title: Creating log directory in tensorboard
body: <p>I am trying to learn how to use tensorboard and I would like to have it run in my program. I do not understand how to create a log directory. These are the lines I have for running tensorboard.</p>
  
  <pre><code>   summary_writer = tf.train.SummaryWriter('/tensorflow/logdir', sess.graph_def)
     tensorboard --logdir=tensorflow/logdir
  </code></pre>
  
  <p>The error message that I got was </p>
  
  <pre><code>Cannot assign to operator
  </code></pre>