## S3 method for class 'kppm':
logLik(object, ...)
## S3 method for class 'kppm':
AIC(object, \dots, k=2)
## S3 method for class 'kppm':
extractAIC(fit, scale=0, k=2, \dots)
## S3 method for class 'kppm':
nobs(object, ...)
"kppm"
.logLik
returns a numerical value, belonging to the class
"logLik"
, with an attribute "df"
giving the degrees of
freedom.
AIC
returns a numerical value. extractAIC
returns a numeric vector of length 2
containing the degrees of freedom and the AIC value.
nobs
returns an integer value.
logLik
,
extractAIC
and
nobs
for the class "kppm"
. An object of class "kppm"
represents a fitted
Cox or cluster point process model.
It is obtained from the model-fitting function kppm
.
These methods apply only when the model was fitted
by maximising the Palm likelihood (Tanaka et al, 2008)
by calling kppm
with the argument method="palm"
.
The method logLik.kppm
computes the
maximised value of the log Palm likelihood for the fitted model object
.
The methods AIC.kppm
and extractAIC.kppm
compute the
Akaike Information Criterion AIC for the fitted model
based on the Palm likelihood (Tanaka et al, 2008)
$$AIC = -2 \log(PL) + k \times \mbox{edf}$$
where $PL$ is the maximised Palm likelihood of the fitted model,
and $\mbox{edf}$ is the effective degrees of freedom
of the model.
The method nobs.kppm
returns the number of points
in the original data point pattern to which the model was fitted.
The Rfunction step
uses these methods.
kppm
,
logLik.ppm
fit <- kppm(redwood ~ x, "Thomas", method="palm")
nobs(fit)
logLik(fit)
extractAIC(fit)
AIC(fit)
step(fit)
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