From ripley at stats.ox.ac.uk  Thu Sep  3 13:30:27 2009
From: ripley at stats.ox.ac.uk (ripley at stats.ox.ac.uk)
Date: Thu,  3 Sep 2009 13:30:27 +0200 (CEST)
Subject: [Rd] names<- in data.frame (PR#13916)
Message-ID: <20090903113027.EE5692832011@mail.pubhealth.ku.dk>

It does work correctly:

> names(tdf)
[1] "" ""

The thing you have overlooked is that data frames are required to have 
non-empty (not 'zero-length': yours has length 2) names, and the print 
method has created some (as data.frame will if you give unnamed 
arguments).

Please be careful to distinguish between an object and its printed 
representation.

On Fri, 28 Aug 2009, vitosmail at rambler.ru wrote:

> Full_Name: Spinu Vitalie
> Version: 2.9.0
> OS: Windows
> Submission from: (NULL) (130.115.113.15)
>
>
> In assignment of "zero length" names to data.frame:
>
>> tdf <- data.frame(rbind(c(1, 2), c(1, 2)))
>> names(tdf) <- c("", "")
>> tdf
>  structure(c("1", "1"), class = "AsIs") structure(c("2", "2"), class = "AsIs")
> 1                                      1                                      2
> 2                                      1                                      2
>
> For vectors it works nicely:
>
>> tv <- c(1, 2)
>> names(tv) <- c("", "")
>> tv
>
> 1 2
>
>
>
>
>> sessionInfo()
> R version 2.9.0 (2009-04-17)
> i386-pc-mingw32
>
> locale:
> LC_COLLATE=English_United States.1252;LC_CTYPE=English_United
> States.1252;LC_MONETARY=English_United
> States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252
>
> attached base packages:
> [1] stats     graphics  uti
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>

-- 
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 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595



[Rd] names<- in data.frame (PR#13916)
ripley at stats.ox.ac.uk