title: mnist-score for GANs on mnist data-set returns a logits tensor of [batch, 10]
body: <p>I use <a href="https://github.com/tensorflow/models/blob/master/research/gan/mnist/util.py" rel="nofollow noreferrer">this code</a> to calculate mnist-score (inception score).
  the function <code>mnist_score</code> returns the score as a tensor. how can i convert it to float?</p>
  
  <pre><code>def mnist_score(images, graph_def_filename=None, input_tensor=INPUT_TENSOR,
                  output_tensor=OUTPUT_TENSOR, num_batches=1):
    """Get MNIST logits of a fully-trained classifier.
    Args:
      images: A minibatch tensor of MNIST digits. Shape must be
        [batch, 28, 28, 1].
      graph_def_filename: Location of a frozen GraphDef binary file on disk. If
        `None`, uses a default graph.
      input_tensor: GraphDef's input tensor name.
      output_tensor: GraphDef's output tensor name.
      num_batches: Number of batches to split `generated_images` in to in order to
        efficiently run them through Inception.
    Returns:
      A logits tensor of [batch, 10].
    """
    images.shape.assert_is_compatible_with([None, 28, 28, 1])
  
    graph_def = _graph_def_from_par_or_disk(graph_def_filename)
    mnist_classifier_fn = lambda x: tfgan.eval.run_image_classifier(  # pylint: disable=g-long-lambda
        x, graph_def, input_tensor, output_tensor)
  
    score = tfgan.eval.classifier_score(
        images, mnist_classifier_fn, num_batches)
    score.shape.assert_is_compatible_with([])
  
    return score
  </code></pre>