zipメソッド

　とりあえずメモだけ。配列を2次元化できる？
　統計とかとるときに使えるかな？

[1] pry(main)> a=[1,2,3]
=> [1, 2, 3]
[2] pry(main)> b=[3,4,5]
=> [3, 4, 5]
[3] pry(main)> c=[5,6,7]
=> [5, 6, 7]
[4] pry(main)> a.zip(b)
=> [[1, 3], [2, 4], [3, 5]]
[5] pry(main)> a.zip(b.zip(c))
=> [[1, [3, 5]], [2, [4, 6]], [3, [5, 7]]]
[6] pry(main)> a.zip(b.zip, c.zip)
=> [[1, [3], [5]], [2, [4], [6]], [3, [5], [7]]]
[7] pry(main)> a.zip(b.zip, c.zip).flatten
=> [1, 3, 5, 2, 4, 6, 3, 5, 7]
[8] pry(main)> a.zip(b.zip, c.zip)
=> [[1, [3], [5]], [2, [4], [6]], [3, [5], [7]]]
[9] pry(main)> a.zip(b.zip.flatten, c.zip)
=> [[1, 3, [5]], [2, 4, [6]], [3, 5, [7]]]
[10] pry(main)> a.zip(b.zip.flatten, c.zip.flatten)
=> [[1, 3, 5], [2, 4, 6], [3, 5, 7]]
[11] pry(main)> d=a.zip(b.zip.flatten, c.zip.flatten)
=> [[1, 3, 5], [2, 4, 6], [3, 5, 7]]
[12] pry(main)> d[1]
=> [2, 4, 6]
[13] pry(main)> d[1][1]
=> 4
[14] pry(main)> d[0][0]
=> 1
[15] pry(main)> d[0][2]
=> 5
[16] pry(main)> d[0][1]
=> 3