variogram              package:spatial              R Documentation

_C_o_m_p_u_t_e _S_p_a_t_i_a_l _V_a_r_i_o_g_r_a_m

_D_e_s_c_r_i_p_t_i_o_n:

     Compute spatial (semi-)variogram of spatial data or residuals.

_U_s_a_g_e:

     variogram(krig, nint, plotit = TRUE, ...)

_A_r_g_u_m_e_n_t_s:

    krig: trend-surface or kriging object with columns 'x', 'y', and
          'z' 

    nint: number of bins used 

  plotit: logical for plotting 

     ...: parameters for the plot 

_D_e_t_a_i_l_s:

     Divides range of data into 'nint' bins, and computes the average
     squared difference for pairs with separation in each bin.  Returns
     results for bins with 6 or more pairs.

_V_a_l_u_e:

     'x' and 'y' coordinates of the variogram and 'cnt', the number of
     pairs averaged per bin.

_S_i_d_e _E_f_f_e_c_t_s:

     Plots the variogram if 'plotit = TRUE'

_R_e_f_e_r_e_n_c_e_s:

     Ripley, B. D. (1981) _Spatial Statistics._ Wiley.

     Venables, W. N. and Ripley, B. D. (2002) _Modern Applied
     Statistics with S._ Fourth edition.  Springer.

_S_e_e _A_l_s_o:

     'correlogram'

_E_x_a_m_p_l_e_s:

     data(topo, package="MASS")
     topo.kr <- surf.ls(2, topo)
     variogram(topo.kr, 25)

