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Re: compressable data

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<malcolm.mclean5@btinternet.com> wrote:

> On Tuesday, July 9, 2013 7:33:52 PM UTC+1, osmium wrote:
>> <malcolm.mclean5@btinternet.com> wrote
>>
>> On the OPs question, I have to insert words into the question in order 
>> for
>> it to have any meaning to me. Generate data.  Generate *real* data?  What 
>> is
>> data?  Is a journal article on some obscure branch of medicine or 
>> chemistry
>> data?  Is rap music data?  By changing the definition of data, I change 
>> the
>> compression ratio.  But the OP, as I read it, wants it to be constant.  I
>> sense a problem.
>>
> With real data, it's very hard to define the entropy. But with random 
> data,
> non-randomised by some rule, it can be relatively easy. So data which 
> consisted
> of a discretised normal Markov model (so character i + 1 = character[i] + 
> (int) randgauss(), with wrap ) has a known entropy, and can be ideally 
> compressed
> with a predictive algorithm with a single byte of state.

It looks like we disagree on what the meaning of "data" is; to me, data has 
meaning.  What I see you discussing is random bits. If there is no means of 
converting bits to something else, (by talking to a programmer, for example) 
it is just bits - no meaning - no data. 

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compressable data Ian Collins <ian-news@hotmail.com> - 2013-06-23 00:52 +1200
  Re: compressable data Mok-Kong Shen <mok-kong.shen@t-online.de> - 2013-06-22 15:06 +0200
  Re: compressable data Tim Rentsch <txr@alumni.caltech.edu> - 2013-07-07 06:44 -0700
    Re: compressable data malcolm.mclean5@btinternet.com - 2013-07-09 10:42 -0700
      Re: compressable data "osmium" <r124c4u102@comcast.net> - 2013-07-09 13:33 -0500
        Re: compressable data malcolm.mclean5@btinternet.com - 2013-07-13 08:01 -0700
          Re: compressable data "osmium" <r124c4u102@comcast.net> - 2013-07-13 10:58 -0500
      Re: compressable data Tim Rentsch <txr@alumni.caltech.edu> - 2013-08-02 17:30 -0700

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