

IQR {base}                                   R Documentation

_T_h_e _I_n_t_e_r_q_u_a_r_t_i_l_e _R_a_n_g_e

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

     computes interquartile range of the `x' values.

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

     IQR(x, na.rm = FALSE)

_D_e_t_a_i_l_s_:

     Note that this function computes the quartiles using
     the `quantile' function rather than following Tukey's
     recommendations, i.e., `IQR(x) = quantile(x,3/4) -
     quantile(x,1/4)'.

     For normally N(m,1) distributed X, the expected value
     of `IQR(X)' is `2*qnorm(3/4) = 1.3490', i.e., for a
     normal-consistent estimate of the standard deviation,
     use `IQR(x) / 1.349'.

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

     Tukey, J. W. (1977).  Exploratory Data Analysis.  Read-
     ing: Addison-Wesley.

_S_e_e _A_l_s_o_:

     `fivenum', `mad' which is more robust, `range', `quan-
     tile'.

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

     data(rivers)
     IQR(rivers)

