_l a factor with levels '0' and '1' giving the soil condition at the measuring station, either soil or rock. _a_c_c_e_l maximum horizontal acceleration observed (g). _D_e_t_a_i_l_s: Measurements recorded at available seismometer locations for 23 large earthquakes in western North America between 1940 and 1980. They were originally given in Joyner and Boore (1981); are mentioned in Brillinger (1987); and are analyzed in Davidian and Giltinan (1995). _S_o_u_r_c_e: Pinheiro, J. C. and Bates, D. M. (2000), _Mixed-Effects Models in S and S-PLUS_, Springer, New York. (Appendix A.8) Davidian, M. and Giltinan, D. M. (1995), _Nonlinear Models for Repeated Measurement Data_, Chapman and Hall, London. Joyner and Boor (1981), Peak horizontal acceleration and velocity from strong-motion records including records from the 1979 Imperial Valley, California, earthquake, _Bulletin of the Seismological Society of America_, *71*, 2011-2038. Brillinger, D. (1987), Comment on a paper by C. R. Rao, _Statistical Science_, *2*, 448-450.