southlancs              package:splancs              R Documentation

_C_a_n_c_e_r _c_a_s_e_s _i_n _C_h_o_r_l_e_y-_R_i_b_b_l_e

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

     Locations of cases of cancer of lung and larynx in Chorley-Ribble,
     Lancashire. The data set is split into a points object
     'southlancs.pts' and a case/control 0/1 vector 'southlancs.cc'.
     There are 917 controls and 57 cases in this data set - these
     numbers differ from 978 and 58 in Diggle (1990) and Diggle and
     Rowlingson (1994). The data set also includes the approximate
     location of an old incinerator 'old.incinerator', as well as
     'southlancs.bdy', the study area boundary.

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

     data(southlancs)

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

     A data frame with 974 observations

       [,1]  x   numeric  grid eastings (metres)
       [,2]  y   numeric  grid northings (metres)
       [,3]  cc  numeric  case/control, lung=0, larynx=1

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

     Diggle, Gatrell and Lovett, 1990, - Bailey and Gatrell 1995, ch.
     3.

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

     Bailey and Gatrell 1995, ch. 3; Diggle, P. (1990) A point process
     modelling approach to raised incidence of a rare phenomenon in the
     viscinity of a prespecified point. Journal of the Royal
     Statistical Society, A, 153, 349-362; Diggle, P. and Rowlingson,
     B. (1994) A conditional approach to point process modelling of
     elevated risk. Journal of the Royal Statistical Society, A, 157,
     433-440.

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

     data(southlancs)
     op <- par(mfrow=c(2,1))
     pointmap(southlancs.pts[southlancs.cc == 0,])
     pointmap(old.incinerator, add=TRUE, col="red", pch=19)
     title("Lung cancer controls")
     pointmap(southlancs.pts[southlancs.cc == 1,])
     pointmap(old.incinerator, add=TRUE, col="red", pch=19)
     title("Larynx cancer cases")
     par(op)
     polymap(southlancs.bdy,border="grey")
     contour(kernel2d(southlancs.pts[southlancs.cc == 0,], 
             southlancs.bdy, h=500, nx=100, ny=100), nlevels=20, 
             add=TRUE,drawlabels=FALSE)
     pointmap(southlancs.pts[southlancs.cc == 1,], add=TRUE, pch=19,
              col="green")
     pointmap(old.incinerator, add=TRUE, pch=19, col="red")
     title(xlab="h=500, quartic kernel")
     title("Density map of control, green case points, red old incinerator")

