東大2年の簡単なパーセプトロンの課題

perceptron_report.rb

#! /usr/bin/env ruby
require "matrix"

# training data
v1 = [Vector[1, 3, 0], 1]
v2 = [Vector[1, 4, 3], 1]
v3 = [Vector[1, 6, 4], 1]
v4 = [Vector[1, 1, 2], 2]
v5 = [Vector[1, 3, 5], 2]
v6 = [Vector[1, 4, 6], 2]
all_data = [v1, v2, v3, v4, v5, v6]

# -> vector, bool
def learn(weights, data)
  w1    = weights[0]
  w2    = weights[1]
  v     = data[0]
  label = data[1]

  outputs = [v.dot(w1), v.dot(w2)]
  success = !outputs[0].eql?(outputs[1]) && outputs.find_index(outputs.max).eql?(label - 1)

  return [weights, true] if success

  if (label == 1)
    new_weights = [weights[0] + v, weights[1] - v]
  elsif (label == 2)
    new_weights = [weights[0] - v, weights[1] + v]
  else
    raise "wrong label"
  end

  return [new_weights, false]
end

# Let's learn!
epoch = 0
weights_trained = [Vector[1, 0, 0], Vector[1, 0, 0]]

loop do
  never_failed = true

  all_data.each do |data|
    weights_trained, success = learn(weights_trained, data)
    never_failed = false if !success
  end

  epoch += 1
  break if never_failed
end

puts "epoch: #{epoch}"
puts weights_trained

上のコードで重みが出力されるので、そこから決定境界を求めればいい
問題は以下