[Rd] Critical Bug in type conversions: as.integer, trunc, ... (PR#8255)
Duncan Murdoch
murdoch at stats.uwo.ca
Thu Oct 27 15:40:05 CEST 2005
On 10/27/2005 9:24 AM, g.toedt at dkfz.de wrote:
> Full_Name: Grischa Tödt
> Version: 2.1.1
> OS: windows XP
> Submission from: (NULL) (192.108.25.32)
>
>
> I have a strange behaviour in R, looks like type conversions are messed up.
This is not a bug, it's normal behaviour for floating point values,
discussed in the FAQ item on "7.31 Why doesn't R think these numbers are
equal?"
Duncan Murdoch
>
> To reproduce:
>
> expected:
>> typeof(3)
> [1] "double"
>
>> as.integer(3)
> [1] 3
>
> !!!! strange:
>> typeof((0.3/0.1))
> [1] "double"
>
>> as.integer((0.3/0.1))
> [1] 2
>
> also for trunc:
>>trunc(c(5,7))
>>c(0.5,0.7)/c(0.1,0.1)
>
> and now watch the amazing!!!!:
>>trunc((c(0.5,0.7)/c(0.1,0.1)))
>
>
>
>
> My R-Version:
> platform i386-pc-mingw32
> arch i386
> os mingw32
> system i386, mingw32
> status
> major 2
> minor 1.1
> year 2005
> month 06
> day 20
> language R
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
More information about the R-devel
mailing list