humberside             package:spatstat             R Documentation

_H_u_m_b_e_r_s_i_d_e _D_a_t_a _o_n _C_h_i_l_d_h_o_o_d _L_e_u_k_a_e_m_i_a _a_n_d _L_y_m_p_h_o_m_a

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

     Spatial locations of cases of childhood leukaemia and lymphoma,
     and randomly-selected controls, in North Humberside. A marked
     point pattern.

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

     data(humberside)

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

     The dataset 'humberside' is an object of class '"ppp"'
     representing a marked point pattern. Entries include

       'x'      Cartesian x-coordinate of home address
       'y'      Cartesian y-coordinate of home address
       'marks'  factor with levels 'case' and 'control'
                indicating whether this is a disease case
                or a control.

     See 'ppp.object' for details of the format.

     The dataset 'humberside.convex' is an object of the same format,
     representing the same point pattern data, but contained in a
     larger, 5-sided convex polygon.

_N_o_t_e_s:

     Cuzick and Edwards (1990) first presented and analysed these data.

     The data record 62 cases of childhood leukaemia and lymphoma
     diagnosed in the North Humberside region of England between 1974
     and 1986, together with 141 controls selected at random from the
     birth register for the same period.

     The data are represented as a marked point pattern, with the
     points giving the spatial location of each individual's home
     address (actually, the centroid for the postal code) and the marks
     identifying cases and controls.

     Coordinates are in multiples of 100 metres, and the resolution is
     100 metres.

     Two versions of the dataset are supplied, both containing the same
     point coordinates, but using different windows. The dataset
     'humberside' has a polygonal window with 102 edges which closely
     approximates the Humberside region, while 'humberside.convex' has
     a convex 5-sided polygonal window  originally used by Diggle and
     Chetwynd (1991) and shown in Figure 1 of that paper.

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

     Dr Ray Cartwright and Dr Freda Alexander. Published and analysed
     in Cuzick and Edwards (1990), see Table 1. Pentagonal boundary
     from Diggle and Chetwynd (1991), Figure 1. Point coordinates and
     pentagonal boundary supplied by Andrew Lawson. Detailed region
     boundary was digitised by Adrian Baddeley, 2005, from a reprint of
     Cuzick and Edwards (1990).

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

     J. Cuzick and R. Edwards (1990) Spatial clustering for
     inhomogeneous populations. Journal of the Royal Statistical
     Society, series B, 52 (1990) 73-104.

     P.J. Diggle and A.G. Chetwynd (1991) Second-order analysis of
     spatial clustering for inhomogeneous populations. Biometrics 47
     (1991) 1155-1163.

