The link to FAQ 7.31 is
http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-think-these-numbers-are-equal_003f

Jean


On Fri, Aug 9, 2013 at 8:16 AM, jim holtman <jholtman@gmail.com> wrote:

> FAQ 7.31 is a start.
>
> Understand the "precision" of floating point numbers.  You probably only
> have about 15 digits (54 bits) of significance.
>
> If you need unlimited number of digits, there are some other alternatives.
>
>
>
> On Fri, Aug 9, 2013 at 5:54 AM, Johan Nyberg <johan@infocraft.se> wrote:
>
> > I am confused about what I believed was artefects from reading .csv files
> > with big numbers.
> > Finally I checked using the console and this is what I get, the same as
> > when importing:
> > >
> > >longnumber<-635024810560380000
> > >longnumber
> > [1] 635024810560380032
> >
> > I have tried setting "options(digits=22) and also 20 and 18 with no
> > difference. R-version is x64 3.0.1
> >
> > Does someone know or guess why this happens?
> >
> > Yours
> > Johan Nyberg, Sweden.
> >
> >
> >         [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
>
>
> --
> Jim Holtman
> Data Munger Guru
>
> What is the problem that you are trying to solve?
> Tell me what you want to do, not how you want to do it.
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

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