[R] convert large integers to hex

[Gabor Grothendieck]

There is an interface between R and bc -- not on CRAN but available
from its home page here:
http://r-bc.googlecode.com

> source("http://r-bc.googlecode.com/svn/trunk/R/bc.R")
> bc("obase = 16; 123456789123456789", retclass = "character")
[1] "1B69B4BACD05F15"


On Wed, May 6, 2009 at 9:59 PM, jim holtman <jholtman at gmail.com> wrote:
> You can use the 'bc' command (use Cygwin if on Windows);
>
> /cygdrive/c: bc
> bc 1.06
> Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc.
> This is free software with ABSOLUTELY NO WARRANTY.
> For details type `warranty'.
> x=6595137340052185552
> obase=16
> x
> 5B86A277DEB9A1D0
>
> You can call this from R.
>
> On Wed, May 6, 2009 at 3:26 PM, Sundar Dorai-Raj <sdorairaj at gmail.com>wrote:
>
>> Hi,
>>
>> I'm wondering if someone has solved the problem of converting very
>> large integers to hex. I know about format.hexmode and as.hexmode, but
>> these rely on integers. The numbers I'm working with are overflowing
>> and losing precision. Here's an example:
>>
>> x <- "6595137340052185552" # stored as character
>> as.integer(x) # warning about inaccurate conversion
>> format.hexmode(as.numeric(x)) # warnings about loss of precision
>> as.hexmode(x) # more warnings and does not do what I expected
>>
>> I'm planning on writing a function that will do this, but would like
>> to know if anybody already has a solution. Basically, I would like the
>> functionality of format.hexmode on arbitrarily large integers.
>>
>> Thanks,
>>
>> --sundar
>>
>> ______________________________________________
>> R-help at 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<http://www.r-project.org/posting-guide.html>
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>
>
> --
> Jim Holtman
> Cincinnati, OH
> +1 513 646 9390
>
> What is the problem that you are trying to solve?
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at 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.
>