input: Write a function to calculate the average of the elements in a 2-dimensional array. The function should return the average as a floating-point number. If the input array is empty, the function should return 0.
  
  def averageMatrix(matrix):
      if not matrix:
          return 0
      total_sum = 0
      count = 0
      for row in matrix:
          for element in row:
              total_sum += element
              count += 1
      return total_sum / count if count != 0 else 0
  
  a = [[3,2,6],
       [8,5,9],
       [4,7,1]]
  
  assert averageMatrix(a) == 5.0
  assert averageMatrix([[1, 2, 3], [4, 5, 6]]) == 3.5
  assert averageMatrix([[1, 1], [1, 1]]) == 1.0
  assert averageMatrix([]) == 0
  assert averageMatrix([[10]]) == 10.0
output: def averageMatrix(matrix):
      if not matrix:
          return 0
      total_sum = 0
      count = 0
      for row in matrix:
          for element in row:
              total_sum += element
              count += 1
      return total_sum / count if count != 0 else 0