Policy ağının mimarisi

Daha sonra policy gradient ajanını eğitmek için kullanabileceğin bir Policy Ağı mimarisi oluştur.

Policy ağı durumu girdi olarak alır ve eylem uzayında bir olasılık çıktılar. Lunar Lander ortamında dört ayrık eylemle çalışırsın; bu yüzden ağının bu eylemlerin her biri için birer olasılık üretmesini istersin.

Bu egzersiz, kursun bir parçasıdır

Python ile Deep Reinforcement Learning

Kursa Göz Atın

Egzersiz talimatları

Policy ağının çıktı katmanı için boyutu belirt; esneklik için gerçek sayı yerine değişken adını kullan.
Son katmanın olasılık döndürdüğünden emin ol.

Uygulamalı etkileşimli egzersiz

Bu egzersizi bu örnek kodu tamamlayarak deneyin.

class PolicyNetwork(nn.Module):
  def __init__(self, state_size, action_size):
    super(PolicyNetwork, self).__init__()
    self.fc1 = nn.Linear(state_size, 64)
    self.fc2 = nn.Linear(64, 64)
    # Give the desired size for the output layer
    self.fc3 = nn.Linear(64, ____)

  def forward(self, state):
    x = torch.relu(self.fc1(torch.tensor(state)))
    x = torch.relu(self.fc2(x))
    # Obtain the action probabilities
    action_probs = ____(self.fc3(x), dim=-1)
    return action_probs
  
policy_network = PolicyNetwork(8, 4)
action_probs = policy_network(state)
print('Action probabilities:', action_probs)

Kodu Düzenle ve Çalıştır

Bu egzersiz, kursun bir parçasıdır

Python ile Deep Reinforcement Learning

AvançadoNível de habilidade

4.8+

Kursa Ücretsiz Başla

Discover how deep reinforcement learning improves upon traditional Reinforcement Learning while studying and implementing your first Deep Q Learning algorithm.

Exercise 1: Introduction to deep reinforcement learning Exercise 2: Environment and neural network setup Exercise 3: DRL training loop Exercise 4: Introduction to deep Q learning Exercise 5: Deep learning and DQN Exercise 6: The Q-Network architecture Exercise 7: Instantiating the Q-Network Exercise 8: The barebone DQN algorithm Exercise 9: Barebone DQN action selection Exercise 10: Barebone DQN loss function Exercise 11: Training the barebone DQN

Dive into Deep Q-learning by implementing the original DQN algorithm, featuring Experience Replay, epsilon-greediness and fixed Q-targets. Beyond DQN, you will then explore two fascinating extensions that improve the performance and stability of Deep Q-learning: Double DQN and Prioritized Experience Replay.

Exercise 1: DQN with experience replay Exercise 2: The double-ended queue Exercise 3: Experience replay buffer Exercise 4: DQN with experience replay Exercise 5: The complete DQN algorithm Exercise 6: Epsilon-greediness Exercise 7: Fixed Q-targets Exercise 8: Implementing the complete DQN algorithm Exercise 9: Double DQN Exercise 10: Online network and target network in DDQN Exercise 11: Training the double DQN Exercise 12: Prioritized experience replay Exercise 13: Prioritized experience replay buffer Exercise 14: Sampling from the PER buffer Exercise 15: DQN with prioritized experience replay

Learn about the foundational concepts of policy gradient methods found in DRL. You will begin with the policy gradient theorem, which forms the basis for these methods. Then, you will implement the REINFORCE algorithm, a powerful approach to learning policies. The chapter will then guide you through Actor-Critic methods, focusing on the Advantage Actor-Critic (A2C) algorithm, which combines the strengths of both policy gradient and value-based methods to enhance learning efficiency and stability.

Exercise 1: Politika gradyanına giriş Exercise 2: Policy ağının mimarisi

Geçerli egzersiz

Exercise 3: Ayrık dağılımlarla çalışmak Exercise 4: Policy gradient ve REINFORCE Exercise 5: REINFORCE'ta eylem seçimi Exercise 6: REINFORCE algoritmasını eğitme Exercise 7: Advantage Actor-Critic Exercise 8: Eleştirmen (Critic) ağı Exercise 9: Actor-Critic kayıp hesaplamaları Exercise 10: A2C algoritmasını eğitme

Explore Proximal Policy Optimization (PPO) for robust DRL performance. Next, you will examine using an entropy bonus in PPO, which encourages exploration by preventing premature convergence to deterministic policies. You'll also learn about batch updates in policy gradient methods. Finally, you will learn about hyperparameter optimization with Optuna, a powerful tool for optimizing performance in your DRL models.

Exercise 1: Proximal policy optimization Exercise 2: The clipped probability ratio Exercise 3: The clipped surrogate objective function Exercise 4: Entropy bonus and PPO Exercise 5: Entropy playground Exercise 6: Training the PPO algorithm Exercise 7: Batch updates in policy gradient Exercise 8: Minibatch and DRL Exercise 9: A2C with batch updates Exercise 10: Hyperparameter optimization with Optuna Exercise 11: Hyperparameter or not?Exercise 12: Hands-on with Optuna Exercise 13: Congratulations!