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

[Bulat Ziganshin]

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?

>> the devil in details. just imagine size of huffman table with 64k
>> entries :)

> If you're allowed to pick your code values, you can do this extremely
> compactly.  Some compression schemes optimised for English separates
> words from the intermediate space and assigns a Huffman code to each
> word.  The tables aren't that big (though the space to hold the words
> might be).

can you give a link? i never heard about such algorithm


-- 
Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com