[R] surprising difference in log()

[Mike Lawrence]

According to the description of floor(), the latter result is the  
correct one:

'floor takes a single numeric argument x and returns a numeric vector  
containing the largest integers *not greater than* the corresponding  
elements of x.' (emphasis added)

floor(3) == 2
 >True


On 26-Jun-07, at 11:09 AM, Fausto Galli wrote:

>
> Hello everybody
>
> My collegue and I noticed a strange behaviour of R on different
> platforms. It's a simple computation, but results are rather  
> different.
>
> On Windows XP:
>
>> floor(log(8,2))
> [1] 3
>
> which is what one should expect.
> Here's instead the result with Mac OS X (same version, 2.5.0
> (2007-04-23))
>
>> floor(log(8,2))
> [1] 2
>
> Is it a "bug" in R or in the operating system?
> Anyway, it's quite a surprising one.
>
>
>
>
>
> _____________________________________
> Fausto Galli
> Institute of Finance
> University of Lugano
> Via G. Buffi 13
> CH-6904 Lugano, Switzerland.
> +41 (0)58 666 4497
> http://www.people.lu.unisi.ch/gallif
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting- 
> guide.html
> and provide commented, minimal, self-contained, reproducible code.

--
Mike Lawrence
Graduate Student, Department of Psychology, Dalhousie University

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