Many thankis, Gabor! That looks both interesting and powerful.
Indeed, it seems to implement with one stroke what I had been
thinking of implementing piecemeal.
Best wishes,
Ted.
On 17-May-09 17:48:00, Gabor Grothendieck wrote:
> gsubfn of the gsubfn package is like gsub but can take a function,
> list or proto object as the replacement instead of a character
> string and with a list it can be used to readily turn hex to binary:
>
>> library(gsubfn)
>> binary.digits <-
> + list("0"= "0000", "1"= "0001", "2"= "0010", "3"= "0011",
> + "4"= "0100", "5"= "0101", "6"= "0110", "7"= "0111",
> + "8"= "1000", "9"= "1001", "A"= "1010", "B"= "1011",
> + "C"= "1100", "D"= "1101", "E"= "1110", "F"= "1111")
>>
>> gsubfn("[0-9A-F]", binary.digits, "0X1.921FB54442D18P+1")
> [1]
> "0000X0001.1001001000011111101101010100010001000010110100011000P+0001"
>
>
> On Sun, May 17, 2009 at 1:23 PM, Ted Harding
> <ted.hard...@manchester.ac.uk> wrote:
>> I am interested in studying the binary representation of numerics
>> (doubles) in R, so am looking for possibilities of output of the
>> internal binary representations. sprintf() with format "a" or "A"
>> is halfway there:
>>
>> _sprintf("%A",pi)
>> # [1] "0X1.921FB54442D18P+1"
>>
>> but it is in hex.
>>
>> The following illustrate the sort of thing I want:
>>
>> 1.1001 0010 0001 1111 1011 0101 0100 0100 0100 0010 1101 0001 1000
>> times 2
>>
>> 11.0010 0100 0011 1111 0110 1010 1000 1000 1000 0101 1010 0011 000
>>
>> 0.1100 1001 0000 1111 1101 1010 1010 0010 0010 0001 0110 1000 1100 0
>> times 4
>>
>> (without the spaces -- only put in above for clarity).
>>
>> While I could take the original output "0X1.921FB54442D18P+1" from
>> sprintf() and parse it out into binary using gsub() or the like,
>> of submit it to say an 'awk' script via an external file, this would
>> be a tedious business!
>>
>> Is there some function already in R which outputs the bits in the
>> binary representation directly?
>>
>> I see that Dabid Hinds asked a similar question on 17 Aug 2005:
>> "Raw data type transformations"
>>
>> _http://finzi.psych.upenn.edu/R/Rhelp02/archive/59900.html
>>
>> (without, apparently, getting any response -- at any rate within
>> the following 3 months).
>>
>> With thanks for any suggestions,
>> Ted.
>>
>> --------------------------------------------------------------------
>> E-Mail: (Ted Harding) <ted.hard...@manchester.ac.uk>
>> Fax-to-email: +44 (0)870 094 0861
>> Date: 17-May-09 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Time: 18:23:49
>> ------------------------------ XFMail ------------------------------
>>
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>> PLEASE do read the posting guide
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>> and provide commented, minimal, self-contained, reproducible code.
>>
>
> ______________________________________________
> R-help@r-project.org mailing list
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> PLEASE do read the posting guide
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--------------------------------------------------------------------
E-Mail: (Ted Harding) <ted.hard...@manchester.ac.uk>
Fax-to-email: +44 (0)870 094 0861
Date: 17-May-09 Time: 21:09:12
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