AIC.logLik {nlme}R Documentation

AIC of a logLik Object

Description

This function calculates the Akaike information criterion for an object inheriting from class logLik, according to the formula 2*log-likelihood + 2*npar, where npar represents the number of parameters in the fitted model. When comparing fitted objects, the smaller the AIC, the better the fit.

Usage

AIC(object)

Arguments

object an object inheriting from class logLik, usually resulting from applying a logLik method to a fitted model object.

Value

a numeric value with the corresponding AIC.

Author(s)

Jose Pinheiro and Douglas Bates

References

Sakamoto, Y., Ishiguro, M., and Kitagawa G. (1986) "Akaike Information Criterion Statistics", D. Reidel Publishing Company.

See Also

AIC, logLik, BIC

Examples

library(nlme)
data(Orthodont)
fm1 <- lm(distance ~ age, data = Orthodont) 
AIC(logLik(fm1))


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