R devel - Feb 2004 - minor (possibly documentation) bug in seq

With today's r-devel, help(seq) says:

     The last generates the sequence '1, 2', ...,
'length(along)',
     unless the argument is of length 1 when it is interpreted as a
     'length' argument.

referring to the usage 

     seq(along)

This is not true for 0:
> seq(0)
[1] 1 0
> seq(length = 0)
numeric(0)

I'm not sure what the intended behaviour of seq(0) is, but either seq() or
the
help page should be fixed.

Also, the exception (naturally) holds only for _numeric_ arguments of length 
1. 

Deepayan

On Wed, 4 Feb 2004, Deepayan Sarkar wrote:
> 
> With today's r-devel, help(seq) says:
> 
>      The last generates the sequence '1, 2', ...,
'length(along)',
>      unless the argument is of length 1 when it is interpreted as a
>      'length' argument.
> 
> referring to the usage 
> 
>      seq(along)
> 
> This is not true for 0:
> 
> > seq(0)
> [1] 1 0
> > seq(length = 0)
> numeric(0)
> 
> I'm not sure what the intended behaviour of seq(0) is, but either seq()
> or the help page should be fixed.
Nor am I, but it seems S documents the behaviour as 1:from, so I guess 
that is intended.
> Also, the exception (naturally) holds only for _numeric_ arguments of
length
> 1. 
I've altered the help page.

-- 
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