title: plotting training data in keras outputs empty graph
body: <p>I am trying to plot the training data. I am using</p>
  
  <pre><code>for i in range(epoch_size):
      history = model.fit(trainingX[:10], trainingY[:10], epochs=1, batch_size=batch_size,callbacks = [early_stop], verbose=2)
  </code></pre>
  
  <p>in loop of 50</p>
  
  <p>and then</p>
  
  <pre><code>plt.plot(history.history['acc'])
  plt.title('model accuracy')
  plt.ylabel('acc')
  plt.xlabel('epoch')
  plt.legend(['train', 'test'], loc='upper left')
  plt.show()
  </code></pre>
  
  <p>yet the plot is always empty, why is that?
  <a href="https://i.stack.imgur.com/sJrf1.png" rel="nofollow noreferrer">img</a></p>