Prof Brian Ripley
ripley at stats.ox.ac.uk
Mon Mar 31 13:39:41 MEST 2003
That's not the current version you are using, and it does work in the
However, that was caused by an additional consistency check, so I believe
it revealed a bug in the older version that we have not yet tracked down
(but have turned the check off).
On Mon, 31 Mar 2003, Roger Koenker wrote:
> I've recently updated from an early February version of 1.7.0 to
> Version 1.7.0 Under development (unstable) (2003-03-25)
> and am now having problems with errors giving the message:
> ' getExtends(ClassDef) : @ must be used on an object with a formal class'
> which seems to be caused by 'setIs("character","character or NULL")'
> which attempts to define 'character' as an extension of the virtual
> class 'character or NULL' defined in 'setClass("character or NULL")'.
> If I try this:
> > library(methods)
> > setClass("CN")
>  "CN"
> > setIs("NULL","CN")
> > setIs("numeric","CN")
> > setIs("character","CN")
> Error in getExtends(ClassDef) : @ must be used on an object with a formal class
> The fact that 'setIs("numeric","CN")' and 'setIs("NULL","CN")' work just fine
> leads me to believe that this is a bug in the new R-devel version.
Brian D. Ripley, ripley at 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 272860 (secr)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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