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Re: entropy of a binary file with conditions

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"George Johnson" <matrix29@charter.net> writes:
> "pierre" <pierre@invalid.invalid> wrote in message 
> news:4f51deb4$0$21489$ba4acef3@reader.news.orange.fr...
> > hi,
> >
> > let's suppose we have a binary file (runs of zeroes and ones) and its 
> > length is 1024 bits.
> >
> > any of these runs is not bigger than 8 (00000000 or 11111111)
> >
> > how can one compute the entropy of such a file ?
> >
> > Thank you
> 
>     Well if each 8 bit chunk is constant then the easiest thing to say is 
> that the file can be compressed to 1/8 of the original size (1024 bits / 8 = 
> 128 bits) every time.

But each 8 bits must be followed with an absolutely predictable next 8 bits.
So you can compress this situation down to almost 1 bit - the first one.

Phil
-- 
> I'd argue that there is much evidence for the existence of a God.
Pics or it didn't happen.
-- Tom (/. uid 822)

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entropy of a binary file with conditions pierre <pierre@invalid.invalid> - 2012-03-03 10:04 +0100
  Re: entropy of a binary file with conditions glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-03 09:41 +0000
    Re: entropy of a binary file with conditions pierre <pierre@invalid.invalid> - 2012-03-03 10:47 +0100
      Re: entropy of a binary file with conditions glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-03 10:00 +0000
        Re: entropy of a binary file with conditions pierre <pierre@invalid.invalid> - 2012-03-03 11:34 +0100
          Re: entropy of a binary file with conditions Alex Mizrahi <alex.mizrahi@gmail.com> - 2012-03-04 00:08 +0200
          Re: entropy of a binary file with conditions "George Johnson" <matrix29@charter.net> - 2012-03-03 22:45 -0500
            Re: entropy of a binary file with conditions "George Johnson" <matrix29@charter.net> - 2012-03-04 01:08 -0500
  Re: entropy of a binary file with conditions biject <biject.bwts@gmail.com> - 2012-03-03 12:34 -0800
    Re: entropy of a binary file with conditions glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-03 21:11 +0000
    Re: entropy of a binary file with conditions pierre <pierre@invalid.invalid> - 2012-03-04 20:57 +0100
  Re: entropy of a binary file with conditions "George Johnson" <matrix29@charter.net> - 2012-03-03 22:30 -0500
    Re: entropy of a binary file with conditions Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-03-20 18:49 +0200
  Re: entropy of a binary file with conditions James Dow Allen <jdallen2000@yahoo.com> - 2012-03-03 22:07 -0800
    Re: entropy of a binary file with conditions pierre <pierre@invalid.invalid> - 2012-03-04 20:59 +0100
  Re: entropy of a binary file with conditions Willem <willem@toad.stack.nl> - 2012-03-04 15:41 +0000
    Re: entropy of a binary file with conditions Alex Mizrahi <alex.mizrahi@gmail.com> - 2012-03-04 21:39 +0200
    Re: entropy of a binary file with conditions glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-04 22:45 +0000
      Re: entropy of a binary file with conditions Alex Mizrahi <alex.mizrahi@gmail.com> - 2012-03-05 10:03 +0200
        Re: entropy of a binary file with conditions glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-03-05 09:52 +0000
          Re: entropy of a binary file with conditions Alex Mizrahi <alex.mizrahi@gmail.com> - 2012-03-05 18:05 +0200
        Re: entropy of a binary file with conditions James Dow Allen <jdallen2000@yahoo.com> - 2012-03-05 06:03 -0800
          Re: entropy of a binary file with conditions James Dow Allen <jdallen2000@yahoo.com> - 2012-03-05 16:16 -0800
            Re: entropy of a binary file with conditions James Dow Allen <jdallen2000@yahoo.com> - 2012-03-05 16:27 -0800

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