SiegelsEx             package:robustbase             R Documentation

_S_i_e_g_e_l'_s _E_x_a_c_t _F_i_t _E_x_a_m_p_l_e _D_a_t_a

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

     A small counterexample data set devised by Andrew Siegel. Six (out
     of nine) data points lie on the line y = 0 such that some robust
     regression estimators exhibit the "_exact fit_" property.

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

     data(SiegelsEx)

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

     A data frame with 9 observations on the following 2 variables.

     '_x' a numeric vector

     '_y' a numeric vector

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

     Emerson and Hoaglin (1983, p.139)

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

     Peter J. Rousseeuw and Annick M. Leroy (1987) _Robust Regression
     and Outlier Detection_ Wiley, p.60-61

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

     data(SiegelsEx)
     plot(SiegelsEx, main = "Siegel's example for 'exact fit'")
     abline(          lm(y ~ x, data = SiegelsEx))
     abline(MASS::lqs(y ~ x, data = SiegelsEx, method = "lms"), col = 2)
     legend("topright", leg = c("lm", "LMS"), col=1:2, lwd=1, inset = 1/20)

