art.rb

art.rb

class Art
  L = 2
  MAX_EPOCH = 20

  def initialize(n, m, p = 0.45)
    @n = n
    @m = m
    @p = p
    @w1 = Array.new(n) { Array.new(m) { 1.0 / (1+n) } }
    @w2 = Array.new(m) { Array.new(n) { 1.0 } }
  end

  def teach(vecs)
    print_epoch(0)

    MAX_EPOCH.times do |i|
      w1_old = @w1.dup
      w2_old = @w2.dup

      process_epoch(vecs)
      print_epoch(i+1)

      break if w1_old == @w1 && w2_old == @w2
    end
  end

  def process_epoch(vecs)
    vecs.each do |vec|
      process_vector(vec)
    end
  end

  def process_vector(vec)
    # step 4
    s_out = vec

    # step 5
    s_out_norm = sum(s_out)

    # step 6
    z_in = s_out.dup
    z_out = z_in.dup

    # step 7
    y_in = calc_y_in(z_out)

    # step 8
    while true  # !!!DANGEROUS!!!
      #step 9
      jj = y_in.index(y_in.sort.last)

      #step 10
      z_out = []
      @n.times do |i|
        z_out[i] = s_out[i] * @w2[jj][i]
      end

      # step 11
      z_out_norm = sum(z_out)

      # step 12
      if (z_out_norm.to_f / s_out_norm) > @p
        break
      else
        y_in[jj] = -1
      end
    end

    # step 13
    @n.times do |i|
      @w1[i][jj] = (L * z_out[i]).to_f / (L-1+z_out_norm)
    end
    @w2[jj] = z_out.dup
  end

  def to_s
    out = "w1:\n"
    out << w_to_s(@w1)
    out << "w2:\n"
    out << w_to_s(@w2, "%-3d")
    out << "\n\n"
    out
  end

  private

  def sum(vec)
    vec.inject(&:+)
  end

  def calc_y_in(vec)
    y_in = Array.new(@m) { 0 }
    @m.times do |j|
      @n.times do |i|
        y_in[j] += @w1[i][j] * vec[i]
      end
    end
    y_in
  end

  def w_to_s(w, format = "%-7.3f")
    out = ""
    w.each do |raw|
      raw.each do |el|
        out << format % [el]
      end
      out << "\n"
    end
    out
  end

  def print_epoch(num)
    puts "=== Epoch #{num} ==="
    puts self
  end
end







vectors = [
  [1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0],
  [1, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0],
  [1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0],

  [1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0],
  [1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0],
  [1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0],

  [0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1],
  [0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1],
  [0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1]
]

ps = 0.4, 0.7, 0.9
ps.each do |p|
  puts "===== P = #{p} ====="
  net = Art.new(13, 9, p)
  net.teach(vectors)
end