weighted.mean             package:stats             R Documentation

_W_e_i_g_h_t_e_d _A_r_i_t_h_m_e_t_i_c _M_e_a_n

_D_e_s_c_r_i_p_t_i_o_n:

     Compute a weighted mean of a numeric vector.

_U_s_a_g_e:

     weighted.mean(x, w, na.rm = FALSE)

_A_r_g_u_m_e_n_t_s:

       x: a numeric vector containing the values whose mean is to be
          computed.

       w: a vector of weights the same length as 'x' giving the weights
          to use for each element of 'x'.

   na.rm: a logical value indicating whether 'NA' values in 'x' should
          be stripped before the computation proceeds.

_D_e_t_a_i_l_s:

     If 'w' is missing then all elements of 'x' are given the same
     weight.

     Missing values in 'w' are not handled.

_S_e_e _A_l_s_o:

     'mean'

_E_x_a_m_p_l_e_s:

     ## GPA from Siegel 1994
     wt <- c(5,  5,  4,  1)/15
     x <- c(3.7,3.3,3.5,2.8)
     xm <- weighted.mean(x,wt)