R: Generic Ord Interaction model

Ord {spatstat.core} | R Documentation

## 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

`pot` | An S language function giving the user-supplied interaction potential.
`name` | Character string.

### 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.

Ord (1977) proposed fitting this model to forestry data when g(a) has a simple “threshold” form. That model is implemented in our function `OrdThresh`. The present function `Ord` implements the case of a completely general Ord potential g(a) specified as an S language function `pot`.

This is experimental.

### 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 r.turner@auckland.ac.nz

### 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.

### See Also

`ppm`, `ppm.object`, `OrdThresh`

[Package spatstat.core version 2.4-4 Index]