These data are used as a standard example in the textbook of Diggle (2003); see pages 1, 14, 19, 22, 24, 56--57 and 61.
data(japanesepines)
"ppp"
representing the point pattern of tree locations
in a 5.7 x 5.7 metre square, rescaled to the unit square
and rounded to two decimal places. See ppp.object
for details of the format of a
point pattern object.
Numata, M. (1961) Forest vegetation in the vicinity of Choshi. Coastal flora and vegetation at Choshi, Chiba Prefecture. IV. Bulletin of Choshi Marine Laboratory, Chiba University 3, 28--48 (in Japanese).