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Re: Log base 2 of large integers

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From Peter Otten <__peter__@web.de>
Subject Re: Log base 2 of large integers
Date Wed, 13 Aug 2014 15:58:02 +0200
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Mok-Kong Shen wrote:
 
> I like to compute log base 2 of a fairly large integer n but
> with math.log(n,2) I got:
> 
> OverflowError: long int too large to convert to float.
> 
> Is there any feasible work-around for that?

What version of Python are you using? Python 2.7 can handle "fairly large" 
integers:

>>> float(x)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OverflowError: long int too large to convert to float
>>> math.log(x, 2)
50462500.07504181

Or maybe our idea of "fairly large" differ; so how large is fairly large?

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Thread

Log base 2 of large integers Mok-Kong Shen <mok-kong.shen@t-online.de> - 2014-08-13 15:05 +0200
  Re: Log base 2 of large integers Skip Montanaro <skip@pobox.com> - 2014-08-13 08:16 -0500
    Re: Log base 2 of large integers Mok-Kong Shen <mok-kong.shen@t-online.de> - 2014-08-13 15:50 +0200
  Re: Log base 2 of large integers Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-08-13 23:32 +1000
    Re: Log base 2 of large integers Mok-Kong Shen <mok-kong.shen@t-online.de> - 2014-08-13 15:46 +0200
      Re: Log base 2 of large integers Marko Rauhamaa <marko@pacujo.net> - 2014-08-13 17:00 +0300
      Re: Log base 2 of large integers Andrew Jaffe <a.h.jaffe@gmail.com> - 2014-08-13 15:06 +0100
    Re: Log base 2 of large integers Peter Otten <__peter__@web.de> - 2014-08-13 16:17 +0200
  Re: Log base 2 of large integers Peter Otten <__peter__@web.de> - 2014-08-13 15:58 +0200
    Re: Log base 2 of large integers Peter Pearson <ppearson@nowhere.invalid> - 2014-08-13 16:12 +0000
      Re: Log base 2 of large integers Marko Rauhamaa <marko@pacujo.net> - 2014-08-13 19:15 +0300
      Re: Log base 2 of large integers Chris Angelico <rosuav@gmail.com> - 2014-08-14 02:18 +1000
      Re: Log base 2 of large integers Ian Kelly <ian.g.kelly@gmail.com> - 2014-08-13 12:13 -0600
  Re:Log base 2 of large integers Dave Angel <davea@davea.name> - 2014-08-13 10:10 -0400

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