npm install bayesian-bandit
node

var Bandit = require('bayesian-bandit').Bandit

<script src="https://raw.github.com/omphalos/bayesian-bandit.js/master/bayesian-bandit.js"></script>

var bandit = new Bandit({ numberOfArms: 2 })
bandit.arms[0].reward(0) // Arm 0 loses once.
bandit.arms[0].reward(1) // Arm 0 wins once.
bandit.arms[1].reward(0) // Arm 1 loses once.
bandit.arms[1].reward(1) // Arm 1 wins once.
bandit.arms[1].reward(1) // Arm 1 wins twice.
bandit.selectArm() // Arm 1 is more likely, so this probably returns 1

var bandit = new Bandit({
    arms: [{ count: 10, sum: 2 },
            { count: 20, sum: 10 },
            { count: 15: sum: 1}]
})

var bandit = new Bandit({ numberOfArms: 3 })
bandit.arms[0].rewardMultiple(10, 2)  // Arm 0 wins 2 of 10 times
bandit.arms[1].rewardMultiple(20, 10) // Arm 1 wins 10 of 20 times 
bandit.arms[2].rewardMultiple(15, 1)  // Arm 2 wins 1 of 15 times

npm install

npm test