Study Reinforcement Learning

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track one of eight

Foundations

About 27 hours, 24% of the whole. 6 lectures, 5 with an exercise.

policy πenvironmentactionstate, reward
Figure.The loop itself: an MDP.

MDPs, value functions, policy gradients, actor-critic, trust regions, PPO. Every other track builds on these.

Start with lecture 01. Each lecture lists what to read first, and ends with a checkpoint: something to do with the page closed.

  1. 01MDPs and Bellman Equations2–3 h

    checkpointWrite down both Bellman equations and explain what value iteration does, without notes.

    exercisevideo← start here

  2. 02Policy Gradients from Scratch3–4 h + exercise

    checkpointDerive ∇J = E[∇ log π · R] and say why the environment dynamics drop out. Then do the exercise: exercises/02-policy-gradients/ (implement REINFORCE, get CartPole solved, tests green).

    exercisevideo

  3. 03Value Functions & Q-Learning2–3 h

    checkpointExplain when you'd reach for a value-based method instead of a policy-gradient one.

    exercisevideo

  4. 04Actor-Critic Methods2–3 h

    checkpointExplain why subtracting a learned baseline reduces variance without biasing the gradient.

    exercisevideo

  5. 05Trust Region Policy Optimization (TRPO)2–4 h

    checkpointExplain what "trust region" means here and what problem it's solving.

  6. 06PPO - Proximal Policy Optimization2–3 h

    checkpointWrite the clipped surrogate objective and explain what the clip does and why.

    exercise

Exercises in this track

  • 01-mdps: value iteration on a gridworld (with lecture 01)
  • 02-policy-gradients: REINFORCE, solve CartPole (with lecture 02)
  • 03-q-learning: tabular Q-learning on FrozenLake (with lecture 03)
  • 04-actor-critic: actor-critic with a learned baseline, on CartPole (with lecture 04)
  • 05-ppo: PPO with GAE, solve CartPole (with lecture 06)

On video