This repository implements several algorithms:

• Trust Region Policy Optimization [1]
• Proximal Policy Optimization (i.e., TRPO, but using a penalty instead of a constraint on KL divergence), where each subproblem is solved with either SGD or L-BFGS
• Cross Entropy Method

TRPO and PPO are implemented with neural-network value functions and use GAE [2].

This library is written in a modular way to allow for sharing code between TRPO and PPO variants, and to write the same code for different kinds of action spaces.

Dependencies:

• keras (2.0.2)
• theano (0.9.0)
• tabulate
• numpy
• scipy

To run the algorithms implemented here, you should put modular_rl on your PYTHONPATH, or run the scripts (e.g. run_pg.py) from this directory.

Good parameter settings can be found in the experiments directory.

You can learn about the various parameters by running one of the experiment scripts with the -h flag, but providing the (required) env and agent parameters. (Those parameters determine what other parameters are available.) For example, to see the parameters of TRPO,

./run_pg.py --env CartPole-v0 --agent modular_rl.agentzoo.TrpoAgent -h

To the the parameters of CEM,

./run_cem.py --env=Acrobot-v0 --agent=modular_rl.agentzoo.DeterministicAgent  --n_iter=2

[1] JS, S Levine, P Moritz, M Jordan, P Abbeel, "Trust region policy optimization." arXiv preprint arXiv:1502.05477 (2015).

[2] JS, P Moritz, S Levine, M Jordan, P Abbeel, "High-dimensional continuous control using generalized advantage estimation." arXiv preprint arXiv:1506.02438 (2015).