title: What means T.alloc
body: <p>I'm learning keras and I'm using a code about music generation to learn. I have checked the code and I have showed this, I think this is theano:</p>
  
  <pre><code>start_note_values = T.alloc(np.array(0, dtype=np.int8), 5 * 128, 1, 2)
  </code></pre>
  
  <p>The function is:</p>
  
  <pre><code>def y_labels(y): 
      start_note_values = T.alloc(np.array(0, dtype=np.int8), BATCH_SIZE * NUM_TIMESTEPS, 1, OUTPUT_LAYER)
      correct_choices = y[:, :, :-1, :].reshape((BATCH_SIZE * NUM_TIMESTEPS, NUM_NOTES - 1, OUTPUT_LAYER))        
      features = T.concatenate([start_note_values, correct_choices], axis=1)
      return features.reshape((BATCH_SIZE, NUM_TIMESTEPS, NUM_NOTES, OUTPUT_LAYER)).transpose((0, 2, 1, 3)).reshape((BATCH_SIZE * NUM_NOTES, NUM_TIMESTEPS, OUTPUT_LAYER))
  
  get_labels_shape = lambda shape: [BATCH_SIZE * NUM_NOTES, NUM_TIMESTEPS, OUTPUT_LAYER]
  
  previous_notes = Sequential([
      Lambda(y_labels, output_shape=get_labels_shape, batch_input_shape=(BATCH_SIZE, NUM_TIMESTEPS, NUM_NOTES, OUTPUT_LAYER), name='y_labels')
  ])
  </code></pre>
  
  <p>I don't understand what it means, can someone explain me? The input has this format:</p>
  
  <pre><code>X = (440, 128, 300) 
  </code></pre>
  
  <p>There is a way to right this in keras?
  Thank you guys!</p>