[R] problem with extractAIC()

[Jordi Moya]

    Dear friends,
   If I use:
   model<-lm(y ~ x)
   and then extractAIC(model), the value that I obtain does not match (not even
   close):
   AIC=2*k-2*logLik(model)
   However, using AIC from the AICcmodavg(), the value matches exactly the
   above value.
   I read the help of extractAIC() and could not figure out what was wrong,
   other than what I call k (number of parameters) is edf in the help and k
   they use for the value 2 that multiplies my k, their edf, and which is
   implemeted  as  the  default, thus not possibly being the cause of the
   missmatch.
   Does anybody know whether am I missing something or whether there may be a
   bug in extractAIC()?
   Best wishes,
   Jordi Moya-Laraño
   Cantabrian Institute of Biodiversity (ICAB)
   Dpto. Biología de Organismos y Sistemas
   Universidad de Oviedo
   Catedrático Rodrigo Uría s/n
   33006-Oviedo
   Asturias
   Spain
   [1]http://www.uniovi.es/icab/jordi.html

References

   1. http://www.uniovi.es/icab/jordi.html