MaxHistoryTrackerFeaturizer featurizer creates a feature vector
(num_unique_turns, max_history, num_input_features).
Now I understand where the max_history parameter and the num_input_features come from.
However, it is still a mystery for num_input_features.
I assume in the question, you meant what is
num_unique_turns. It is a number of training examples, or in the context of
rasa_core it is a number of actions to be predicted (we consider an action predicted by
rasa_core as a
turn of the dialogue). We call it
unique because by default the featurizer performs deduplication based on the corresponding feature vectors