| logLik.gam {mgcv} | R Documentation |
Function to extract the log-likelihood for a fitted gam
model (note that the models are usually fitted by penalized likelihood maximization).
logLik.gam(object,...)
object |
fitted model objects of class gam as produced by gam(). |
... |
un-used in this case |
Modification of logLik.glm which corrects the degrees of
freedom for use with gam objects.
The function is provided so that AIC functions correctly with
gam objects, and uses the appropriate degrees of freedom (accounting
for penalization). Note, when using AIC for penalized models, that the
degrees of freedom are the effective degrees of freedom and not the number of
parameters, and the model maximizes the penalized likelihood, not the actual likelihood!
Standard logLik object: see logLik.
Note that the likelihood is evaluated at the maximum of the penalized likelihood for most GAMs, rather than at the MLE.
Simon N. Wood simon@stats.gla.ac.uk based directly on logLik.glm