title: Keras: use Tensorboard with train_on_batch()
body: <p>For the keras functions <code>fit()</code> and <code>fit_generator()</code> there is the possibility of tensorboard visualization by passing a <code>keras.callbacks.TensorBoard</code> object to the functions. For the <code>train_on_batch()</code> function there obviously are no callback available. Are there other options in keras to create a Tensorboard in this case?</p>