qlearningupdate {QLearning}

qlearningupdate

Description

This repository implements Q-Learning, a model-free form of reinforcement learning in R.

Usage

qlearningupdate(q, currentstate, currentaction, currentreward, nextstate=NULL,
  rewardcount=.5, gamma=.25)

Arguments

q

Input state/action matrix.

currentstate

Current state of the game. Does not have to match any of the state for q.

currentaction

Action to take.

currentreward

Reward for currentaction in current iteration.

nextstate

State that the game is in after taking currentaction.

rewardcount

Regularization constant for reward.

gamma

Learning rate constant for Q-Learning.

Details

For internal use for qlearn.

Value

An updated state/action matrix.

Note

Contact at [e-mail]

Author(s)

Liam Bressler

References

http://labressler.github.io/analytics

Examples

cardgame <- function()
{
  playercards <- sample(1:8,4) #distribute the cards, we're player one
  ourcard <- playercards[1] #our card
  playertotals <- rep(-1,4) #including the antes
  playersinpot <- vector()
  for (player in 2:4) #other 3 players go first
  {
    if (playercards[player]>=2)
    {
      playertotals[player] <- (-3)
      playersinpot <- append(playersinpot,player)
    }
  }
  #the next line is where we want to choose our action
  player1 <- 'Choose'
  if (player1=="Call")
  {
    playertotals[1] <- (-3)
    playersinpot <- append(playersinpot,1)
  }
  potsize <- -1*(sum(playertotals)) #the amount in the pot is how much the players put in
  playercards[!(1:4 %in% playersinpot)] <- 0 #get rid of everyone who folded
  winner <- which.max(playercards) #winner is the person with the highest card who didn't fold
  playertotals[winner] <- playertotals[winner]+potsize
  return(playertotals[1]) #return how much we won
}

strat <- qlearn(game="cardgame",statevars="ourcard",possibleactions=c("Call","Fold"),
  playername="player1",numiter=25000) #make sure each function and variable name is a string

strat <- qlearningupdate(strat,currentstate=7,currentaction="Call",currentreward=5)
#Update the matrix after an example when we call with the 7 card as our state, winning 5 chips