Invert an Array

invert_array.rb

def invert original
  result = Marshal.load Marshal.dump(original)

  original.each_with_index do |row, r_index|
    row.each_with_index do |column, c_index|
      result[c_index][r_index] = column
    end
  end

  result
end

array = [[1,2],[3,4]]
invert array