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Re: how to combine the probability of disjoint symbol models?

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On Friday, March 23, 2012 1:06:40 AM UTC+10:30, biject wrote:
> On Mar 22, 6:35 am, moogie <budgetan...@mystarship.com> wrote:
> 
>  The fact is you don't get something from nothing.  And Yes many of
> the files
> will compress smaller. However in general the length of the second
> compressed
> file will be longer. Here are the problems. You have to have data in
> the output
> file that tells what the length of Smin is.  Then you have to have
> information
> on decompression to tell where you switched from your full arithmetic
> to the
> adding of the trailing of the extra bits.
>  Actually with care you can do all the above bijectively but in the
> end for
> general files you gain nothing.  But if the first compression weak for
> the
> limited subset of files your using you might gain something for the
> limited
> subset.

Yes i agree, it is necessary to record the number of bits for the size of a Symbol. And I also agree that either a symbol is necessary to inform the decompressor to switch to the extra bits ( or record the file length)

I also agree that there is a limited subset of all posible files where the scheme will work: the set of files where the minimum number of bits necessary to create an alphabet of symbols (in which sequential "reading" of symbols from the file is such that no symbol is repeated) and that minimum number is less than half the file size bits (to allow at least two symbols to be written)

The set of Compressed Files of a given size should be highly represented within this limited set as the symbol size will should be  lower than uncompressed files that contain repeating patterns and thus need more bits in the symbol size.

I guess it depends on the source (i.e. the compressed file) whether the gains will out weigh this extra information necessary.

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how to combine the probability of disjoint symbol models? moogie <budgetanime@mystarship.com> - 2012-03-22 05:35 -0700
  Re: how to combine the probability of disjoint symbol models? moogie <budgetanime@mystarship.com> - 2012-03-22 05:36 -0700
  Re: how to combine the probability of disjoint symbol models? biject <biject.bwts@gmail.com> - 2012-03-22 07:36 -0700
    Re: how to combine the probability of disjoint symbol models? moogie <budgetanime@mystarship.com> - 2012-03-22 17:48 -0700
  Re: how to combine the probability of disjoint symbol models? Thomas Richter <thor@math.tu-berlin.de> - 2012-03-22 17:04 +0100
    Re: how to combine the probability of disjoint symbol models? moogie <budgetanime@mystarship.com> - 2012-03-22 20:02 -0700
      Re: how to combine the probability of disjoint symbol models? moogie <budgetanime@mystarship.com> - 2012-03-22 21:02 -0700
        Re: how to combine the probability of disjoint symbol models? biject <biject.bwts@gmail.com> - 2012-03-22 21:29 -0700
          Re: how to combine the probability of disjoint symbol models? moogie <budgetanime@mystarship.com> - 2012-03-22 22:38 -0700
  Re: how to combine the probability of disjoint symbol models? moogie <budgetanime@mystarship.com> - 2012-03-23 05:42 -0700

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