Simple multi-armed bandit algorithm implementation.
Implements several bandit algorithms (most of them found in ``Reinforcement Learning: An Introduction'' by Richard S. Sutton and Andrew G. Barto. It is available for free at http://www.incompleteideas.net/book/the-book-2nd.html).
Initialize the bandit algorithm (a few examples)
```rust // ε-greedy algorithm with 10 arms, ε=0.1, initial values of 0 let egreedy1 = EGreedy::new(10, 0.1, 0.0, UpdateType::Average));
// same ε-greedy but non-stationary with step size of 0.1 let egreedy2 = EGreedy::new(10, 0.1, 0.0, UpdateType::Nonstationary(0.1));
// Upper Confidence Bound with 10 arms and c=1 let ucb1 = UCB::new(10, 1.);
// Stochastic gradient with 10 arms, step size of 0.1, with baseline let sg1 = StochasticGradient::new(10, 0.1, true); ```
feedback loop: ```rust // choose the best action according to the bandit algorithm let action = ucb1.choose();
let reward = [...]; // using the action and computing the reward
// updates the bandit algorithm using the reward ucb1.update(action, reward); ```
Note: A more detailed example and benchmark can be found in the rl-bandit-bench crate.