1.1.3 • Published 9 years ago
binary-shannon-entropy v1.1.3
binary-shannon-entropy
Calculate the shannon entropy of a buffer.
Example
var calc = require('binary-shannon-entropy');
calc(Buffer('aaaaa')); // => 0
calc(Buffer('fffff')); // => 0
calc(Buffer('aafaa')); // => 0.7219280948873623
calc(Buffer('abcdef')); // => 2.584962500721156
Installation
$ npm install binary-shannon-entropy
API
calc(buf, start)
Return a number between 0
and 8
, giving the Shannon entropy to the base of 2.
Optionally limit the area in the buffer to inspect by start
and end
.
Algorithm
H = -Sum(P_i * log2(P_i))
License
MIT