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=T, col="red", pch=19)
     title("Lung cancer controls")
     pointmap(southlancs.pts[southlancs.cc == 1,])
     pointmap(old.incinerator, add=T, 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=T,drawlabels=F)
     pointmap(southlancs.pts[southlancs.cc == 1,], add=T, pch=19,
              col="green")
     pointmap(old.incinerator, add=T, pch=19, col="red")
     title(xlab="h=500, quartic kernel")
     title("Density map of control, green case points, red old incinerator")

