spatstat (version 1.13-3)

finpines: Pine saplings in Finland.

Description

The data record the locations of 126 pine saplings in a Finnish forest, their heights and their diameters.

The main dataset finpines is a marked point pattern containing the locations of the saplings marked by their heights. Additional data in finpines.extra record the sapling 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.

These data have subsequently been analysed by Van Lieshout (2004).

Usage

data(finpines)

Arguments

format

finpines is an object of class "ppp" representing the point pattern of sapling locations marked by their heights. See ppp.object for details of the format.

finpines.extra is a list with one component diameter which is a numeric vector containing the diameters of the points.

source

Prof Antti Penttinen

References

Van Lieshout, M.N.M. (2004) A J-function for marked point patterns. Research Report PNA-R0404, June 2004. Centrum voor Wiskunde en Informatica (CWI), Amsterdam, 2004.

Examples

Run this code
data(finpines)
    plot(unmark(finpines), main="Finnish pines: locations")
    plot(finpines, main="locations and heights")
    plot(finpines %mark% finpines.extra$diameter, main="diameters")

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