[Rd] Warning when indexing data.frame with FALSE

[Prof Brian Ripley]

On Mon, 31 Jul 2006, hadley wickham wrote:

> Sorry, a better example is:
> 
> > data.frame(a=1)[FALSE]
> NULL data frame with 1 rows
> > data.frame(a=1)[NULL]
> NULL data frame with 1 rows
> 
> vs
> 
> > data.frame()[FALSE]
> Warning in is.na(nm) : is.na() applied to non-(list or vector)
> NULL data frame with 0 rows
> > data.frame()[NULL]
> Warning in is.na(nm) : is.na() applied to non-(list or vector)
> NULL data frame with 0 rows

It's reasonable:

> names(data.frame())
NULL

which is a problem as data frames are supposed to have names.
So the bug is in data.frame.

-- 
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)
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