From ripley at stats.ox.ac.uk  Tue Apr 20 17:13:55 2004
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Tue Apr 20 17:14:00 2004
Subject: [Rd] Re: [R] Unexpected behaviour of identical (PR#6799)
In-Reply-To: <6.1.0.6.2.20040420090025.03fcf3e0@mailhost.blackmesacapital.com>
Message-ID: <Pine.LNX.4.44.0404201613020.14900-100000@gannet.stats>

I wondered that, but I think we need to hear from the author of 
identical().

It is neater to have attributes printed in a consistent order, though.

On Tue, 20 Apr 2004, Tony Plate wrote:

> What about changing identical() to ignore the order of attributes?  Is 
> there any code anywhere that depends on the order of attributes, other than 
> identical()?  I've only seen attributes treated as an unordered set, and 
> never as an ordered list.  There are some functions in S-plus that change 
> the order of attributes, and the only thing this affects is 
> identical().  (Which in S-plus also pays attention to the order of attributes.)
> 
> -- Tony Plate
> 
> At Tuesday 05:42 AM 4/20/2004, p.dalgaard@biostat.ku.dk wrote:
> >"Swinton, Jonathan" <Jonathan.Swinton@astrazeneca.com> writes:
> >
> > >  # works as expected
> > > > ac <- c('A','B');
> > > > identical(ac,ac[1:2])
> > > [1] TRUE
> > >
> > >  #but
> > > > af <- factor(ac)
> > > > identical(af,af[1:2])
> > > [1] FALSE
> > >
> > > Any opinions?
> >
> >Did a cross-check with Splus and it doesn't do that , so I think it
> >qualifies as a bug. Shouldn't be too hard to fix (might lose a little
> >efficiencty though).
> >
> >--
> >    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
> >
> >______________________________________________
> >R-devel@stat.math.ethz.ch mailing list
> >https://www.stat.math.ethz.ch/mailman/listinfo/r-devel
> 
> ______________________________________________
> R-devel@stat.math.ethz.ch mailing list
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> 
> 

-- 
Brian D. Ripley,                  ripley@stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595


[Rd] Re: [R] Unexpected behaviour of identical (PR#6799)
Prof Brian Ripley