| Poisson {spatstat.model} | R Documentation |
Poisson Point Process Model
Description
Creates an instance of the Poisson point process model which can then be fitted to point pattern data.
Usage
Poisson()
Details
The function ppm, which fits point process models to
point pattern data, requires an argument interaction
of class "interact"
describing the interpoint interaction structure
of the model to be fitted.
The appropriate description of the Poisson process is
provided by the value of the function Poisson.
This works for all types of Poisson processes including multitype and nonstationary Poisson processes.
Value
An object of class "interact"
describing the interpoint interaction
structure of the Poisson point process
(namely, there are no interactions).
Author(s)
Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner rolfturner@posteo.net and Ege Rubak rubak@math.aau.dk
See Also
Examples
ppm(nztrees ~1, Poisson())
# fit the stationary Poisson process to 'nztrees'
# no edge correction needed
lon <- longleaf
longadult <- unmark(subset(lon, marks >= 30))
ppm(longadult ~ x, Poisson())
# fit the nonstationary Poisson process
# with intensity lambda(x,y) = exp( a + bx)
# trees marked by species
lans <- lansing
ppm(lans ~ marks, Poisson())
# fit stationary marked Poisson process
# with different intensity for each species
ppm(lansing ~ marks * polynom(x,y,3), Poisson())
# fit nonstationary marked Poisson process
# with different log-cubic trend for each species