| OrdThresh {spatstat.model} | R Documentation |
Ord's Interaction model
Description
Creates an instance of Ord's point process model which can then be fitted to point pattern data.
Usage
OrdThresh(r)
Arguments
r |
Positive number giving the threshold value for Ord's model. |
Details
Ord's point process model (Ord, 1977) is a Gibbs point process
of infinite order. Each point x_i in the point pattern
x contributes a factor g(a_i) where
a_i = a(x_i, x) is the area of the
tile associated with x_i
in the Dirichlet tessellation of x. The function g is
simply g(a) = 1 if a \ge r and
g(a) = \gamma < 1 if a < r,
where r is called the threshold value.
This function creates an instance of Ord's model with a given
value of r. It can then be fitted to point process data
using ppm.
Value
An object of class "interact"
describing the interpoint interaction
structure of a point process.
Author(s)
Adrian Baddeley Adrian.Baddeley@curtin.edu.au
and Rolf Turner rolfturner@posteo.net
References
Baddeley, A. and Turner, R. (2000) Practical maximum pseudolikelihood for spatial point patterns. Australian and New Zealand Journal of Statistics 42, 283–322.
Ord, J.K. (1977) Contribution to the discussion of Ripley (1977).
Ord, J.K. (1978) How many trees in a forest? Mathematical Scientist 3, 23–33.
Ripley, B.D. (1977) Modelling spatial patterns (with discussion). Journal of the Royal Statistical Society, Series B, 39, 172 – 212.