Computes Akaike difference and Akaike weights from an object of formal class “aic”.
Usage
## S4 method for signature 'aic'
summary(object, which = c("AIC", "AICc"))
Arguments
object
An object of formal class “aic”.
which
A character string indicating which information criterion is selected to compute Akaike difference and
Akaike weights: either “AIC” or “AICc”.
Methods
summary
The models are ordered according to AIC or AICc and 3 statistics are computed:
- the Akaike differenceΔ: the change in AIC (or AICc) between successive (ordered) models,
- the Akaike weightW: when r models are compared,
W = exp(-0.5 * Δ) / sum(exp(-0.5 * Δ)),
- the cumulative Akaike weightcum.W: the Akaike weights sum to 1 for the r models which
are compared.
References
Burnham, K.P., Anderson, D.R., 2002. Model selection and multimodel inference: a practical
information-theoretic approach. New-York, Springer-Verlag, 496 p.
Hurvich, C.M., Tsai, C.-L., 1995. Model selection for extended quasi-likelihood models in small samples.
Biometrics, 51 (3): 1077-1084.