sphppm: Fit Model to Spherical Point Pattern
In baddstats/spherstat: Spatial Point Pattern Analysis, Geometry and Trigonometry for the Sphere

sphppm

R Documentation

Fit Model to Spherical Point Pattern

Description

Fit a parametric model for the intensity to a point pattern on a sphere or subset of the sphere.

Usage

sphppm(formula)

Arguments

formula

A formula in the R language. The left hand side should be the name of a point pattern dataset. The right hand side specifies the form of the intensity.

Details

This is analogous to the spatstat function ppm.

The argument formula should be a formula in the R language. The left hand side should be the name of a point pattern dataset, which should belong to one of the classes sp2 or sp3. The right hand side of the formula may involve any of the variables theta (colatitude), phi (longitude) and x1, x2, x3 representing three-dimensional spatial location.

The model is fitted by the logistic regression algorithm of Baddeley et al (2014). This procedure uses a random pattern of dummy points, so the fitted model coefficients may change slightly if the model is re-fitted.

Value

An object of class sphppm. See methods.sphppm for available methods.

Author(s)

Adrian Baddeley.

References

Baddeley, A. and Coeurjolly, J.-F. and Rubak, E. and Waagepetersen, R. (2014) Logistic regression for spatial Gibbs point processes. Biometrika 101, 377–392.

Examples

   W <- sphwin(type="band", param=c(pi/3, 2*pi/3), ref=c(0,0))
   Z <- runif.sphwin(100, W)
   sphppm(Z ~ 1)
   sphppm(Z ~ cos(theta) + cos(phi))
   sphppm(Z ~ abs(x1))

baddstats/spherstat documentation built on Feb. 6, 2023, 1:45 a.m.