title: efficient array concatenation
body: <p>Im trying to concatenate several hundred arrays size totaling almost 25GB of data. I am testing on 56 GB machine, but i receive memory error. I reckon the way I do my precess is ineffecient and is sucking lots of memory. This is my code:</p>
  
  <pre><code>    for dirname, dirnames, filenames in os.walk('/home/extra/AllData'): 
          filenames.sort()
      BigArray=numpy.zeros((1,200))
      for file in filenames:
          newArray[load(filenames[filea])
          BigArray=numpy.concatenate((BigArrat,newArray))
  </code></pre>
  
  <p>any idea, thoughts or solutions?</p>
  
  <p>Thanks</p>