Hands-On Reinforcement Learning with Python

Policy gradient

The policy gradient is one of the amazing algorithms in reinforcement learning (RL) where we directly optimize the policy parameterized by some parameter . So far, we have used the Q function for finding the optimal policy. Now we will see how to find the optimal policy without the Q function. First, let's define the policy function as , that is, the probability of taking an action a given the state s. We parameterize the policy via a parameter as , which allows us to determine the best action in a state.

The policy gradient ...