title: How to update trained Naive Bayes model saved with joblib
body: <p>I am trying to update my already trained model so that it can correct the errors it is making. For that, I am partially fitting the new data for which it was giving incorrect labels with the new correct labels</p>
  
  <p>I have saved my Bayesian model in a file like this:</p>
  
  <pre><code>model1 = MultinomialNB()                    #NaiveBayes model
  model1.partial_fit(features_matrix, label_matrix, [0,1,2])
  filename = 'trained_NBmodel.pkl'              #saving the trained model
  joblib.dump(model1, filename)
  </code></pre>
  
  <p>and then loading it another file like this:</p>
  
  <pre><code>loaded_model = joblib.load('trained_NBmodel.pkl')
  loaded_model.partial_fit(new_features_matrix, new_label_matrix)
  filename = 'trained_NBmodel.pkl'              #saving the trained model
  joblib.dump(loaded_model, filename)
  </code></pre>
  
  <p>now it should use the updated model and if new_features_matrix is given to predict, it should predict new_label_matrix with high accuracy but the model is not. It gives the same label matrix as it was giving before refitting. Could it be that I have trained my initial model with similar data many times with different labels that it is not able to learn from fewer data? </p>