R devel - Jun 2001 - "[.data.frame" allows un-named 3rd subscript (PR#989)

Since the Extract page has usage as:

     x[i, j, ... , drop=TRUE]

I would expect that 'drop=' would need to be given to the third
'subscript'
> diag(4)[ , 4 , 4 ] # Forgot 'drop=' or added extra ','
Error in diag(4)[, 4, 4] : incorrect number of
dimensions
> 
> as.data.frame( diag(4) )[ , 4 , 4 ] # should return error, right?
[1] 0 0 0 1


Also note:
> diag(4)[ ,  , drop=TRUE ]
     [,1] [,2] [,3] [,4]
[1,]    1    0    0    0
[2,]    0    1    0    0
[3,]    0    0    1    0
[4,]    0    0    0    1
> 
> as.data.frame( diag(4) )[ ,  , drop=TRUE ]
Error in [.data.frame(as.data.frame(diag(4)), , , drop = 4) : 
	Argument "j" is missing, with no default
> 
--please do not edit the information below--

Version:
 platform = sparc-sun-solaris2.7
 arch = sparc
 os = solaris2.7
 system = sparc, solaris2.7
 status = 
 major = 1
 minor = 2.3
 year = 2001
 month = 04
 day = 26
 language = R

Search Path:
 .GlobalEnv, package:nls, package:nlme, package:ctest, Autoloads, package:base



Chuck

-- 
Charles C. Berry                        (858) 534-2098 
                                         Dept of Family/Preventive Medicine
E mailto:cberry@tajo.ucsd.edu	         UC San Diego
http://hacuna.ucsd.edu/members/ccb.html  La Jolla, San Diego 92093-0645

 

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cberry@tajo.ucsd.edu writes:
> Since the Extract page has usage as:
> 
>      x[i, j, ... , drop=TRUE]
> 
> I would expect that 'drop=' would need to be given to the third
'subscript'
> 
> > diag(4)[ , 4 , 4 ] # Forgot 'drop=' or added extra ','
> Error in diag(4)[, 4, 4] : incorrect number of dimensions
> > 
> > as.data.frame( diag(4) )[ , 4 , 4 ] # should return error, right?
> [1] 0 0 0 1
> 
And the bug is?

The generic indexing should really be x[...,drop=T].  Methods for
specific classes can specialize to a particular number of indices if
they want to, which is what is happening here
> get ("[.data.frame")
function (x, i, j, drop = if (missing(i)) TRUE else length(cols) == 
    1) 

one could fairly easily slip in a "..." argument after "j",
and then
inside the function give an error if "..." is not empty, but what
would the point be?

-- 
   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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