pseudoR2:
Calculate Pseudo-R-Squared for Point Process Model
Description
Given a fitted point process model, calculate
the pseudo-R-squared value, which measures the
fraction of variation in the data that is explained
by the model.
Usage
pseudoR2(object, ...)
"pseudoR2"(object, ...)
"pseudoR2"(object, ...)
Arguments
object
Fitted point process model. An object of class "ppm"
or "lppm".
The function pseudoR2 is generic, with methods
for fitted point process models of class "ppm" and
"lppm".
This function computes McFadden's pseudo-Rsquared
$$
R^2 = 1 - \frac{D}{D_0}
$$
where $D$ is the deviance of the fitted model object,
and $D0$ is the deviance of the null model
(obtained by refitting object
using the trend formula ~1).
Deviance is defined as twice the negative log-likelihood
or log-pseudolikelihood.