spatstat (version 1.63-0)

logLik.slrm: Loglikelihood of Spatial Logistic Regression

Description

Computes the (maximised) loglikelihood of a fitted Spatial Logistic Regression model.

Usage

# S3 method for slrm
logLik(object, ..., adjust = TRUE)

Arguments

object

a fitted spatial logistic regression model. An object of class "slrm".

…

Ignored.

adjust

Logical value indicating whether to adjust the loglikelihood of the model to make it comparable with a point process likelihood. See Details.

Value

A numerical value.

Details

This is a method for logLik for fitted spatial logistic regression models (objects of class "slrm", usually obtained from the function slrm). It computes the log-likelihood of a fitted spatial logistic regression model.

If adjust=FALSE, the loglikelihood is computed using the standard formula for the loglikelihood of a logistic regression model for a finite set of (pixel) observations.

If adjust=TRUE then the loglikelihood is adjusted so that it is approximately comparable with the likelihood of a point process in continuous space, by subtracting the value \(n \log(a)\) where \(n\) is the number of points in the original point pattern dataset, and \(a\) is the area of one pixel.

See Also

slrm

Examples

# NOT RUN {
  X <- rpoispp(42)
  fit <- slrm(X ~ x+y)
  logLik(fit)
  logLik(fit, adjust=FALSE)
# }