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.

data(southlancs)

Format

A data frame with 974 observations

[,1]xnumericgrid eastings (metres)
[,2]ynumericgrid northings (metres)
[,3]ccnumericcase/control, lung=0, larynx=1

Source

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

References

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.

Examples

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)
#> Xrange is  343709.1 366255.6 
#> Yrange is  410927.2 429344.1 
#> Doing quartic kernel
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")