[127] | 1 | package agents.anac.y2010.Yushu;
|
---|
| 2 |
|
---|
| 3 | import java.util.HashMap;
|
---|
| 4 | import java.util.List;
|
---|
| 5 | import java.util.Random;
|
---|
| 6 |
|
---|
| 7 | import genius.core.Agent;
|
---|
| 8 | import genius.core.Bid;
|
---|
| 9 | import genius.core.actions.Accept;
|
---|
| 10 | import genius.core.actions.Action;
|
---|
| 11 | import genius.core.actions.Offer;
|
---|
| 12 | import genius.core.issue.Issue;
|
---|
| 13 | import genius.core.issue.IssueDiscrete;
|
---|
| 14 | import genius.core.issue.IssueInteger;
|
---|
| 15 | import genius.core.issue.IssueReal;
|
---|
| 16 | import genius.core.issue.Value;
|
---|
| 17 | import genius.core.issue.ValueInteger;
|
---|
| 18 | import genius.core.issue.ValueReal;
|
---|
| 19 | import genius.core.utility.AdditiveUtilitySpace;
|
---|
| 20 |
|
---|
| 21 | public class Utility {
|
---|
| 22 | static double MINIMUM_BID_UTILITY = 0.95;
|
---|
| 23 |
|
---|
| 24 | /**
|
---|
| 25 | * Wrapper for getRandomBid, for convenience.
|
---|
| 26 | *
|
---|
| 27 | * @param lastOppBid
|
---|
| 28 | * the last opponent bid that was received.
|
---|
| 29 | * @return new Action(Bid(..)), with bid utility > MINIMUM_BID_UTIL. If a
|
---|
| 30 | * problem occurs, it returns an Accept() action.
|
---|
| 31 | */
|
---|
| 32 | public static Action chooseRandomBidAction(Agent agent, Bid lastOppBid) {
|
---|
| 33 | Bid nextBid = null;
|
---|
| 34 | try {
|
---|
| 35 | nextBid = Utility
|
---|
| 36 | .getRandomBid((AdditiveUtilitySpace) agent.utilitySpace);
|
---|
| 37 | } catch (Exception e) {
|
---|
| 38 | e.printStackTrace();
|
---|
| 39 | }
|
---|
| 40 | if (nextBid == null)
|
---|
| 41 | return (new Accept(agent.getAgentID(), lastOppBid));
|
---|
| 42 | return (new Offer(agent.getAgentID(), nextBid));
|
---|
| 43 | }
|
---|
| 44 |
|
---|
| 45 | /**
|
---|
| 46 | * @return a random bid with high enough utility value.
|
---|
| 47 | * @throws Exception
|
---|
| 48 | * if we can't compute the utility (eg no evaluators have been
|
---|
| 49 | * set) or when other evaluators than a DiscreteEvaluator are
|
---|
| 50 | * present in the util space.
|
---|
| 51 | */
|
---|
| 52 | public static Bid getRandomBid(AdditiveUtilitySpace utilityspace)
|
---|
| 53 | throws Exception {
|
---|
| 54 | HashMap<Integer, Value> values = new HashMap<Integer, Value>(); // pairs
|
---|
| 55 | // <issuenumber,chosen
|
---|
| 56 | // value
|
---|
| 57 | // string>
|
---|
| 58 | List<Issue> issues = utilityspace.getDomain().getIssues();
|
---|
| 59 | Random randomnr = new Random();
|
---|
| 60 | // createFrom a random bid with utility>MINIMUM_BID_UTIL.
|
---|
| 61 | // note that this may never succeed if you set MINIMUM too high!!!
|
---|
| 62 | // in that case we will search for a bid till the time is up (2 minutes)
|
---|
| 63 | // but this is just a simple agent.
|
---|
| 64 | Bid bid = null;
|
---|
| 65 | do {
|
---|
| 66 |
|
---|
| 67 | for (Issue lIssue : issues) {
|
---|
| 68 | switch (lIssue.getType()) {
|
---|
| 69 | case DISCRETE:
|
---|
| 70 | IssueDiscrete lIssueDiscrete = (IssueDiscrete) lIssue;
|
---|
| 71 | int optionIndex = randomnr.nextInt(lIssueDiscrete
|
---|
| 72 | .getNumberOfValues());
|
---|
| 73 | values.put(lIssue.getNumber(),
|
---|
| 74 | lIssueDiscrete.getValue(optionIndex));
|
---|
| 75 | break;
|
---|
| 76 | case REAL:
|
---|
| 77 | IssueReal lIssueReal = (IssueReal) lIssue;
|
---|
| 78 | int optionInd = randomnr.nextInt(lIssueReal
|
---|
| 79 | .getNumberOfDiscretizationSteps() - 1);
|
---|
| 80 | values.put(
|
---|
| 81 | lIssueReal.getNumber(),
|
---|
| 82 | new ValueReal(lIssueReal.getLowerBound()
|
---|
| 83 | + (lIssueReal.getUpperBound() - lIssueReal
|
---|
| 84 | .getLowerBound())
|
---|
| 85 | * (double) (optionInd)
|
---|
| 86 | / (double) (lIssueReal
|
---|
| 87 | .getNumberOfDiscretizationSteps())));
|
---|
| 88 | break;
|
---|
| 89 | case INTEGER:
|
---|
| 90 | IssueInteger lIssueInteger = (IssueInteger) lIssue;
|
---|
| 91 | int optionIndex2 = lIssueInteger.getLowerBound()
|
---|
| 92 | + randomnr.nextInt(lIssueInteger.getUpperBound()
|
---|
| 93 | - lIssueInteger.getLowerBound());
|
---|
| 94 | values.put(lIssueInteger.getNumber(), new ValueInteger(
|
---|
| 95 | optionIndex2));
|
---|
| 96 | break;
|
---|
| 97 | default:
|
---|
| 98 | throw new Exception("issue type " + lIssue.getType()
|
---|
| 99 | + " not supported by SimpleAgent2");
|
---|
| 100 | }
|
---|
| 101 | }
|
---|
| 102 | bid = new Bid(utilityspace.getDomain(), values);
|
---|
| 103 | } while (utilityspace.getUtility(bid) < MINIMUM_BID_UTILITY);
|
---|
| 104 |
|
---|
| 105 | return bid;
|
---|
| 106 | }
|
---|
| 107 |
|
---|
| 108 | /**
|
---|
| 109 | * This function determines the accept probability for an offer. At t=0 it
|
---|
| 110 | * will prefer high-utility offers. As t gets closer to 1, it will accept
|
---|
| 111 | * lower utility offers with increasing probability. it will never accept
|
---|
| 112 | * offers with utility 0.
|
---|
| 113 | *
|
---|
| 114 | * @param u
|
---|
| 115 | * is the utility
|
---|
| 116 | * @param t
|
---|
| 117 | * is the time as fraction of the total available time (t=0 at
|
---|
| 118 | * start, and t=1 at end time)
|
---|
| 119 | * @return the probability of an accept at time t
|
---|
| 120 | * @throws Exception
|
---|
| 121 | * if you use wrong values for u or t.
|
---|
| 122 | *
|
---|
| 123 | */
|
---|
| 124 | public static double Paccept(double u, double t1) throws Exception {
|
---|
| 125 | double t = t1 * t1 * t1; // steeper increase when deadline approaches.
|
---|
| 126 | if (u < 0 || u > 1.05)
|
---|
| 127 | throw new Exception("utility " + u + " outside [0,1]");
|
---|
| 128 | // normalization may be slightly off, therefore we have a broad boundary
|
---|
| 129 | // up to 1.05
|
---|
| 130 | if (t < 0 || t > 1)
|
---|
| 131 | throw new Exception("time " + t + " outside [0,1]");
|
---|
| 132 | if (u > 1.)
|
---|
| 133 | u = 1;
|
---|
| 134 | if (t == 0.5)
|
---|
| 135 | return u;
|
---|
| 136 | return (u - 2. * u * t + 2. * (-1. + t + Math.sqrt(sq(-1. + t) + u
|
---|
| 137 | * (-1. + 2 * t))))
|
---|
| 138 | / (-1. + 2 * t);
|
---|
| 139 | }
|
---|
| 140 |
|
---|
| 141 | public static double sq(double x) {
|
---|
| 142 | return x * x;
|
---|
| 143 | }
|
---|
| 144 |
|
---|
| 145 | }
|
---|