geary                 package:spdep                 R Documentation

_C_o_m_p_u_t_e _G_e_a_r_y'_s _C

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

     A simple function to compute Geary's C, called by 'geary.test' and
     'geary.mc';

 C = frac{(n-1)}{2sum_{i=1}^{n}sum_{j=1}^{n}w_{ij}} frac{sum_{i=1}^{n}sum_{j=1}^{n}w_{ij}(x_i-x_j)^2}{sum_{i=1}^{n}(x_i - bar{x})^2}

     'geary.intern' is an internal function used to vary the similarity
     criterion.

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

     geary(x, listw, n, n1, S0, zero.policy=FALSE)

_A_r_g_u_m_e_n_t_s:

       x: a numeric vector the same length as the neighbours list in
          listw

   listw: a 'listw' object created for example by 'nb2listw'

       n: number of zones

      n1: n - 1

      S0: global sum of weights

zero.policy: if TRUE assign zero to the lagged value of zones without
          neighbours, if FALSE assign NA

_V_a_l_u_e:

     a list with 

       C: Geary's C

       K: sample kurtosis of x

_A_u_t_h_o_r(_s):

     Roger Bivand Roger.Bivand@nhh.no

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

     Cliff, A. D., Ord, J. K. 1981 Spatial processes, Pion, p. 17.

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

     'geary.test', 'geary.mc',  'sp.mantel.mc'

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

     data(oldcol)
     col.W <- nb2listw(COL.nb, style="W")
     str(geary(COL.OLD$CRIME, col.W, length(COL.nb), length(COL.nb)-1,
      Szero(col.W)))

