[Haskell-cafe] Toy compression algorithms [was: A very edgy language]

Andrew Coppin andrewcoppin at btinternet.com
Wed Jul 11 15:06:33 EDT 2007


Bulat Ziganshin wrote:
> Hello ajb,
>
> Wednesday, July 11, 2007, 7:55:22 AM, you wrote:
>   
>> Not really.  LZW is basically PPM with a static (and flat!) frequency
>> prediction model.  The contexts are build in a very similar way.
>>     
>
> what you mean by "flat" and "static" applied to PPM? static PPM models
> exist - they carry probabilities as separate table very like static
> Huffman encoding. is "flat" the same as order-0?
>   

I think he meant "flat" as in "pr(z) = 0 | 1"...

As for "static", I'm not so sure that's actually correct.



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