# Copyright 2008 Alexander W Blocker
# You are free to use, modify, and redistribute this code under the terms of the GNU
# General Public License, version 2
# Based on AIC function from  GNU R stats package, version 2.6.2

AICc <- function(x, ... , k=2) {
	UseMethod("AICc");
}

AICc.default <- function(x, ... , k=2) {
	if ( length( list( ... ) ) ) {
		x <- list( x, ... );
		val <- lapply( x, logLik );
		val <- as.data.frame( t( sapply( val, function(el) c( attr( el, 
            "df"), AICc( el, k = k) ) ) ) )
		names(val) <- c("df", "AICc")
        row.names(val) <- as.character(match.call()[-1])
        return(val)
	}
	AICc( logLik( x ) );
}

AICc.logLik <- function(x, ... , k=2) {
	-2 * c(x) + k * attr( x, "df" ) + 
		2 * attr( x, "df" ) * ( attr( x, "df" ) + 1 )/
		( attr( x, "nobs" ) - attr( x, "df" ) - 1 );
}