Value Iteration implementieren

Value Iteration ist eine zentrale Methode im RL, um die optimale Policy zu finden. Dabei wird die Wertfunktion für jeden Zustand iterativ verbessert, bis sie konvergiert – so wird die optimale Policy ermittelt. Du startest mit einer initialisierten Wertfunktion V und einer policy, beides ist für dich vorgeladen. Dann aktualisierst du sie in einer Schleife, bis die Wertfunktion konvergiert, und siehst die Policy in Aktion.

Die Funktion get_max_action_and_value(state, V) wurde bereits für dich geladen.

Diese Übung ist Teil des Kurses

Reinforcement Learning mit Gymnasium in Python

Anleitung zur Übung

Finde für jeden Zustand die Aktion mit dem maximalen Q-Wert (max_action) und den zugehörigen Wert (max_q_value).
Aktualisiere das Dictionary new_V und die policy basierend auf max_action und max_q_value.
Prüfe die Konvergenz, indem du kontrollierst, ob der Unterschied zwischen new_v und V für jeden Zustand kleiner als threshold ist.

Interaktive Übung

Vervollständige den Beispielcode, um diese Übung erfolgreich abzuschließen.

threshold = 0.001
while True:
  new_V = {}
  for state in range(num_states-1):
    # Get action with maximum Q-value and its value 
    max_action, max_q_value = ____
    # Update the value function and policy
    new_V[state] = ____
    policy[state] = ____
  # Test if change in state values is negligeable
  if all(abs(____ - ____) < ____ for state in ____):
    break
  V = new_V
render_policy(policy)

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Diese Übung ist Teil des Kurses

Reinforcement Learning mit Gymnasium in Python

Hohe SchwierigkeitSchwierigkeitsgrad

4.8+

Kurs kostenlos starten

Dive into the exciting world of Reinforcement Learning (RL) by exploring its foundational concepts, roles, and applications. Navigate through the RL framework, uncovering the agent-environment interaction. You'll also learn how to use the Gymnasium library to create environments, visualize states, and perform actions, thus gaining a practical foundation in RL concepts and applications.

Exercise 1: Fundamentals of reinforcement learning Exercise 2: What is Reinforcement Learning?Exercise 3: RL vs. other ML sub-domains Exercise 4: Scenarios for applying RL Exercise 5: Navigating the RL framework Exercise 6: RL interaction loop Exercise 7: Episodic and continuous RL tasks Exercise 8: Calculating discounted returns for agent strategies Exercise 9: Interacting with Gymnasium environments Exercise 10: Setting up a Mountain Car environment Exercise 11: Visualizing the Mountain Car Environment Exercise 12: Interacting with the Frozen Lake environment

Delve deeper into the world of RL focusing on model-based learning. Unravel the complexities of Markov Decision Processes (MDPs), understanding their essential components. Enhance your skill set by learning about policies and value functions. Gain expertise in policy optimization with policy iteration and value Iteration techniques.

Exercise 1: Markow-Entscheidungsprozesse Exercise 2: Eigene MDP-Komponenten für Frozen Lake Exercise 3: Zustands- und Aktionsräume erkunden Exercise 4: Übergangswahrscheinlichkeiten und Belohnungen Exercise 5: Policies und Zustandswertfunktionen Exercise 6: Eine deterministische Policy definieren Exercise 7: Zustandswerte für eine Policy berechnen Exercise 8: Policies vergleichen Exercise 9: Aktionswertfunktionen Exercise 10: Q-Werte berechnen Exercise 11: Eine Policy verbessern Exercise 12: Policy Iteration und Value Iteration Exercise 13: Policy Iteration für die optimale Policy anwenden Exercise 14: Value Iteration implementieren

Aktuelle Übung

Embark on a journey through the dynamic realm of Model-Free Learning in RL. Get introduced to to the foundational Monte Carlo methods, and apply first-visit and every-visit Monte Carlo prediction algorithms. Transition into the world of Temporal Difference Learning, exploring the SARSA algorithm. Finally, dive into the depths of Q-Learning, and analyze its convergence in challenging environments.

Exercise 1: Monte Carlo methods Exercise 2: Episode generation for Monte Carlo methods Exercise 3: Implementing first-visit Monte Carlo Exercise 4: Implementing every-visit Monte Carlo Exercise 5: Temporal difference learning Exercise 6: Implementing the SARSA update rule Exercise 7: Solving 8x8 Frozen Lake with SARSA Exercise 8: Q-learning Exercise 9: Implementing Q-learning update rule Exercise 10: Solving 8x8 Frozen Lake with Q-learning Exercise 11: Evaluating policy on a slippery Frozen Lake

Dive into advanced strategies in Model-Free RL, focusing on enhancing decision-making algorithms. Learn about Expected SARSA for more accurate policy updates and Double Q-learning to mitigate overestimation bias. Explore the Exploration-Exploitation Tradeoff, mastering epsilon-greedy and epsilon-decay strategies for optimal action selection. Tackle the Multi-Armed Bandit Problem, applying strategies to solve decision-making challenges under uncertainty.

Exercise 1: Expected SARSA Exercise 2: Expected SARSA update rule Exercise 3: Applying Expected SARSA Exercise 4: Double Q-learning Exercise 5: Implementing double Q-learning update rule Exercise 6: Applying double Q-learning Exercise 7: Balancing exploration and exploitation Exercise 8: Defining epsilon-greedy function Exercise 9: Solving CliffWalking with epsilon greedy strategy Exercise 10: Solving CliffWalking with decayed epsilon-greedy strategy Exercise 11: Multi-armed bandits Exercise 12: Creating a multi-armed bandit Exercise 13: Solving a multi-armed bandit Exercise 14: Assessing convergence in a multi-armed bandit Exercise 15: Congratulations!