title: How can I average an array of arrays in python?
body: <p>I have a simulation that runs over many times. Each time an array is produced and I insert it into a larger array keeping track of all the data. for example </p>
  
  <pre><code>record = []
  for i in range(2):
       r = random.random()
       array = numpy.arange(20)*r
       array.shape = (10,2)
       record.append(array)
  record = numpy.array(record)
  </code></pre>
  
  <p>which produces:</p>
  
  <pre><code>[[[  0.           0.88765927]
    [  1.77531855   2.66297782]
    [  3.55063709   4.43829637]
    [  5.32595564   6.21361492]
    [  7.10127419   7.98893346]
    [  8.87659274   9.76425201]
    [ 10.65191128  11.53957056]
    [ 12.42722983  13.3148891 ]
    [ 14.20254838  15.09020765]
    [ 15.97786693  16.8655262 ]]
  
   [[  0.           0.31394919]
    [  0.62789839   0.94184758]
    [  1.25579677   1.56974596]
    [  1.88369516   2.19764435]
    [  2.51159354   2.82554274]
    [  3.13949193   3.45344112]
    [  3.76739031   4.08133951]
    [  4.3952887    4.70923789]
    [  5.02318709   5.33713628]
    [  5.65108547   5.96503466]]]
  </code></pre>
  
  <p>Since each <code>array</code> represents a simulation in my program. I would like to average the 2 different arrays contained within <code>record</code>. </p>
  
  <p>basically I would like an array with the same dimensions as <code>array</code> but it would be an average of all the individual runs. </p>
  
  <p>I could obviously just loop over the arrays but there is a lot of data in my actual simulations so I think it would be very costly on time </p>
  
  <p>example out put (obviously it wouldn't be zero):</p>
  
  <pre><code>average = [[0.0, 0.0]
             [0.0, 0.0]
             [0.0, 0.0]
             [0.0, 0.0]
             [0.0, 0.0]
             [0.0, 0.0]
             [0.0, 0.0]
             [0.0, 0.0]
             [0.0, 0.0]
             [0.0, 0.0]]
  </code></pre>