The file "heather" contains a binary representation of 
   the presence/absence (1/0) of heather in a 10metre by
   20metre rectangle, digitised to a 256 by 512 array. The
   file is arranged with 32 entries per line, corresponding
   to a row-wise scan of the ground-truth 256 by 512 array.

   To read the data into R and obtain a binary image,
   you can use the following commands (amongst many other
   possiblities):
      data_matrix(scan("heather"),nrow=256,ncol=512,byrow=T)
      X11() # or whatever graphics device you prefer
      par(pty="s")
      image(t(data),xlim=c(0,512),ylim=c(0,512))

   The resulting image should correspond to the picture of
   the data shown in Diggle (1981, Biometrics, 37, 531-9),
   which used a slightly different resolution.
      
   The data were collected in central Sweden by Goran Agren,
   Toby Fagerstrom and Peter Diggle, in September 1978. Their
   representation as a 256 by 512 binary array was constructed
   so eyears later by Adrian Baddelely