decisiontree/examples/continuous-id3.rb

require "rubygems"
require "decisiontree"
include DecisionTree

# ---Continuous---

# Read in the training data
training = []
attributes = nil

File.open("data/continuous-training.txt", "r").each_line do |line|
  data = line.strip.chomp(".").split(",")
  attributes ||= data
  training_data = data.collect do |v|
    case v
    when "healthy"
      1
    when "colic"
      0
    else
      v.to_f
    end
  end
  training.push(training_data)
end

# Remove the attribute row from the training data
training.shift

# Instantiate the tree, and train it based on the data (set default to '1')
dec_tree = ID3Tree.new(attributes, training, 1, :continuous)
dec_tree.train

# ---Test the tree---

# Read in the test cases
# Note: omit the attribute line (first line), we know the labels from the training data
test = []
File.open("data/continuous-test.txt", "r").each_line do |line|
  data = line.strip.chomp(".").split(",")
  test_data = data.collect do |v|
    if v == "healthy" || v == "colic"
      v == "healthy" ? 1 : 0
    else
      v.to_f
    end
  end
  test.push(test_data)
end

# Let the tree predict the output and compare it to the true specified value
test.each do |t|
  predict = dec_tree.predict(t)
  puts "Predict: #{predict} ... True: #{t.last}"
end