[R] Odp: Strange behaviour of as.integer()

[Petr PIKAL]

Hi

Maybe FAQ 7.31 strikes again.

> .57 * 100==as.integer(57)
[1] FALSE
>

Regards
Petr


r-help-bounces at r-project.org napsal dne 07.01.2010 13:31:42:

> I have encountered a strange behaviour of as.integer() which does not
> seem correct to me. Sorry if this is just an indication of me not
> understanding floating point arithmetic.
> 
> > .57 * 100
> [1] 57
> > .29 * 100
> [1] 29
> 
> So far, so good. But:
> 
> > as.integer(.57 * 100)
> [1] 56
> > as.integer(.29 * 100)
> [1] 28
> 
> Then again:
> 
> > all.equal(.57 * 100, as.integer(57))
> [1] TRUE
> > all.equal(.29 * 100, as.integer(29))
> [1] TRUE
> 
> This behaviour is the same in R 2.10.1 (Ubuntu and Windows) and 2.9.2
> (Windows),
> all 32 bit versions. Is this really intended?
> 
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