California Redwoods Point Pattern (Ripley's Subset)
Locations of 62 seedlings and saplings of California redwood trees.
The data represent the locations of 62 seedlings and saplings of California redwood trees in a square sampling region. They originate from Strauss (1975); the present data are a subset extracted by Ripley (1977) in a subregion that has been rescaled to a unit square.
Two versions of this dataset are provided:
redwood was obtained from the spatial package.
In this version the coordinates are given to 2 decimal places
(multiples of 0.01 units) except for one point which has an \(x\) coordinate
of 0.999, presumably to ensure that it is properly inside the window.
redwood3 was obtained from Peter Diggle's webpage.
In this version the coordinates are given to 3 decimal places
(multiples of 0.001 units). The ordering of the points is not the same
in the two datasets.
There are many further analyses of this dataset. It is often used as a canonical example of a clustered point pattern (see e.g. Diggle, 1983).
The original, full redwood dataset is supplied in the
An object of class
representing the point pattern of tree locations.
The window has been rescaled to the unit square.
ppp.object for details of the format of a
point pattern object.
Diggle, P.J. (1983) Statistical analysis of spatial point patterns. Academic Press.
Ripley, B.D. (1977) Modelling spatial patterns (with discussion). Journal of the Royal Statistical Society, Series B 39, 172--212.
Strauss, D.J. (1975) A model for clustering. Biometrika 62, 467--475.