title: Keras callbacks in custom epoch loop
body: <p>I use keras to train an LSTM. The input sequences are of different length. Lets say the sequences have lengths between 1 and <code>num_seq</code>. Therefore, I group the sequences by length in each epoch in order to use a batch size > 1:</p>
  
  <pre><code>for epoch in xrange(nb_epochs):
   for i in range(1,num_seq):
    X,y = get_sequences(length=i)
    model.fit(X,y,batch_size=100,epochs=1, validation_split=0.1, callbacks=None)
  </code></pre>
  
  <p>Because I use a custom loop over the epochs, callbacks which use the epoch information do not work properly (e.g. the tensorboard, history, etc). What would be a way around this problem? Is there a way to tell the fit function, which epoch it currently does?</p>