Implements deterministic greedy action selection for Q-learners [A, ACTION] = GREEDYACT(A, STATE, ACTIONS, REWARDS, PARAMS) Implements greedy deterministic action selection, using a Q-table indexed by the agent's state and action. The action with the highest Q-value is chosen (breaking ties randomly). Supports discrete states and actions, with 1 action variable only. Requires the size of the Q-table to be cached under a field named 'qsize'. See also act