Serendipity
d353133b31
- 新增强化学习个人项目报告，包含基于PyTorch从零实现的PPO算法 - 重构课程作业报告代码结构，提取运行时路径管理和notebook执行逻辑到独立模块 - 更新依赖文件requirements.txt，添加强化学习相关依赖 - 简化模型比较结果表格，仅保留基线逻辑回归模型数据
PPO for CarRacing-v3
From-scratch PPO implementation for CarRacing-v3. No Stable-Baselines or other RL libraries used.
Setup
conda activate my_env
uv pip install -r requirements.txt
Train
python train.py --steps 500000
Evaluate
python src/evaluate.py --model models/ppo_carracing_final.pt --episodes 10
TensorBoard
tensorboard --logdir logs/tensorboard
Project Structure
src/
├── network.py # Actor (Gaussian policy) and Critic (Value) networks
├── replay_buffer.py # Rollout buffer with GAE computation
├── trainer.py # PPO update with clipped surrogate objective
├── utils.py # Environment wrappers (grayscale, resize, frame stack)
└── evaluate.py # Evaluation script
train.py # Main training entry point
models/ # Saved checkpoints
logs/tensorboard/ # TensorBoard logs
Hyperparameters
| Parameter | Value |
|---|---|
| Learning rate | 3e-4 |
| Gamma | 0.99 |
| GAE lambda | 0.95 |
| Clip epsilon | 0.2 |
| PPO epochs | 4 |
| Mini-batch size | 64 |
| Rollout steps | 2048 |
| Entropy coefficient | 0.01 |
| Value coefficient | 0.5 |
| Max gradient norm | 0.5 |