title: How can I combine two RNN models
body: <p>I have a question with tensorflow, now I'm using tensorflow built two RNN models. </p>
  
  <ul>
  <li><p>RNN1(encoder) is 3 layers LSTM units with cell size 256</p></li>
  <li><p>RNN2(decoder) is 3 layers LSTM units with cell size 512. </p></li>
  </ul>
  
  <p>Now I want combine two RNNs by the state, which means the last state
     of RNN1 is the first state of RNN2. I want to ask how to implement
     that?</p>
  
  <p>I have tried set RNN1 and RNN2 with the same cell size(512) and use this code:</p>
  
  <pre><code>decoder_initial_state = cell.zero_state(batch_size, tf.float32).clone(cell_state=encoder_state)`    #this code is from Internet.
  </code></pre>
  
  <p>but I think it is not right.</p>
  
  <p>Any help is appreciated
  Thank you </p>