Class: Treat::Workers::Learners::Classifiers::ID3

Inherits:
Object
  • Object
show all
Defined in:
lib/treat/workers/learners/classifiers/id3.rb

Overview

Classification based on Ross Quinlan’s ID3 (Iterative Dichotomiser 3) decision tree algorithm.

Original paper: Quinlan, J. R. 1986. Induction of Decision Trees. Mach. Learn. 1, 1 (Mar. 1986), 81-106.

Constant Summary collapse

@@classifiers = 
{}

Class Method Summary collapse

Class Method Details

.classify(entity, options = {}) ⇒ Object 



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# File 'lib/treat/workers/learners/classifiers/id3.rb', line 14

def self.classify(entity, options = {})
  dset = options[:training]
  prob = dset.problem
  if !@@classifiers[prob]
    dec_tree = DecisionTree::ID3Tree.new(
    prob.feature_labels.map { |l| l.to_s }, 
    dset.items.map { |i| i[:features] }, 
    prob.question.default, prob.question.type)
    dec_tree.train
    @@classifiers[prob] = dec_tree
  else
    dec_tree = @@classifiers[prob]
  end
  vect = prob.export_features(entity, false)
  dec_tree.predict(vect)
end