getisord                package:spdep                R Documentation

_G_e_t_i_s-_O_r_d _r_e_m_o_t_e _s_e_n_s_i_n_g _e_x_a_m_p_l_e _d_a_t_a

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

     The 'xyz' data frame has 256 rows and 3 columns. Vectors 'x'  and
     'y' are of length 16 and give the centres of the grid rows and
     columns, 30m apart. The data start from the bootom left, Getis and
     Ord start from the top left - so their 136th grid cell is our
     120th.

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

     data(getisord)

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

     This data frame contains the following columns:

     _x grid eastings

     _y grid northings

     _v_a_l remote sensing values

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

     Getis, A. and Ord, J. K. 1996 Local spatial statistics: an
     overview. In P. Longley and M. Batty (eds) _Spatial analysis:
     modelling in a GIS environment_ (Cambridge: Geoinformation
     International), 266.

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

     data(getisord)
     image(x, y, t(matrix(xyz$val, nrow=16, ncol=16, byrow=TRUE)), asp=1)
     text(xyz$x, xyz$y, xyz$val, cex=0.7)
     polygon(c(195,225,225,195), c(195,195,225,225), lwd=2)
     title(main="Getis-Ord 1996 remote sensing data")

