title: How to use tf.metrics.accuracy?
body: <p>I want to use <a href="https://www.tensorflow.org/api_docs/python/tf/metrics/accuracy" rel="nofollow noreferrer"><code>tf.metrics.accuracy</code></a> to track the accuracy of my predictions, but I am unsure of how to use the update_op (<code>acc_update_op</code> below) that the function returns:</p>
  
  <pre><code>accuracy, acc_update_op = tf.metrics.accuracy(labels, predictions)
  </code></pre>
  
  <p>I was thinking that adding it to <code>tf.GraphKeys.UPDATE_OPS</code> would make sense, but I am not sure how to do this.</p>