spatstat.data (version 3.1-9)

longleaf: Longleaf Pines Point Pattern

Description

Locations and sizes of Longleaf pine trees. A marked point pattern.

The data record the locations and diameters of 584 Longleaf pine (Pinus palustris) trees in a 200 x 200 metre region in southern Georgia (USA). They were collected and analysed by Platt, Evans and Rathbun (1988).

This is a marked point pattern; the mark associated with a tree is its diameter at breast height (dbh), a convenient measure of its size. Several analyses have considered only the ``adult'' trees which are conventionally defined as those trees with dbh greater than or equal to 30 cm.

The pattern is regarded as spatially inhomogeneous.

Usage

data(longleaf)

Format

An object of class "ppp" representing the point pattern of tree locations. Entries include

x	Cartesian \(x\)-coordinate of tree in metres
y	Cartesian \(y\)-coordinate of tree in metres
marks	diameter at breast height, in centimetres.

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

References

Platt, W. J., Evans, G. W. and Rathbun, S. L. (1988) The population dynamics of a long-lived Conifer (Pinus palustris). The American Naturalist 131, 491--525.

Rathbun, S. L. and Cressie, N. (1994) A space-time survival point process for a longleaf pine forest in southern Georgia. Journal of the American Statistical Association 89, 1164--1173.

Examples

    data(longleaf)
  if(require(spatstat.geom)) {
    plot(longleaf)
    plot(cut(longleaf, breaks=c(0,30,Inf), labels=c("Sapling","Adult")))
  }