nztrees               package:spatstat               R Documentation

_N_e_w _Z_e_a_l_a_n_d _T_r_e_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 trees in a forest plot.

     They were collected by Mark and Esler (1970) and were extracted
     and analysed by Ripley (1981, pp. 169-175).  They represent the 
     positions of 86 trees in a forest plot approximately 140 by 85
     feet.

     Ripley discarded from his analysis the eight trees at the
     right-hand edge of the plot (which appear to be part of a planted
     border) and trimmed the window by a 5-foot margin accordingly.

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

     data(nztrees)

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

     An object of class `"ppp"' representing the point pattern of tree
     locations. The Cartesian coordinates are in feet.

     See `ppp.object' for details of the format of a point pattern
     object.

_N_o_t_e:

     To trim a 5-foot margin off the window, type `nzsub <- nztrees[ ,
     owin(c(0,148),c(0,95)) ]'

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

     Mark and Esler (1970), Ripley (1981).

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

     Ripley, B.D. (1981)  Spatial statistics. John Wiley and Sons.

     Mark, A.F. and Esler, A.E. (1970) An assessment of the
     point-centred quarter method of plotless sampling in some New
     Zealand forests. Proceedings of the New Zealand Ecological Society
     17, 106-110.

