finpines              package:spatstat              R Documentation

_P_i_n_e _s_a_p_l_i_n_g_s _i_n _F_i_n_l_a_n_d.

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

     The data record the locations of 126 pine saplings in a Finnish
     forest, their heights and their diameters.

     The main dataset 'finpines' is a marked point pattern containing
     the locations of the saplings marked by their heights. Additional
     data in 'finpines.extra' record the sapling diameters.

     Sapling locations are given in metres (to six significant digits);
     heights are in metres (rounded to the nearest 0.1 metre, except in
     one case to the nearest 0.05 metres); diameters are in centimetres
     (rounded to the nearest centimetre).

     The data were recorded by Professor Seppo Kellomaki, Faculty of
     Forestry, University of Joensuu, Finland, and subsequently
     massaged by Professor Antti Penttinen, Department of Statistics,
     University of Jyv\"askyl\"a, Finland.

     Originally the point locations were observed in polar coordinates
     with rather poor angular precision. Hence the coordinates are
     imprecise for large radius because of rounding errors: indeed the
     alignments can be observed by eye.

     The data were manipulated by Prof Penttinen by making small
     angular perturbations at random. After this transformation, the
     original data (in a circular plot) were clipped to a square
     window, for convenience.

     Professor Penttinen emphasises that the data were intended only
     for initial experimentation. They have some strange features. For
     example, if the height is less than 1.3 metres then the diameter
     can be uncertain. Also there are some very close pairs of points.

     These data have subsequently been analysed by Van Lieshout (2004).

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

     data(finpines)

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

     'finpines' is an object of class '"ppp"' representing the point
     pattern of sapling locations marked by their heights. See
     'ppp.object' for details of the format.

     'finpines.extra' is a list with one component 'diameter' which is
     a numeric vector containing the diameters of the points.

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

     Prof Antti Penttinen

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

     Van Lieshout, M.N.M. (2004) A J-function for marked point
     patterns. Research Report PNA-R0404, June 2004. Centrum voor
     Wiskunde en Informatica (CWI), Amsterdam, 2004.

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

         data(finpines)
         plot(unmark(finpines), main="Finnish pines: locations")
         plot(finpines, main="locations and heights")
         plot(finpines %mark% finpines.extra$diameter, main="diameters")

