Mengimplementasikan value iteration

Value iteration adalah metode kunci dalam RL untuk menemukan kebijakan (policy) optimal. Metode ini secara bertahap menyempurnakan fungsi nilai untuk setiap state hingga konvergen, sehingga menghasilkan penemuan kebijakan optimal. Anda akan memulai dengan fungsi nilai V dan policy yang sudah diinisialisasi dan telah dimuat untuk Anda. Selanjutnya, Anda akan memperbaruinya dalam sebuah loop hingga fungsi nilai tersebut konvergen dan melihat kebijakannya bekerja.

Fungsi get_max_action_and_value(state, V) telah dimuat untuk Anda.

Latihan ini adalah bagian dari kursus

Reinforcement Learning dengan Gymnasium di Python

Petunjuk latihan

Untuk setiap state, temukan aksi dengan nilai Q maksimum (max_action) dan nilai yang bersesuaian (max_q_value).
Perbarui kamus new_V dan policy berdasarkan max_action dan max_q_value.
Periksa konvergensi dengan memastikan selisih antara new_v dan V untuk setiap state lebih kecil daripada threshold.

Latihan interaktif praktis

Cobalah latihan ini dengan menyelesaikan kode contoh berikut.

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)

Edit dan Jalankan Kode

Latihan ini adalah bagian dari kursus

Reinforcement Learning dengan Gymnasium di Python

SkillTag.level.advancedSkillTag.label

4.8+

Mulai Kursus Gratis

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: Proses Keputusan Markov Exercise 2: Komponen MDP Frozen Lake Kustom Exercise 3: Mengeksplorasi ruang state dan aksi Exercise 4: Probabilitas transisi dan reward Exercise 5: Kebijakan dan fungsi nilai-keadaan Exercise 6: Mendefinisikan kebijakan deterministik Exercise 7: Menghitung nilai-keadaan untuk sebuah kebijakan Exercise 8: Membandingkan kebijakan Exercise 9: Fungsi nilai-aksi Exercise 10: Menghitung Nilai Q Exercise 11: Meningkatkan sebuah kebijakan Exercise 12: Iterasi kebijakan dan iterasi nilai Exercise 13: Menerapkan policy iteration untuk kebijakan optimal Exercise 14: Mengimplementasikan value iteration

Latihan Saat Ini

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!