ch.ethz.idsc.subare

Library for reinforcement learning in Java, version 0.3.8

Repository includes algorithms, examples, and exercises from the 2nd edition of Reinforcement Learning: An Introduction by Richard S. Sutton, and Andrew G. Barto.

Our implementation is inspired by the python code by Shangtong Zhang, but differs from the reference in two aspects:

• the algorithms are implemented separate from the problem scenarios
• the math is in exact precision which reproduces symmetries in the results in case the problem features symmetries

Algorithms

• Iterative Policy Evaluation (parallel, in 4.1, p.59)
• Value Iteration to determine V*(s) (parallel, in 4.4, p.65)
• Action-Value Iteration to determine Q*(s,a) (parallel)
• First Visit Policy Evaluation (in 5.1, p.74)
• Monte Carlo Exploring Starts (in 5.3, p.79)
• Contant-alpha Monte Carlo
• Tabular Temporal Difference (in 6.1, p.96)
• Sarsa: An on-policy TD control algorithm (in 6.4, p.104)
• Q-learning: An off-policy TD control algorithm (in 6.5, p.105)
• Expected Sarsa (in 6.6, p.107)
• Double Sarsa, Double Expected Sarsa, Double Q-Learning (in 6.7, p.109)
• n-step Temporal Difference for estimating V(s) (in 7.1, p.115)
• n-step Sarsa, n-step Expected Sarsa, n-step Q-Learning (in 7.2, p.118)
• Random-sample one-step tabular Q-planning (parallel, in 8.1, p.131)
• Tabular Dyna-Q (in 8.2, p.133)
• Prioritized Sweeping (in 8.4, p.137)
• Semi-gradient Tabular Temporal Difference (in 9.3, p.164)
• True Online Sarsa (in 12.8, p.309)

Gallery

Prisoner's Dilemma

Exact Gambler

Examples

4.1 Gridworld

AV-Iteration q(s,a)	TabularQPlan	Monte Carlo
Q-Learning	Expected-Sarsa	Sarsa
3-step Q-Learning	3-step E-Sarsa	3-step Sarsa
OTrue Online Sarsa	ETrue Online Sarsa	QTrue Online Sarsa

4.2: Jack's car rental

Value Iteration v(s)

4.4: Gambler's problem

Value Iteration v(s)

Action Value Iteration and optimal policy

Monte Carlo q(s,a)

ESarsa q(s,a)

QLearning q(s,a)

5.1 Blackjack

Monte Carlo Exploring Starts

5.2 Wireloop

AV-Iteration

TabularQPlan

Q-Learning

E-Sarsa

Sarsa

Monte Carlo

5.8 Racetrack

paths obtained using value iteration

track 1

track 2

6.5 Windygrid

Action Value Iteration

TabularQPlan

6.6 Cliffwalk

Action Value Iteration

Q-Learning

TabularQPlan

Expected Sarsa

8.1 Dynamaze

Action Value Iteration

Prioritized sweeping

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Additional Examples

Repeated Prisoner's dilemma

Exact expected reward of two adversarial optimistic agents depending on their initial configuration:

Exact expected reward of two adversarial Upper-Confidence-Bound agents depending on their initial configuration:

Integration

Specify dependency and repository of the tensor library in the pom.xml file of your maven project:

<dependencies>
  <dependency>
    <groupId>ch.ethz.idsc</groupId>
    <artifactId>subare</artifactId>
    <version>0.3.8</version>
  </dependency>
</dependencies>

<repositories>
  <repository>
    <id>subare-mvn-repo</id>
    <url>https://raw.github.com/idsc-frazzoli/subare/mvn-repo/</url>
    <snapshots>
      <enabled>true</enabled>
      <updatePolicy>always</updatePolicy>
    </snapshots>
  </repository>
</repositories>

The source code is attached to every release.

Contributors

Jan Hakenberg, Christian Fluri

Publications

• Learning to Operate a Fleet of Cars by Christian Fluri, Claudio Ruch, Julian Zilly, Jan Hakenberg, and Emilio Frazzoli

References

• Reinforcement Learning: An Introduction by Richard S. Sutton, and Andrew G. Barto

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