C4.5

Note: This is a fork of learningjs.

C4.5 decision tree generation algorithm in JavaScript.

Install

npm install c4.5

Usage

data.csv

id,attr1,attr2,attr3,class
1,A,70,True,CLASS1
2,A,90,True,CLASS2
3,A,85,False,CLASS2
4,A,95,False,CLASS2
5,A,70,False,CLASS1
6,B,90,True,CLASS1
7,B,78,False,CLASS1
8,B,65,True,CLASS1
9,B,75,False,CLASS1
10,C,80,True,CLASS2
11,C,70,True,CLASS2
12,C,80,False,CLASS1
13,C,80,False,CLASS1
14,C,96,False,CLASS1

var fs = require('fs');
var csv = require('csv');
var C45 = require('c4.5');

fs.readFile('data.csv', function(err, data) {
  if (err) {
    console.error(err);
    return false;
  }

  csv.parse(data, function(err, data) {
    if (err) {
      console.error(err);
      return false;
    }

    var headers = data[0];
    var features = headers.slice(1,-1); // ["attr1", "attr2", "attr3"]
    var featureTypes = ['category','number','category'];
    var trainingData = data.slice(1).map(function(d) {
      return d.slice(1);
    });
    var target = headers[headers.length-1]; // "class"
    var c45 = C45();

    c45.train({
        data: trainingData,
        target: target,
        features: features,
        featureTypes: featureTypes
    }, function(error, model) {
      if (error) {
        console.error(error);
        return false;
      }

      var testData = [
        ['B',71,'False'],
        ['C',70,'True'],
      ];

      console.log(model.classify(testData[0]) === 'CLASS1'); // true
      console.log(model.classify(testData[1]) === 'CLASS2'); // true
    });
  });
});

Saving

var c45 = C45();
c45.train({...})
fs.writeFileSync('state.json', c45.toJSON())

Restoring

var c45 = C45();
var state = require('state.json')
c45.restore(state)
var model = c45.getModel()
console.log(model.classify(testData[0])) // 'CLASS1'

Test

npm test

License

MIT