From bolker at zoo.ufl.edu  Sat Dec 16 20:20:17 2006
From: bolker at zoo.ufl.edu (Ben Bolker)
Date: Sat, 16 Dec 2006 14:20:17 -0500
Subject: [Rd] question about trailing arguments in an S4 method
Message-ID: <458446F1.40403@zoo.ufl.edu>


  I'm trying to add arguments to the AIC method
for some classes -- things like
  weights=TRUE to calculate AIC weights
  corr=TRUE, nobs to calculate AICc
  delta=TRUE  to put a delta-AIC column in the output.

 The problem is that AIC is defined as
AIC(object, ..., k=2)  where k is the constant associated
with the penalty term and ... is a list of objects
that will have their AICs calculated and listed.
Thus I'm not allowed (I think) to extend the definition to

AIC(object, ..., nobs, corr=FALSE, delta=FALSE, weights=FALSE, k=2)

  An ugly solution to this is to go through the ... list and
pull out the values of any of the other arguments I want, and
then set them to NULL, leaving the list composed only of
additional objects to calculate the AIC for.  But it seems
really ugly ...

   Any ideas for a better way to do this would be
appreciated.  (Please be gentle if possible, I'm a bit out
of my depth with S4 ...)

  cheers
    Ben Bolker


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[Rd] question about trailing arguments in an S4 method
Ben Bolker