New Zealand Trees Point Pattern

Description

The data give the locations of trees in a forest plot.

They were collected by Mark and Esler (1970) and were extracted and analysed by Ripley (1981, pp. 169-175). They represent the positions of 86 trees in a forest plot approximately 140 by 85 feet.

Ripley discarded from his analysis the eight trees at the right-hand edge of the plot (which appear to be part of a planted border) and trimmed the window by a 5-foot margin accordingly.

Usage

data(nztrees)

Format

An object of class "ppp" representing the point pattern of tree locations. The Cartesian coordinates are in feet.

See ppp.object for details of the format of a point pattern object.

Note

To trim a 5-foot margin off the window, type nzsub <- nztrees[ , owin(c(0,148),c(0,95)) ]

Source

Mark and Esler (1970), Ripley (1981).

References

Ripley, B.D. (1981) Spatial statistics. John Wiley and Sons.

Mark, A.F. and Esler, A.E. (1970) An assessment of the point-centred quarter method of plotless sampling in some New Zealand forests. Proceedings of the New Zealand Ecological Society 17, 106–110.