The data record the locations of 126 pine saplings
in a Finnish forest, their heights and their diameters. The dataset finpines is a marked point pattern
containing the locations of the saplings marked by their heights
and their diameters.
Sapling locations are given in metres (to six significant digits);
heights are in metres (rounded to the nearest 0.1 metre,
except in one case to the nearest 0.05 metres);
diameters are in centimetres (rounded to the nearest centimetre).
The data were recorded by Professor Seppo Kellomaki, Faculty of
Forestry, University of Joensuu, Finland,
and subsequently massaged by Professor Antti Penttinen,
Department of Statistics, University of Jyv"askyl"a, Finland.
Originally the point locations were observed in polar coordinates with
rather poor angular precision. Hence the coordinates are imprecise for large
radius because of rounding errors: indeed the alignments can be observed by
eye.
The data were manipulated by Prof Penttinen by making small angular
perturbations at random. After this transformation, the original data
(in a circular plot) were clipped to a square window, for convenience.
Professor Penttinen emphasises that the data were intended only
for initial experimentation. They have some strange features.
For example, if the height is less than 1.3 metres then the diameter
can be uncertain. Also there are some very close pairs of points.
Some pairs of trees (namely (58,59), (78,79), (96,97) and (102,103))
violate the requirement that the interpoint distance should be
greater than half the sum of their diameters.
These data have subsequently been analysed by Van Lieshout (2004).