From p.dalgaard@biostat.ku.dk  Wed Jun 17 19:41:35 1998
From: p.dalgaard@biostat.ku.dk (Peter Dalgaard BSA)
Date: 17 Jun 1998 20:41:35 +0200
Subject: extra arguments to generic functions & bug in model.frame
In-Reply-To: Jim Robison-Cox's message of Wed, 17 Jun 1998 12:22:04 -0600 (MDT)
References: <Pine.ULT.3.91.980617115505.3906G-100000@mathfs.math.montana.edu>
Message-ID: <x2g1h3oops.fsf@blueberry.kubism.ku.dk>

Jim Robison-Cox <jimrc@mathfs.math.montana.edu> writes:

> 1.  There seems to be a bug in model.frame() using terms() with 2 arguments.

Yes.

> 2.  What is standard practice for setting up instances of a generic function?
>     It seems sensible to me that argument lists should not shrink when 
>     going from the generic function to an instance of that function.

No. There's no limit to what special parameters a specific instance of
a function may implement. So the generic one is generally (x,...).
There's no reason not to allow a specific function to check that it is
getting called with parameters that make sense.

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk)             FAX: (+45) 35327907
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extra arguments to generic functions & bug in model.frame
Peter Dalgaard BSA