[127] | 1 | package negotiator.boaframework.omstrategy;
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| 2 |
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| 3 | import java.util.HashMap;
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| 4 | import java.util.HashSet;
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| 5 | import java.util.List;
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| 6 | import java.util.Map;
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| 7 | import java.util.Random;
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| 8 | import java.util.Set;
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| 9 |
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| 10 | import genius.core.bidding.BidDetails;
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| 11 | import genius.core.boaframework.BOAparameter;
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| 12 | import genius.core.boaframework.NegotiationSession;
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| 13 | import genius.core.boaframework.OMStrategy;
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| 14 | import genius.core.boaframework.OpponentModel;
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| 15 |
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| 16 | /**
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| 17 | * This class uses an opponent model to determine the next bid for the opponent,
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| 18 | * while taking the opponent's preferences into account. The opponent model is
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| 19 | * used to select the best bid.
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| 20 | *
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| 21 | * @author Mark Hendrikx
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| 22 | */
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| 23 | public class BestBid extends OMStrategy {
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| 24 |
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| 25 | /**
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| 26 | * when to stop updating the opponentmodel. Note that this value is not
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| 27 | * exactly one as a match sometimes lasts slightly longer.
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| 28 | */
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| 29 | double updateThreshold = 1.1;
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| 30 |
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| 31 | /**
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| 32 | * Initializes the opponent model strategy. If a value for the parameter t
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| 33 | * is given, then it is set to this value. Otherwise, the default value is
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| 34 | * used.
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| 35 | *
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| 36 | * @param negotiationSession
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| 37 | * state of the negotiation.
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| 38 | * @param model
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| 39 | * opponent model used in conjunction with this opponent modeling
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| 40 | * strategy.
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| 41 | * @param parameters
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| 42 | * set of parameters for this opponent model strategy.
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| 43 | */
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| 44 | @Override
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| 45 | public void init(NegotiationSession negotiationSession, OpponentModel model, Map<String, Double> parameters) {
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| 46 | super.init(negotiationSession, model, new HashMap<String, Double>());
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| 47 | if (parameters.get("t") != null) {
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| 48 | updateThreshold = parameters.get("t").doubleValue();
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| 49 | } else {
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| 50 | System.out.println("OMStrategy assumed t = 1.1");
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| 51 | }
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| 52 | }
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| 53 |
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| 54 | /**
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| 55 | * Returns the best bid for the opponent given a set of similarly preferred
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| 56 | * bids.
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| 57 | *
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| 58 | * @param allBids
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| 59 | * of the bids considered for offering.
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| 60 | * @return bid to be offered to opponent.
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| 61 | */
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| 62 | @Override
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| 63 | public BidDetails getBid(List<BidDetails> allBids) {
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| 64 |
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| 65 | // 1. If there is only a single bid, return this bid
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| 66 | if (allBids.size() == 1) {
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| 67 | return allBids.get(0);
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| 68 | }
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| 69 | double bestUtil = -1;
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| 70 | BidDetails bestBid = allBids.get(0);
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| 71 |
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| 72 | // 2. Check that not all bids are assigned at utility of 0
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| 73 | // to ensure that the opponent model works. If the opponent model
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| 74 | // does not work, offer a random bid.
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| 75 | boolean allWereZero = true;
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| 76 | // 3. Determine the best bid
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| 77 | for (BidDetails bid : allBids) {
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| 78 | double evaluation = model.getBidEvaluation(bid.getBid());
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| 79 | if (evaluation > 0.0001) {
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| 80 | allWereZero = false;
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| 81 | }
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| 82 | if (evaluation > bestUtil) {
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| 83 | bestBid = bid;
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| 84 | bestUtil = evaluation;
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| 85 | }
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| 86 | }
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| 87 | // 4. The opponent model did not work, therefore, offer a random bid.
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| 88 | if (allWereZero) {
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| 89 | Random r = new Random();
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| 90 | return allBids.get(r.nextInt(allBids.size()));
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| 91 | }
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| 92 | return bestBid;
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| 93 | }
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| 94 |
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| 95 | /**
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| 96 | * The opponent model may be updated, unless the time is higher than a given
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| 97 | * constant.
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| 98 | *
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| 99 | * @return true if model may be updated.
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| 100 | */
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| 101 | @Override
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| 102 | public boolean canUpdateOM() {
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| 103 | return negotiationSession.getTime() < updateThreshold;
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| 104 | }
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| 105 |
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| 106 | @Override
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| 107 | public Set<BOAparameter> getParameterSpec() {
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| 108 | Set<BOAparameter> set = new HashSet<BOAparameter>();
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| 109 | set.add(new BOAparameter("t", 1.1, "Time after which the OM should not be updated"));
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| 110 | return set;
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| 111 | }
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| 112 |
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| 113 | @Override
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| 114 | public String getName() {
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| 115 | return "BestBid";
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| 116 | }
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[1] | 117 | } |
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