Re: diehard and ent results quesion

From: Tom St Denis (tomstdenis@iahu.ca)
Date: 02/19/03 

From: "Tom St Denis" <tomstdenis@iahu.ca>
Date: Wed, 19 Feb 2003 07:15:19 -0500

"Cyber Vagrant" <cybervagrant@yahoo.com> wrote in message
news:9f8a576b.0302181946.4b07941d@posting.google.com...
> I use Ent to test a varity combination generators I've been working on
> lately. Entropy is synonomous with randomness, more is better.

Not quite. Entropy is the measure of uncertainty. That is how many bits
does it require in a decision graph to distinguish this message from all
other messages. E.g. if you had only "yes" or "no" then only one bit would
be required.

The actual amount of "entropy" per message is not a fixed number. Say you
compress a text with deflate you might hit 3bpb which would indicate each
char has 3 bits of entropy. However, that same message through
BWT+RLE+MTF+Huffman [aka BZIP2] may hit 1.5bpb.

Tom

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