redwoodfull             package:spatstat             R Documentation

_C_a_l_i_f_o_r_n_i_a _R_e_d_w_o_o_d_s _P_o_i_n_t _P_a_t_t_e_r_n (_E_n_t_i_r_e _D_a_t_a_s_e_t)

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

     These data represent the locations of 195 seedlings and saplings 
     of California redwood trees in a square sampling region.   They
     were described and analysed by Strauss (1975). This is the
     ``*full*'' dataset; most writers have analysed a subset extracted
     by Ripley (1977) which is available as 'redwood'.

     Strauss (1975) divided the sampling region into two subregions I
     and II demarcated by a diagonal line across the region. The
     spatial pattern appears to be slightly regular in region I and
     strongly clustered in  region II.

     The dataset 'redwoodfull' contains the full point pattern of 195
     trees.  The auxiliary information about the subregions is
     contained in  'redwoodfull.extra', which is a list with entries

       'diag'      The coordinates of the diagonal boundary
                   between regions I and II
       'regionI'   Region I as a window object
       'regionII'  Region II as a window object
       'regionR'   Ripley's subrectangle (approximate)
       'plot'      Function to plot the full data and auxiliary markings

     Ripley (1977) extracted a subset of these data, containing 62
     points, lying within a square subregion which overlaps regions I
     and II. He rescaled the data to the unit square.  This has been
     re-analysed many times, and is the dataset usually known as ``the
     redwood data'' in the spatial statistics literature. The exact
     dataset used by Ripley is supplied in the 'spatstat' library as
     'redwood'. There are some minor inconsistencies with 'redwood'
     since it originates from a different digitisation.

     The approximate position of the square chosen by Ripley within the
     'redwoodfull' pattern is indicated by the window
     'redwoodfull.extra$regionR'.

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

     data(redwoodfull)

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

     The dataset 'redwoodfull' is an object of class '"ppp"'
     representing the point pattern of tree locations. The window has
     been rescaled to the unit square. See 'ppp.object' for details of
     the format of a point pattern object.

     The dataset 'redwoodfull.extra' is a list with entries

       'diag'      coordinates of endpoints of a line,
                   in format 'list(x=numeric(2),y=numeric(2))'
       'regionI'   a window object
       'regionII'  a window object
       'regionR'   a window object
       'plot'      Function with no arguments

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

     Strauss (1975). The plot of the data published by Strauss (1975)
     was scanned and digitised by Sandra Pereira, University of Western
     Australia, 2002.

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

     Diggle, P.J. (1983) _Statistical analysis of spatial point
     patterns_. Academic Press.

     Ripley, B.D. (1977) Modelling spatial patterns (with discussion).
     _Journal of the Royal Statistical Society, Series B_ *39*,
     172-212.

     Strauss, D.J. (1975) A model for clustering. _Biometrika_ *63*,
     467-475.

_S_e_e _A_l_s_o:

     'redwood'

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

            data(redwoodfull)
            plot(redwoodfull)
            redwoodfull.extra$plot()
            # extract the pattern in region II 
            redwoodII <- redwoodfull[, redwoodfull.extra$regionII]

