https://github.com/cran/spatstat
Tip revision: edc49ab1e55bf5475be2f4d0987c835f45800ebc authored by Adrian Baddeley on 08 October 2015, 13:43:38 UTC
version 1.43-0
version 1.43-0
Tip revision: edc49ab
Ord.Rd
\name{Ord}
\alias{Ord}
\title{Generic Ord Interaction model}
\description{
Creates an instance of an Ord-type interaction point process model
which can then be fitted to point pattern data.
}
\usage{
Ord(pot, name)
}
\arguments{
\item{pot}{An S language function giving the user-supplied
interaction potential.}
\item{name}{Character string.}
}
\value{
An object of class \code{"interact"}
describing the interpoint interaction
structure of a point process.
}
\details{
Ord's point process model (Ord, 1977) is a Gibbs point process
of infinite order. Each point \eqn{x_i}{x[i]} in the point pattern
\eqn{x} contributes a factor \eqn{g(a_i)}{g(a[i])} where
\eqn{a_i = a(x_i, x)}{a[i] = a(x[i], x)} is the area of the
tile associated with \eqn{x_i}{x[i]}
in the Dirichlet tessellation of \eqn{x}.
Ord (1977) proposed fitting this model to forestry data
when \eqn{g(a)} has a simple ``threshold'' form. That model is
implemented in our function \code{\link{OrdThresh}}.
The present function \code{Ord} implements the case of a
completely general Ord potential \eqn{g(a)}
specified as an S language function \code{pot}.
This is experimental.
}
\references{
Baddeley, A. and Turner, R. (2000)
Practical maximum pseudolikelihood for spatial point patterns.
\emph{Australian and New Zealand Journal of Statistics}
\bold{42}, 283--322.
Ord, J.K. (1977)
Contribution to the discussion of Ripley (1977).
Ord, J.K. (1978)
How many trees in a forest?
\emph{Mathematical Scientist} \bold{3}, 23--33.
Ripley, B.D. (1977)
Modelling spatial patterns (with discussion).
\emph{Journal of the Royal Statistical Society, Series B},
\bold{39}, 172 -- 212.
}
\seealso{
\code{\link{ppm}},
\code{\link{ppm.object}},
\code{\link{OrdThresh}}
}
\author{Adrian Baddeley
\email{Adrian.Baddeley@uwa.edu.au}
\url{http://www.maths.uwa.edu.au/~adrian/}
and Rolf Turner
\email{r.turner@auckland.ac.nz}
}
\keyword{spatial}
\keyword{models}