spruces               package:spatstat               R Documentation

_S_p_r_u_c_e_s _P_o_i_n_t _P_a_t_t_e_r_n

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

     The data give the locations of Norwegian spruce trees  in a
     natural forest stand in Saxonia, Germany. Each tree is marked with
     its diameter at breast height.

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

     data(spruces)

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

     An object of class '"ppp"' representing the point pattern of tree
     locations in a 56 x 38 metre sampling region. Each tree is marked
     with its diameter at breast height. All values are given in
     metres.

     See 'ppp.object' for details of the format of a point pattern
     object. The marks are numeric.

     These data have been analysed by Fiksel (1984, 1988), Stoyan et al
     (1987), Penttinen et al (1992) and Goulard et al (1996).

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

     Stoyan et al (1987). Original source unknown.

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

     Fiksel, T. (1984) Estimation of parameterized pair potentials of
     marked and nonmarked Gibbsian point processes. _Elektron.
     Informationsverarb. u. Kybernet._ *20*, 270-278.

     Fiksel, T. (1988) Estimation of interaction potentials of Gibbsian
     point processes. _Statistics_ *19*, 77-86

     Goulard, M., S\"arkk\"a, A. and Grabarnik, P. (1996) Parameter
     estimation for marked {G}ibbs point processes through the maximum
     pseudolikelihood method. _Scandinavian Journal of Statistics_
     *23*, 365-379.

     Penttinen, A., Stoyan, D. and Henttonen, H. (1992) Marked point
     processes in forest statistics. _Forest Science_ *38*, 806-824.

     Stoyan, D., Kendall, W.S. and Mecke, J. (1987) _Stochastic
     Geometry and its Applications_. Wiley.

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

          data(spruces)
          plot(spruces)
          # To reproduce Goulard et al. Figure 3
          plot(spruces, maxsize=5*max(spruces$marks))
          plot(unmark(spruces), add=TRUE)

