R devel - Apr 1999 - outer fails with group generic operations on factors (PR#166)

B <- A <- factor(c("a", "b"))
outer(A, B, "!=")
Warning: "FUN" not meaningful for factors
     [,1] [,2]
[1,]   NA   NA
[2,]   NA   NA

Now, this used to work in 0.63.2, but someone `improved' outer. There
it did an implicit as.numeric. The problem is that get in match.fun does
not understand group generics, and gets

Browse[1]> FUN
.Primitive("!=")

This _should_ launch Ops.factor, but does not.
> "!="(A, B)
[1] FALSE FALSE
> get("!=")(A, B)
Warning: "" not meaningful for factors
[1] NA NA



This causes misclass.tree(, detail=F) in package tree to fail.

--please do not edit the information below--

Version:
 platform = sparc-sun-solaris2.6
 arch = sparc
 os = solaris2.6
 system = sparc, solaris2.6
 status = 
 status.rev = 0
 major = 0
 minor = 64.0
 year = 1999
 month = April
 day = 8
 language = R

Search Path:
 .GlobalEnv, Autoloads, package:base

-- 
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 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595


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ripley@stats.ox.ac.uk writes:
> Browse[1]> FUN
> .Primitive("!=")
> 
> This _should_ launch Ops.factor, but does not.
> 
> > "!="(A, B)
> [1] FALSE FALSE
> > get("!=")(A, B)
> Warning: "" not meaningful for factors
> [1] NA NA
> 
Actually, it *does* launch Ops.factor, but it gets confused by garbage
in .Generic. The bug is this line in DispatchGroup:

    sprintf(generic, "%s", CHAR(PRINTNAME(CAR(call))));

which presumably should rather look at the "op" arg. 

I'll have a closer look.

-- 
   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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