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README.md
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- custom-implementation
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- deep-rl-class
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model-index:
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- name:
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results:
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- task:
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type: reinforcement-learning
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type: Pixelcopter-PLE-v0
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metrics:
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- type: mean_reward
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value:
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name: mean_reward
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verified: false
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---
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# REINFORCE Agent for Pixelcopter-PLE-v0
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### Model Details
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- **Algorithm**: REINFORCE (Monte Carlo Policy Gradient)
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- **Environment**: Pixelcopter-PLE-v0 (PyGame Learning Environment)
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- **Framework**: Custom implementation following Deep RL Course guidelines
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- **Task Type**: Discrete Control (Binary Actions)
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- **Action Space**: Discrete (2 actions: do nothing or thrust up)
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- **Observation Space**: Visual/pixel-based or feature-based state representation
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### Environment Overview
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Pixelcopter-PLE-v0 is a classic helicopter control game where:
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- **Objective**: Navigate a helicopter through obstacles without crashing
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- **Challenge**: Requires precise timing and control to avoid ceiling, floor, and obstacles
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- **Physics**: Gravity constantly pulls the helicopter down; player must apply thrust to maintain altitude
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- **Scoring**: Points are awarded for surviving longer and successfully navigating through gaps
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- **Difficulty**: Requires learning temporal dependencies and precise action timing
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## Performance
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The trained REINFORCE agent achieves the following performance metrics:
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- **Mean Reward**: 13.10 ± 6.89
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- **Performance Analysis**: This represents solid performance for this challenging environment
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- **Consistency**: The standard deviation indicates moderate variability, which is expected for policy gradient methods
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### Performance Context
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The mean reward of 13.10 demonstrates that the agent has successfully learned to:
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- Navigate through multiple obstacles before crashing
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- Balance altitude control against obstacle avoidance
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- Develop timing strategies for thrust application
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- Achieve consistent survival beyond random baseline performance
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The variability (±6.89) is characteristic of policy gradient methods and reflects the stochastic nature of the learned policy, which can lead to different episode outcomes based on exploration.
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## Algorithm: REINFORCE
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REINFORCE is a foundational policy gradient algorithm that:
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- **Direct Policy Learning**: Learns a parameterized policy directly (no value function)
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- **Monte Carlo Updates**: Uses complete episode returns for policy updates
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- **Policy Gradient**: Updates policy parameters in direction of higher expected returns
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- **Stochastic Policy**: Learns probabilistic action selection for exploration
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### Key Advantages
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- Simple and intuitive policy gradient approach
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- Works well with discrete and continuous action spaces
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- No need for value function approximation
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- Good educational foundation for understanding policy gradients
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## Usage
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### Installation Requirements
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```bash
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# Core dependencies
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pip install torch torchvision
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pip install gymnasium
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pip install pygame-learning-environment
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pip install numpy matplotlib
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# For visualization and analysis
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pip install pillow
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pip install imageio # for gif creation
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```
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### Loading and Using the Model
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```python
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import torch
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import gymnasium as gym
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from ple import PLE
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from ple.games.pixelcopter import Pixelcopter
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import numpy as np
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# Load the trained model
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# Note: Adjust path based on your model file structure
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device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
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model = torch.load("pixelcopter_reinforce_model.pth", map_location=device)
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model.eval()
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# Create the environment
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def create_pixelcopter_env():
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game = Pixelcopter()
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env = PLE(game, fps=30, display=True) # Set display=False for headless
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return env
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# Initialize environment
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env = create_pixelcopter_env()
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env.init()
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# Run trained agent
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def run_agent(model, env, episodes=5):
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total_rewards = []
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for episode in range(episodes):
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env.reset_game()
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episode_reward = 0
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while not env.game_over():
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# Get current state
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state = env.getScreenRGB() # or env.getGameState() if using features
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state = preprocess_state(state) # Apply your preprocessing
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# Convert to tensor
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state_tensor = torch.FloatTensor(state).unsqueeze(0).to(device)
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# Get action probabilities
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with torch.no_grad():
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action_probs = model(state_tensor)
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action = torch.multinomial(action_probs, 1).item()
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# Execute action (0: do nothing, 1: thrust)
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reward = env.act(action)
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episode_reward += reward
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total_rewards.append(episode_reward)
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print(f"Episode {episode + 1}: Reward = {episode_reward:.2f}")
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mean_reward = np.mean(total_rewards)
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std_reward = np.std(total_rewards)
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print(f"\nAverage Performance: {mean_reward:.2f} ± {std_reward:.2f}")
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return total_rewards
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# Preprocessing function (adjust based on your model's input requirements)
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def preprocess_state(state):
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"""
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Preprocess the game state for the neural network
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This should match the preprocessing used during training
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"""
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if isinstance(state, np.ndarray) and len(state.shape) == 3:
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# If using image input
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state = np.transpose(state, (2, 0, 1)) # Channel first
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state = state / 255.0 # Normalize pixels
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return state.flatten() # or keep as image depending on model
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else:
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# If using game state features
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return np.array(list(state.values()))
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# Run the agent
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rewards = run_agent(model, env, episodes=10)
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```
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### Training Your Own Agent
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```python
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import torch
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import torch.nn as nn
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import torch.optim as optim
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import numpy as np
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from collections import deque
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class PolicyNetwork(nn.Module):
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def __init__(self, state_size, action_size, hidden_size=64):
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super(PolicyNetwork, self).__init__()
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self.fc1 = nn.Linear(state_size, hidden_size)
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self.fc2 = nn.Linear(hidden_size, hidden_size)
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self.fc3 = nn.Linear(hidden_size, action_size)
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self.softmax = nn.Softmax(dim=1)
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def forward(self, x):
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x = torch.relu(self.fc1(x))
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x = torch.relu(self.fc2(x))
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x = self.fc3(x)
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return self.softmax(x)
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class REINFORCEAgent:
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def __init__(self, state_size, action_size, lr=0.001):
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self.device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
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self.policy_net = PolicyNetwork(state_size, action_size).to(self.device)
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self.optimizer = optim.Adam(self.policy_net.parameters(), lr=lr)
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self.saved_log_probs = []
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self.rewards = []
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def select_action(self, state):
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state = torch.FloatTensor(state).unsqueeze(0).to(self.device)
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probs = self.policy_net(state)
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action = torch.multinomial(probs, 1)
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self.saved_log_probs.append(torch.log(probs.squeeze(0)[action]))
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return action.item()
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def update_policy(self, gamma=0.99):
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# Calculate discounted rewards
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discounted_rewards = []
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R = 0
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for r in reversed(self.rewards):
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R = r + gamma * R
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discounted_rewards.insert(0, R)
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# Normalize rewards
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discounted_rewards = torch.FloatTensor(discounted_rewards).to(self.device)
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discounted_rewards = (discounted_rewards - discounted_rewards.mean()) / (discounted_rewards.std() + 1e-8)
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# Calculate policy loss
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policy_loss = []
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for log_prob, reward in zip(self.saved_log_probs, discounted_rewards):
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policy_loss.append(-log_prob * reward)
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# Update policy
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self.optimizer.zero_grad()
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policy_loss = torch.cat(policy_loss).sum()
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policy_loss.backward()
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self.optimizer.step()
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# Clear episode data
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self.saved_log_probs.clear()
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self.rewards.clear()
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return policy_loss.item()
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def train_agent(episodes=2000):
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env = create_pixelcopter_env()
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env.init()
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# Determine state size based on your preprocessing
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state_size = len(preprocess_state(env.getScreenRGB())) # Adjust as needed
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action_size = 2 # do nothing, thrust
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agent = REINFORCEAgent(state_size, action_size)
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scores = deque(maxlen=100)
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for episode in range(episodes):
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env.reset_game()
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episode_reward = 0
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while not env.game_over():
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state = preprocess_state(env.getScreenRGB())
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action = agent.select_action(state)
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reward = env.act(action)
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agent.rewards.append(reward)
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episode_reward += reward
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# Update policy after each episode
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loss = agent.update_policy()
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scores.append(episode_reward)
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if episode % 100 == 0:
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avg_score = np.mean(scores)
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print(f"Episode {episode}, Average Score: {avg_score:.2f}, Loss: {loss:.4f}")
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# Save the trained model
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torch.save(agent.policy_net, "pixelcopter_reinforce_model.pth")
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return agent
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# Train a new agent
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# trained_agent = train_agent()
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```
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### Evaluation and Analysis
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```python
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import matplotlib.pyplot as plt
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def evaluate_agent_detailed(model, env, episodes=50):
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"""Detailed evaluation with statistics and visualization"""
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rewards = []
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episode_lengths = []
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for episode in range(episodes):
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env.reset_game()
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episode_reward = 0
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steps = 0
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while not env.game_over():
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state = preprocess_state(env.getScreenRGB())
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state_tensor = torch.FloatTensor(state).unsqueeze(0)
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with torch.no_grad():
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action_probs = model(state_tensor)
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action = torch.multinomial(action_probs, 1).item()
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reward = env.act(action)
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episode_reward += reward
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steps += 1
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rewards.append(episode_reward)
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episode_lengths.append(steps)
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if (episode + 1) % 10 == 0:
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print(f"Episodes {episode + 1}/{episodes} completed")
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# Statistical analysis
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mean_reward = np.mean(rewards)
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std_reward = np.std(rewards)
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median_reward = np.median(rewards)
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max_reward = np.max(rewards)
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min_reward = np.min(rewards)
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mean_length = np.mean(episode_lengths)
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print(f"\n--- Evaluation Results ---")
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print(f"Episodes: {episodes}")
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print(f"Mean Reward: {mean_reward:.2f} ± {std_reward:.2f}")
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print(f"Median Reward: {median_reward:.2f}")
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print(f"Max Reward: {max_reward:.2f}")
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print(f"Min Reward: {min_reward:.2f}")
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print(f"Mean Episode Length: {mean_length:.1f} steps")
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# Visualization
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plt.figure(figsize=(12, 4))
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plt.subplot(1, 2, 1)
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plt.plot(rewards)
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plt.axhline(y=mean_reward, color='r', linestyle='--', label=f'Mean: {mean_reward:.2f}')
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plt.title('Episode Rewards')
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plt.xlabel('Episode')
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plt.ylabel('Reward')
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plt.legend()
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plt.subplot(1, 2, 2)
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plt.hist(rewards, bins=20, alpha=0.7)
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plt.axvline(x=mean_reward, color='r', linestyle='--', label=f'Mean: {mean_reward:.2f}')
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plt.title('Reward Distribution')
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plt.xlabel('Reward')
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plt.ylabel('Frequency')
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plt.legend()
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plt.tight_layout()
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plt.show()
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return {
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'rewards': rewards,
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'episode_lengths': episode_lengths,
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'stats': {
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'mean': mean_reward,
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'std': std_reward,
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'median': median_reward,
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'max': max_reward,
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'min': min_reward
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}
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}
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# Run detailed evaluation
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# results = evaluate_agent_detailed(model, env, episodes=100)
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```
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## Training Information
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### Hyperparameters
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The REINFORCE agent was trained with carefully tuned hyperparameters:
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- **Learning Rate**: Optimized for stable policy gradient updates
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- **Discount Factor (γ)**: Balances immediate vs. future rewards
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- **Network Architecture**: Multi-layer perceptron with appropriate hidden dimensions
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- **Episode Length**: Sufficient episodes to learn temporal patterns
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### Training Environment
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- **State Representation**: Processed game screen or extracted features
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- **Action Space**: Binary discrete actions (do nothing vs. thrust)
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- **Reward Signal**: Game score progression with survival bonus
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- **Training Episodes**: Extended training to achieve stable performance
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### Algorithm Characteristics
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- **Sample Efficiency**: Moderate (typical for policy gradient methods)
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- **Stability**: Good convergence with proper hyperparameter tuning
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- **Exploration**: Built-in through stochastic policy
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- **Interpretability**: Clear policy learning through gradient ascent
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## Limitations and Considerations
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- **Sample Efficiency**: REINFORCE requires many episodes to learn effectively
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- **Variance**: Policy gradient estimates can have high variance
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- **Environment Specific**: Trained specifically for Pixelcopter game mechanics
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- **Stochastic Performance**: Episode rewards vary due to policy stochasticity
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- **Real-time Performance**: Inference speed suitable for real-time game play
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## Related Work and Extensions
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This model serves as an excellent educational example for:
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- **Policy Gradient Methods**: Understanding direct policy optimization
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- **Deep Reinforcement Learning**: Practical implementation of RL algorithms
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- **Game AI**: Learning complex temporal control tasks
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- **Baseline Comparisons**: Foundation for more advanced algorithms (A2C, PPO, etc.)
|
| 410 |
-
|
| 411 |
-
## Citation
|
| 412 |
-
|
| 413 |
-
If you use this model in your research or educational projects, please cite:
|
| 414 |
-
|
| 415 |
-
```bibtex
|
| 416 |
-
@misc{pixelcopter_reinforce_2024,
|
| 417 |
-
title={REINFORCE Agent for Pixelcopter-PLE-v0},
|
| 418 |
-
author={Adilbai},
|
| 419 |
-
year={2024},
|
| 420 |
-
publisher={Hugging Face},
|
| 421 |
-
howpublished={\url{https://huggingface.co/Adilbai/Pixelcopter-RL}},
|
| 422 |
-
note={Trained following Deep RL Course Unit 4}
|
| 423 |
-
}
|
| 424 |
-
```
|
| 425 |
-
|
| 426 |
-
## Educational Resources
|
| 427 |
-
|
| 428 |
-
This model was developed following the **Deep Reinforcement Learning Course Unit 4**:
|
| 429 |
-
- **Course Link**: [https://huggingface.co/deep-rl-course/unit4/introduction](https://huggingface.co/deep-rl-course/unit4/introduction)
|
| 430 |
-
- **Topic**: Policy Gradient Methods and REINFORCE
|
| 431 |
-
- **Learning Objectives**: Understanding policy-based RL algorithms
|
| 432 |
-
|
| 433 |
-
For comprehensive learning about REINFORCE and policy gradient methods, refer to the complete course materials.
|
| 434 |
-
|
| 435 |
-
## License
|
| 436 |
-
|
| 437 |
-
This model is distributed under the MIT License. The model is intended for educational and research purposes.
|
|
|
|
| 6 |
- custom-implementation
|
| 7 |
- deep-rl-class
|
| 8 |
model-index:
|
| 9 |
+
- name: DeepRL_pixelcopter_policy
|
| 10 |
results:
|
| 11 |
- task:
|
| 12 |
type: reinforcement-learning
|
|
|
|
| 16 |
type: Pixelcopter-PLE-v0
|
| 17 |
metrics:
|
| 18 |
- type: mean_reward
|
| 19 |
+
value: 31.50 +/- 29.61
|
| 20 |
name: mean_reward
|
| 21 |
verified: false
|
| 22 |
---
|
|
|
|
| 23 |
|
| 24 |
+
# **Reinforce** Agent playing **Pixelcopter-PLE-v0**
|
| 25 |
+
This is a trained model of a **Reinforce** agent playing **Pixelcopter-PLE-v0** .
|
| 26 |
+
To learn to use this model and train yours check Unit 4 of the Deep Reinforcement Learning Course: https://huggingface.co/deep-rl-course/unit4/introduction
|
| 27 |
+
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