[R] integer

[Göran Broström]

On Tue, Nov 02, 2004 at 11:36:27AM +0100, Uwe Ligges wrote:
> Ludovic Tambour wrote:
> 
> >Hello,
> >
> >I need to use "R" to determine parameters which are integers. How I can do
> >this, please ?
> 
> What so you mean with "parameters"? In which context?
> 
> To check whether a numeric vector "x" contains only integers, you can try
> 
> all.equal(as.integer(x), x)

I don't think so:

> x <- as.double(c(1, 2))
> y <- as.integer(c(1, 2))
> all.equal(x, y)
[1] TRUE

But,

> identical(x, y)
[1] FALSE

On the other hand, why not use 

> is.integer(x)
[1] FALSE
> is.integer(y)
[1] TRUE

because I think that a numeric vector can't have a mix of integer and
non-integer elements. With a list it's a different story.

Göran
-- 
 Göran Broström                    tel: +46 90 786 5223
 Department of Statistics          fax: +46 90 786 6614
 Umeå University                   http://www.stat.umu.se/egna/gb/
 SE-90187 Umeå, Sweden             e-mail: gb at stat.umu.se