Given a 2D array of m x n dimension, how can I loop through them in anti-clockwise fashion?

For example:

matrix = [  [   1,    2,   3,    4  ],  [   5,    6,   7,    8  ],  [   9,   10,  11,   12  ],  [  13,   14,  15,   16  ]]1st loop: 1, 5, 9, 13, 14, 15, 16, 12, 8, 4, 3, 22nd loop: 6, 10, 11, 7, 6

I really don't mind if the implementation is given in ruby or js

My current solution is like this:

  (1..rotate).each do    bottom_left_corner = i    top_right_corner   = j    start_nth_layer = 1; end_nth_layer = matrix.length - 2    matrix.reverse_each do      matrix[bottom_left_corner].unshift(matrix[bottom_left_corner - 1].shift) if bottom_left_corner > 0      matrix[top_right_corner] << matrix[top_right_corner + 1].pop if top_right_corner < matrix.length - 1      bottom_left_corner -= 1; top_right_corner += 1    end    nth_layer(matrix, start_nth_layer, end_nth_layer)  end

Update

The output doesn't format doesn't matter, as long as it outputs the correct order.

Purpose of the problem

The purpose of this problem is traverse these arrays anti-clockwise, layer by layer, until no more layers. For each traversal, we shift the values in anti-clockwise. For example:

 Iteration 1:        Iteration 2:       Iteration 3: ==============      =============      ============== 1    2   3   4      2   3   4   8      3   4   8  12 5    6   7   8      1   7  11  12      2  11  10  16 9   10  11  12  =>  5   6  10  16  =>  1   7   6  15 13  14  15  16      9  13  14  15      5   9  13  14