I have already trained a NN with training data set $[X,Y]$. Lets consider this model is called $M$. Now, I have a new data set $[X_{new}, Y_{new}]$. I would like to Update my model $M$ with data set $[X_{new}, Y_{new}]$ without retraining it from scratch.
My question is: is it possible to update the model this way or I must retrain this? If it is possible to update, how?