Policy objective functions

Let's discuss now how to optimize a policy. In policy methods, our main objective is that a given policy  with parameter vector  finds the best values of the parameter vector. In order to measure which is the best, we measure  the quality of the policy  for different values of the parameter vector .

Before discussing the optimization methods, let's first figure out the different ways to measure the quality of a policy :

• If it's an episodic environment,  can be the value function of the start state  that is if it starts from any state , then the value function of it would be the expected sum of reward from that state onwards. Therefore,

• If it's a continuing environment,  can be the average value function of the states. So, if the environment goes on and...