| logLik.slrm {spatstat.model} | R Documentation |
Loglikelihood of Spatial Logistic Regression
Description
Computes the (maximised) loglikelihood of a fitted Spatial Logistic Regression model.
Usage
## S3 method for class 'slrm'
logLik(object, ..., adjust = TRUE)
Arguments
object |
a fitted spatial logistic regression model.
An object of class |
... |
Ignored. |
adjust |
Logical value indicating whether to adjust the loglikelihood of the model to make it comparable with a point process likelihood. See Details. |
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.
Value
A numerical value.
Author(s)
Adrian Baddeley Adrian.Baddeley@curtin.edu.au and Rolf Turner rolfturner@posteo.net.
See Also
Examples
X <- rpoispp(42)
fit <- slrm(X ~ x+y)
logLik(fit)
logLik(fit, adjust=FALSE)