Shannon Entropy calculation to measure the information gain of an array of objects.
[Shannon entropy](http://en.wikipedia.org/wiki/Entropy_(information_theory) calculation to measure the information gain of an array of objects (i.e. average unpredictability in a random variable) in bits.
The algorithm is based on the equation
$ npm install shannon-entropy
var entropy = require('shannon-entropy');
entropy.calculateEntropy(items, columns, function(entropy) {
console.log(entropy);
});
items
is an array of objects on which the entropy algorithm is performed. The columns
array includes all the keys of the object the entropy should be calculated of. The callback returns an object containing each key defined in the columns
array and the value of the calculated entropy in bits.
var entropy = require('shannon-entropy');
var items = [
{
name: "Alex",
email: "[email protected]",
year: 1980
},
{
name: "Peter",
email: "[email protected]",
year: 1990
}, {
name: "Bob",
email: "[email protected]",
year: 2000
}
];
var columns = ["name", "email", "year"];
entropy.calculateEntropy(items, columns, function(entropy) {
console.log(entropy);
});
The entropy of each property in bits.
{
name: 4.754887502163468,
email: 2.7548875021634687,
year: 0
}
$ npm test
{ name: 4.754887502163468, email: 2.7548875021634687, year: 0 }
All tests OK
Feel free to get in touch.
Copyright (C) 2013 Alexander Schuch
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