title: Counterpart of hstack and vstack in Tensorflow
body: <p>What would be the correct counterpart of the <code>numpy</code> functions <code>hstack</code> and <code>vstack</code> in <strong>Tensorflow</strong>?</p>
  
  <p>There is <code>tf.stack</code> and <code>tf.concat</code> in <code>Tensorflow</code>, but i don't know how to use them or use the correct <code>axis</code> value, to achieve the same behaviour in Tensorflow.</p>