spatstat (version 1.46-1)

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".
...
Additional arguments passed to deviance.ppm or deviance.lppm.

Value

A single numeric value.

Details

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.

See Also

deviance.ppm, deviance.lppm.

Examples

Run this code
  fit <- ppm(swedishpines ~ x+y)
  pseudoR2(fit)

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