[Rd] How to handle INT8 data
Nicolas Paris
nicolas.paris at aphp.fr
Fri Jan 20 19:05:31 CET 2017
Hi,
I do have < INT_MAX.
This looks attractive but since they are unique identifiers, storing
them as factor will be likely to be counter-productive. (a string
version + an int32 for each)
I was looking to https://cran.r-project.org/web/packages/csvread/index.html
This looks like a good feet for my needs.
Any chances such an external package for int64 would be integrated in core ?
Le 20 janv. 2017 à 18h57, Gabriel Becker écrivait :
> How many unique idenfiiers do you have?
>
> If they are large (in terms of bytes) but you don't have that many of them (eg
> the total possible number you'll ever have is < INT_MAX), you could store them
> as factors. You get the speed of integers but the labeling of full "precision"
> strings. Factors are fast for joins.
>
> ~G
>
> On Fri, Jan 20, 2017 at 9:47 AM, Nicolas Paris <nicolas.paris at aphp.fr> wrote:
>
> Well I definitely cannot use them as numeric because join is the main
> reason of those identifiers.
>
> About int64 and bit64 packages, it's not a solution, because I am
> releasing a dataset for external users. I cannot ask them to install a
> package in order to exploit them.
>
> I have to be very carefull when releasing the data. If a user just use
> read.csv functions, they by default cast the identifiers as numeric.
>
> $ more res.csv
> "col1";"col2"
> "-1311071933951566764";"toto"
> "-1311071933951566764";"tata"
>
>
> > read.table("res.csv",sep=";",header=T)
> col1 col2
> 1 -1.311072e+18 toto
> 2 -1.311072e+18 tata
>
> >sapply(read.table("res.csv",sep=";",header=T),class)
> col1 col2
> "numeric" "factor"
>
> > read.table("res.csv",sep=";",header=T,colClasses="character")
> col1 col2
> 1 -1311071933951566764 toto
> 2 -1311071933951566764 tata
>
> Am I comdemned to provide a R script with the data in order to exploit the
> dataset ?
>
> Le 20 janv. 2017 à 18h29, Murray Stokely écrivait :
> > 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
> >
> >
>
> --
> Nicolas PARIS
>
>
>
>
> --
> Gabriel Becker, PhD
> Associate Scientist (Bioinformatics)
> Genentech Research
--
Nicolas PARIS
Responsable R & D
WIND - PACTE, Hôpital Rothschild ( RTH )
Courriel : nicolas.paris at aphp.fr
Tel : 01 48 04 21 07
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