[Rd] How to handle INT8 data

[Murray Stokely]

2^53 == 2^53+1
TRUE

Which makes joining or grouping data sets with 64 bit identifiers
problematic.

Murray (mobile)

On Jan 20, 2017 9:15 AM, "Nicolas Paris" <nicolas.paris at aphp.fr> wrote:

Le 20 janv. 2017 à 18h09, Murray Stokely écrivait :
> The lack of 64 bit integer support causes lots of problems when dealing
with
> certain types of data where the loss of precision from coercing to 53
bits with
> double is unacceptable.

Hello Murray,
Do you mean, by eg. -1311071933951566764 loses in precision during
as.numeric(-1311071933951566764) process ?
Thanks,
>
> Two packages were developed to deal with this:  int64 and bit64.
>
> You may need to find archival versions of these packages if they've
fallen off
> cran.
>
> Murray (mobile phone)
>
> On Jan 20, 2017 7:20 AM, "Gabriel Becker" <gmbecker at ucdavis.edu> wrote:
>
>     I am not on R-core, so cannot speak to future plans to internally
support
>     int8 (though my impression is that there aren't any, at least none
that are
>     close to fruition).
>
>     The standard way of dealing with whole numbers too big to fit in an
integer
>     is to put them in a numeric (double down in C land). this can
represent
>     integers up to 2^53 without loss of precision see (
>     http://stackoverflow.com/questions/1848700/biggest-
>     integer-that-can-be-stored-in-a-double).
>     This is how long vector indices are (currently) implemented in R. If
it's
>     good enough for indices it's probably good enough for whatever you
need
>     them for.
>
>     Hope that helps.
>
>     ~G
>
>
>     On Fri, Jan 20, 2017 at 6:33 AM, Nicolas Paris <nicolas.paris at aphp.fr>
>     wrote:
>
>     > Hello r users,
>     >
>     > I have to deal with int8 data with R. AFAIK  R does only handle int4
>     > with `as.integer` function [1]. I wonder:
>     > 1. what is the better approach to handle int8 ? `as.character` ?
>     > `as.numeric` ?
>     > 2. is there any plan to handle int8 in the future ? As you might
know,
>     > int4 is to small to deal with earth population right now.
>     >
>     > Thanks for you ideas,
>     >
>     > int8 eg:
>     >
>     >      human_id
>     > ----------------------
>     >  -1311071933951566764
>     >  -4708675461424073238
>     >  -6865005668390999818
>     >   5578000650960353108
>     >  -3219674686933841021
>     >  -6469229889308771589
>     >   -606871692563545028
>     >  -8199987422425699249
>     >   -463287495999648233
>     >   7675955260644241951
>     >
>     > reference:
>     > 1. https://www.r-bloggers.com/r-in-a-64-bit-world/
>     >
>     > --
>     > Nicolas PARIS
>     >
>     > ______________________________________________
>     > R-devel at r-project.org mailing list
>     > https://stat.ethz.ch/mailman/listinfo/r-devel
>     >
>
>
>
>     --
>     Gabriel Becker, PhD
>     Associate Scientist (Bioinformatics)
>     Genentech Research
>
>             [[alternative HTML version deleted]]
>
>     ______________________________________________
>     R-devel at r-project.org mailing list
>     https://stat.ethz.ch/mailman/listinfo/r-devel
>
>

--
Nicolas PARIS

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