マルコフ連鎖による文章生成

markov3.rb

# coding: utf-8
require 'natto'
require 'csv'

# 分かち書きで出力
$nm = Natto::MeCab.new(dicdir: "/usr/lib/mecab/dic/mecab-ipadic-neologd", output_format_type: :wakati)
def mecab(txt)
  parse = $nm.parse(txt)
  parse = "BOS " + parse + "EOS"
  return parse
end

data = []
start = []
file = File.foreach("text.txt") do |line|
  res = mecab(line)
  res.split(" ").each_cons(3) do |a| # 配列を前から3語ずつ1ずらしで保存する
    h = {'head' => a[0], 'middle' => a[1], 'end' => a[2]}
	data << h
  end
end

CSV.open("data.csv", "wb") do |csv|
  csv << ['head', 'middle', 'end']
  data.each do |h|
	csv << h.values
  end
end

x = data.size
while true
  exit = gets.chomp
  break if exit == "exit"
  while true
    n = rand(x) # ランダムで最初の2語を決定
	start = data[n]['head']
	if start == "BOS"
	  t1 = data[n]['middle']
	  t2 = data[n]['end']
	  new_text = t1 + t2
	  break
	end
  end
  #前2語が同じもの(3語目の候補)リストを作成
  while true
    next_word = []
  	data.each do |hash|
	  if hash['head'] == t1 && hash['middle'] == t2
  	  	next_word << hash 
	  end
  	end
  	break if next_word.size == 0
  	num = rand(next_word.size) # 乱数で次の語を決定する
  	new_text = new_text + next_word[num]['end']
  	break if next_word[num]['end'] == "EOS"
    # 二語の更新
  	t1 = next_word[num]['middle']
  	t2 = next_word[num]['end']
  end
  # EOSを削除して、結果出力
  tweet = new_text.gsub!(/EOS$/,'')
  puts tweet
end