[126] | 1 | package agents;
|
---|
| 2 |
|
---|
| 3 | import java.util.ArrayList;
|
---|
| 4 |
|
---|
| 5 | import agents.bayesianopponentmodel.BayesianOpponentModel;
|
---|
| 6 | import agents.bayesianopponentmodel.OpponentModel;
|
---|
| 7 | import agents.bayesianopponentmodel.OpponentModelUtilSpace;
|
---|
| 8 | import genius.core.Agent;
|
---|
| 9 | import genius.core.AgentParam;
|
---|
| 10 | import genius.core.Bid;
|
---|
| 11 | import genius.core.BidIterator;
|
---|
| 12 | import genius.core.actions.Accept;
|
---|
| 13 | import genius.core.actions.Action;
|
---|
| 14 | import genius.core.actions.EndNegotiation;
|
---|
| 15 | import genius.core.actions.Offer;
|
---|
| 16 | import genius.core.analysis.BidPoint;
|
---|
| 17 | import genius.core.analysis.BidSpace;
|
---|
| 18 | import genius.core.tournament.VariablesAndValues.AgentParameterVariable;
|
---|
| 19 | import genius.core.utility.AdditiveUtilitySpace;
|
---|
| 20 |
|
---|
| 21 | /**
|
---|
| 22 | * Wrapper for opponentmodelspace, so that it is a neat utilityspace that we can
|
---|
| 23 | * give to the bidspace.
|
---|
| 24 | *
|
---|
| 25 | * @author wouter
|
---|
| 26 | *
|
---|
| 27 | */
|
---|
| 28 |
|
---|
| 29 | public class BayesianAgentForAuction extends Agent {
|
---|
| 30 |
|
---|
| 31 | protected Action messageOpponent;
|
---|
| 32 | protected Bid myLastBid = null;
|
---|
| 33 | protected Action myLastAction = null;
|
---|
| 34 | protected Bid fOpponentPreviousBid = null;
|
---|
| 35 |
|
---|
| 36 | protected enum ROLE {
|
---|
| 37 | CENTER, PROVIDER, IRRELEVANT
|
---|
| 38 | };
|
---|
| 39 |
|
---|
| 40 | public enum PHASE {
|
---|
| 41 | FIRST_PHASE, SECOND_PHASE
|
---|
| 42 | };
|
---|
| 43 |
|
---|
| 44 | protected enum ACTIONTYPE {
|
---|
| 45 | START, OFFER, ACCEPT, BREAKOFF
|
---|
| 46 | };
|
---|
| 47 |
|
---|
| 48 | private enum STRATEGY {
|
---|
| 49 | SMART, SERIAL, RESPONSIVE, RANDOM, TIT_FOR_TAT, AUCTION
|
---|
| 50 | };
|
---|
| 51 |
|
---|
| 52 | private STRATEGY fStrategy = STRATEGY.AUCTION;
|
---|
| 53 | private boolean fMarketPreassure = false;
|
---|
| 54 | protected int fSmartSteps;
|
---|
| 55 | protected OpponentModel fOpponentModel;
|
---|
| 56 | protected OpponentModel[] fOpponentModels = null;
|
---|
| 57 | protected double CONCESSIONFACTOR = 0.04;
|
---|
| 58 | private static final double ALLOWED_UTILITY_DEVIATION = 0.01;
|
---|
| 59 | protected static final int NUMBER_OF_SMART_STEPS = 0;
|
---|
| 60 | protected ArrayList<Bid> myPreviousBids;
|
---|
| 61 | private boolean fDebug = false;
|
---|
| 62 | protected PHASE fPhase = null;
|
---|
| 63 | protected ROLE fRole;
|
---|
| 64 |
|
---|
| 65 | // Class constructor
|
---|
| 66 | public BayesianAgentForAuction() {
|
---|
| 67 | super();
|
---|
| 68 |
|
---|
| 69 | }
|
---|
| 70 |
|
---|
| 71 | @Override
|
---|
| 72 | public String getVersion() {
|
---|
| 73 | return "2.0";
|
---|
| 74 | }
|
---|
| 75 |
|
---|
| 76 | /** Dummy variables, for testing only. W.Pasman 19aug08 */
|
---|
| 77 | public static ArrayList<AgentParam> getParameters() {
|
---|
| 78 | ArrayList<AgentParam> parameters = new ArrayList<AgentParam>();
|
---|
| 79 | parameters.add(new AgentParam(BayesianAgentForAuction.class.getName(),
|
---|
| 80 | "reservation", 0., 1.));
|
---|
| 81 | parameters.add(new AgentParam(BayesianAgentForAuction.class.getName(),
|
---|
| 82 | "starting_utility", 0., 1.));
|
---|
| 83 | parameters.add(new AgentParam(BayesianAgentForAuction.class.getName(),
|
---|
| 84 | "role", -1., 3.));
|
---|
| 85 | parameters.add(new AgentParam(BayesianAgentForAuction.class.getName(),
|
---|
| 86 | "phase", -1., 1.));
|
---|
| 87 | parameters.add(new AgentParam(BayesianAgentForAuction.class.getName(),
|
---|
| 88 | "opponent", -1., 1.));
|
---|
| 89 | return parameters;
|
---|
| 90 | }
|
---|
| 91 |
|
---|
| 92 | public void init() {
|
---|
| 93 | messageOpponent = null;
|
---|
| 94 | myLastAction = null;
|
---|
| 95 | fSmartSteps = 0;
|
---|
| 96 | myPreviousBids = new ArrayList<Bid>();
|
---|
| 97 | fOpponentPreviousBid = null;
|
---|
| 98 | if ((getParameterValues().isEmpty())
|
---|
| 99 | || (getParameterValues().get(
|
---|
| 100 | new AgentParameterVariable(new AgentParam(
|
---|
| 101 | BayesianAgentForAuction.class.getName(),
|
---|
| 102 | "phase", new Double(-1.), new Double(1.))))
|
---|
| 103 | .getValue() < 0))
|
---|
| 104 | fPhase = PHASE.FIRST_PHASE;
|
---|
| 105 | else
|
---|
| 106 | fPhase = PHASE.SECOND_PHASE;
|
---|
| 107 | if (getParameterValues().isEmpty())
|
---|
| 108 | fRole = ROLE.IRRELEVANT;
|
---|
| 109 | else if ((getParameterValues().get(
|
---|
| 110 | new AgentParameterVariable(new AgentParam(
|
---|
| 111 | BayesianAgentForAuction.class.getName(), "role", -1.,
|
---|
| 112 | 3.))).getValue() < 0))
|
---|
| 113 | fRole = ROLE.PROVIDER;
|
---|
| 114 | else if (getParameterValues().get(
|
---|
| 115 | new AgentParameterVariable(new AgentParam(
|
---|
| 116 | BayesianAgentForAuction.class.getName(), "role", -1.,
|
---|
| 117 | 3.))).getValue() < 2) {
|
---|
| 118 | fRole = ROLE.CENTER;
|
---|
| 119 | CONCESSIONFACTOR = 0.06;
|
---|
| 120 | } else
|
---|
| 121 | fRole = ROLE.IRRELEVANT;
|
---|
| 122 | if ((fPhase == PHASE.FIRST_PHASE) && (fOpponentModels == null))
|
---|
| 123 | prepareOpponentModel();
|
---|
| 124 | if (fRole == ROLE.CENTER) {
|
---|
| 125 | int index = Double.valueOf(
|
---|
| 126 | getParameterValues().get(
|
---|
| 127 | new AgentParameterVariable(new AgentParam(
|
---|
| 128 | BayesianAgentForAuction.class.getName(),
|
---|
| 129 | "opponent", -1., 1.))).getValue())
|
---|
| 130 | .intValue();
|
---|
| 131 | fOpponentModel = fOpponentModels[index];
|
---|
| 132 | }
|
---|
| 133 |
|
---|
| 134 | }
|
---|
| 135 |
|
---|
| 136 | protected void prepareOpponentModel() {
|
---|
| 137 | fOpponentModels = new BayesianOpponentModel[2];
|
---|
| 138 | fOpponentModels[0] = new BayesianOpponentModel(
|
---|
| 139 | (AdditiveUtilitySpace) utilitySpace);
|
---|
| 140 | fOpponentModels[1] = new BayesianOpponentModel(
|
---|
| 141 | (AdditiveUtilitySpace) utilitySpace);
|
---|
| 142 | fOpponentModel = fOpponentModels[0];
|
---|
| 143 | }
|
---|
| 144 |
|
---|
| 145 | // Class methods
|
---|
| 146 | public void ReceiveMessage(Action opponentAction) {
|
---|
| 147 | messageOpponent = opponentAction;
|
---|
| 148 | }
|
---|
| 149 |
|
---|
| 150 | protected Action proposeInitialBid() throws Exception {
|
---|
| 151 | Bid lBid = null;
|
---|
| 152 | switch (fRole) {
|
---|
| 153 | case CENTER:
|
---|
| 154 | switch (fPhase) {
|
---|
| 155 | case FIRST_PHASE:
|
---|
| 156 | lBid = getMaxUtilityBid();
|
---|
| 157 | break;
|
---|
| 158 | case SECOND_PHASE:
|
---|
| 159 | double lSecondBest = getParameterValues().get(
|
---|
| 160 | new AgentParameterVariable(new AgentParam(
|
---|
| 161 | BayesianAgentForAuction.class.getName(),
|
---|
| 162 | "reservation", 0., 1.))).getValue();
|
---|
| 163 | lBid = getTradeOff(lSecondBest);
|
---|
| 164 | break;
|
---|
| 165 | }
|
---|
| 166 | break;
|
---|
| 167 | case PROVIDER:
|
---|
| 168 | switch (fPhase) {
|
---|
| 169 | case FIRST_PHASE:
|
---|
| 170 | double lReservationValue = utilitySpace.getReservationValue();// parametervalues.get("reservation");
|
---|
| 171 | lBid = getTradeOff(lReservationValue);
|
---|
| 172 | break;
|
---|
| 173 | case SECOND_PHASE:
|
---|
| 174 | lBid = getMaxUtilityBid();
|
---|
| 175 | break;
|
---|
| 176 | }
|
---|
| 177 | break;
|
---|
| 178 | case IRRELEVANT:
|
---|
| 179 | switch (fPhase) {
|
---|
| 180 | case FIRST_PHASE:
|
---|
| 181 | // if(fRole=ROLE.)
|
---|
| 182 | lBid = getMaxUtilityBid();
|
---|
| 183 | break;
|
---|
| 184 | case SECOND_PHASE:
|
---|
| 185 | double lSecondBest = getParameterValues().get(
|
---|
| 186 | new AgentParameterVariable(new AgentParam(
|
---|
| 187 | BayesianAgentForAuction.class.getName(),
|
---|
| 188 | "starting_utility", 0., 1.))).getValue();
|
---|
| 189 | lBid = getTradeOff(lSecondBest);
|
---|
| 190 | break;
|
---|
| 191 | }
|
---|
| 192 | break;
|
---|
| 193 | }
|
---|
| 194 | // Return (one of the) possible bid(s) with maximal utility.
|
---|
| 195 | fSmartSteps = NUMBER_OF_SMART_STEPS;
|
---|
| 196 | myLastBid = lBid;
|
---|
| 197 | return new Offer(getAgentID(), lBid);
|
---|
| 198 | }
|
---|
| 199 |
|
---|
| 200 | /**
|
---|
| 201 | *
|
---|
| 202 | * @param pOppntBid
|
---|
| 203 | * @return a counterbid that has max util for us and an opponent utility
|
---|
| 204 | * that is equal to 1-estimated utility of opponent's last bid. Or,
|
---|
| 205 | * if that bid was done already before, another bid that has same
|
---|
| 206 | * utility in our space as that counterbid.
|
---|
| 207 | * @throws Exception
|
---|
| 208 | */
|
---|
| 209 | protected Bid getNextBidAuction(Bid pOppntBid) throws Exception {
|
---|
| 210 | if (pOppntBid == null)
|
---|
| 211 | throw new NullPointerException("pOpptBid=null");
|
---|
| 212 | if (myLastBid == null)
|
---|
| 213 | throw new Exception("myLastBid==null");
|
---|
| 214 | log("Get next bid ...");
|
---|
| 215 | Bid lBid = null;
|
---|
| 216 |
|
---|
| 217 | switch (fRole) {
|
---|
| 218 | case CENTER:
|
---|
| 219 | switch (fPhase) {
|
---|
| 220 | case FIRST_PHASE:
|
---|
| 221 | lBid = getNextBidSmart(pOppntBid);
|
---|
| 222 | break;
|
---|
| 223 | case SECOND_PHASE:
|
---|
| 224 | double lSecondBest = getParameterValues().get(
|
---|
| 225 | new AgentParameterVariable(new AgentParam(
|
---|
| 226 | BayesianAgentForAuction.class.getName(),
|
---|
| 227 | "reservation", 0., 1.))).getValue();
|
---|
| 228 | lBid = getTradeOff(lSecondBest);
|
---|
| 229 | break;
|
---|
| 230 | }
|
---|
| 231 | break;
|
---|
| 232 | case PROVIDER:
|
---|
| 233 | switch (fPhase) {
|
---|
| 234 | case FIRST_PHASE:
|
---|
| 235 | double lReservationValue = utilitySpace.getReservationValue();// parametervalues.get("reservation");
|
---|
| 236 | lBid = getTradeOff(lReservationValue);
|
---|
| 237 | break;
|
---|
| 238 | case SECOND_PHASE:
|
---|
| 239 | lBid = getNextBidSmart(pOppntBid);
|
---|
| 240 | break;
|
---|
| 241 | }
|
---|
| 242 | break;
|
---|
| 243 | case IRRELEVANT:
|
---|
| 244 | switch (fPhase) {
|
---|
| 245 | case FIRST_PHASE:
|
---|
| 246 | lBid = getNextBidSmart(pOppntBid);
|
---|
| 247 | break;
|
---|
| 248 | case SECOND_PHASE:
|
---|
| 249 | lBid = getNextBidSmart(pOppntBid);
|
---|
| 250 | break;
|
---|
| 251 | }
|
---|
| 252 | break;
|
---|
| 253 |
|
---|
| 254 | }
|
---|
| 255 | return lBid;
|
---|
| 256 | }
|
---|
| 257 |
|
---|
| 258 | /**
|
---|
| 259 | *
|
---|
| 260 | * @param pOppntBid
|
---|
| 261 | * @return a counterbid that has max util for us and an opponent utility
|
---|
| 262 | * that is equal to 1-estimated utility of opponent's last bid. Or,
|
---|
| 263 | * if that bid was done already before, another bid that has same
|
---|
| 264 | * utility in our space as that counterbid.
|
---|
| 265 | * @throws Exception
|
---|
| 266 | */
|
---|
| 267 | private Bid getNextBid(Bid pOppntBid) throws Exception {
|
---|
| 268 | if (pOppntBid == null)
|
---|
| 269 | throw new NullPointerException("pOpptBid=null");
|
---|
| 270 | if (myLastBid == null)
|
---|
| 271 | throw new Exception("myLastBid==null");
|
---|
| 272 | log("Get next bid ...");
|
---|
| 273 |
|
---|
| 274 | BidSpace bs = new BidSpace((AdditiveUtilitySpace) utilitySpace,
|
---|
| 275 | new OpponentModelUtilSpace(fOpponentModel), true, true);
|
---|
| 276 | // System.out.println("Bidspace:\n"+bs);
|
---|
| 277 |
|
---|
| 278 | // compute opponent's concession
|
---|
| 279 | double opponentConcession = 0.;
|
---|
| 280 | if (fOpponentPreviousBid == null)
|
---|
| 281 | opponentConcession = 0;
|
---|
| 282 | else {
|
---|
| 283 | double opponentUtil = fOpponentModel
|
---|
| 284 | .getNormalizedUtility(pOppntBid);
|
---|
| 285 | double opponentFirstBidUtil = fOpponentModel
|
---|
| 286 | .getNormalizedUtility(fOpponentModel.fBiddingHistory.get(0));
|
---|
| 287 | opponentConcession = opponentUtil - opponentFirstBidUtil;
|
---|
| 288 | }
|
---|
| 289 | log("opponent Concession:" + opponentConcession);
|
---|
| 290 |
|
---|
| 291 | // determine our bid point
|
---|
| 292 | double OurFirstBidOppUtil = fOpponentModel
|
---|
| 293 | .getNormalizedUtility(myPreviousBids.get(0));
|
---|
| 294 | double OurTargetBidOppUtil = OurFirstBidOppUtil - opponentConcession;
|
---|
| 295 | if (OurTargetBidOppUtil > 1)
|
---|
| 296 | OurTargetBidOppUtil = 1.;
|
---|
| 297 | if (OurTargetBidOppUtil < OurFirstBidOppUtil)
|
---|
| 298 | OurTargetBidOppUtil = OurFirstBidOppUtil;
|
---|
| 299 | log("our target opponent utility=" + OurTargetBidOppUtil);
|
---|
| 300 |
|
---|
| 301 | // find the target on the pareto curve
|
---|
| 302 | double targetUtil = bs.ourUtilityOnPareto(OurTargetBidOppUtil);
|
---|
| 303 |
|
---|
| 304 | BidPoint bp = bs.getNearestBidPoint(targetUtil, OurTargetBidOppUtil,
|
---|
| 305 | .5, 1, myPreviousBids);
|
---|
| 306 | log("found bid " + bp);
|
---|
| 307 | return bp.getBid();
|
---|
| 308 | }
|
---|
| 309 |
|
---|
| 310 | /**
|
---|
| 311 | * get a new bid (not done before) that has ourUtility for us.
|
---|
| 312 | *
|
---|
| 313 | * @param ourUtility
|
---|
| 314 | * @return the bid with max opponent utility that is close to ourUtility. or
|
---|
| 315 | * null if there is no such bid.
|
---|
| 316 | */
|
---|
| 317 | Bid getNewBidWithUtil(double ourUtility, BidSpace bs) {
|
---|
| 318 | BidPoint bestbid = null;
|
---|
| 319 | double bestbidutil = 0;
|
---|
| 320 | for (BidPoint p : bs.bidPoints) {
|
---|
| 321 | if (Math.abs(ourUtility - p.getUtilityA()) < ALLOWED_UTILITY_DEVIATION
|
---|
| 322 | && p.getUtilityB() > bestbidutil
|
---|
| 323 | && !myPreviousBids.contains(p.getBid())) {
|
---|
| 324 | bestbid = p;
|
---|
| 325 | bestbidutil = p.getUtilityB();
|
---|
| 326 | }
|
---|
| 327 | }
|
---|
| 328 | if (bestbid == null)
|
---|
| 329 | return null;
|
---|
| 330 | return bestbid.getBid();
|
---|
| 331 | }
|
---|
| 332 |
|
---|
| 333 | /**
|
---|
| 334 | * Wouter: Try to find a bid that has same utility for ourself but max
|
---|
| 335 | * utility for opponent.
|
---|
| 336 | *
|
---|
| 337 | * @author Dmytro
|
---|
| 338 | * @param pBid
|
---|
| 339 | * @return
|
---|
| 340 | * @throws Exception
|
---|
| 341 | */
|
---|
| 342 | protected Bid getSmartBid(Bid pBid) throws Exception {
|
---|
| 343 | Bid lBid = null;
|
---|
| 344 | double lExpectedUtility = -1;
|
---|
| 345 | double lUtility = utilitySpace.getUtility(pBid);
|
---|
| 346 | BidIterator lIter = new BidIterator(utilitySpace.getDomain());
|
---|
| 347 | // int i=1;
|
---|
| 348 | while (lIter.hasNext()) {
|
---|
| 349 | Bid tmpBid = lIter.next();
|
---|
| 350 | // System.out.println(tmpBid);
|
---|
| 351 | // System.out.println(String.valueOf(i++));
|
---|
| 352 | if (Math.abs(utilitySpace.getUtility(tmpBid) - lUtility) < ALLOWED_UTILITY_DEVIATION) {
|
---|
| 353 | // double lTmpSim = fSimilarity.getSimilarity(tmpBid,
|
---|
| 354 | // pOppntBid);
|
---|
| 355 | double lTmpExpecteUtility = fOpponentModel
|
---|
| 356 | .getNormalizedUtility(tmpBid);
|
---|
| 357 | if (lTmpExpecteUtility > lExpectedUtility) {
|
---|
| 358 | lExpectedUtility = lTmpExpecteUtility;
|
---|
| 359 | lBid = tmpBid;
|
---|
| 360 | }
|
---|
| 361 | }
|
---|
| 362 | }
|
---|
| 363 | return lBid;
|
---|
| 364 | // check if really found a better bid. if not return null
|
---|
| 365 | /*
|
---|
| 366 | * if(fOpponentModel.getNormalizedUtility(lBid)>(fOpponentModel.
|
---|
| 367 | * getNormalizedUtility(pBid)+0.04)) return lBid; else return null;
|
---|
| 368 | */
|
---|
| 369 | }
|
---|
| 370 |
|
---|
| 371 | protected Bid getNextBidSmart(Bid pOppntBid) throws Exception {
|
---|
| 372 | double lMyUtility, lOppntUtility, lTargetUtility;
|
---|
| 373 | // Both parties have made an initial bid. Compute associated utilities
|
---|
| 374 | // from my point of view.
|
---|
| 375 | lMyUtility = utilitySpace.getUtility(myLastBid);
|
---|
| 376 | lOppntUtility = utilitySpace.getUtility(pOppntBid);
|
---|
| 377 | if (fSmartSteps >= NUMBER_OF_SMART_STEPS) {
|
---|
| 378 | lTargetUtility = getTargetUtility(lMyUtility, lOppntUtility);
|
---|
| 379 | fSmartSteps = 0;
|
---|
| 380 | } else {
|
---|
| 381 | lTargetUtility = lMyUtility;
|
---|
| 382 | fSmartSteps++;
|
---|
| 383 | }
|
---|
| 384 | if (lTargetUtility < utilitySpace.getReservationValue())
|
---|
| 385 | return null;
|
---|
| 386 | else
|
---|
| 387 | return getTradeOff(lTargetUtility);
|
---|
| 388 | }
|
---|
| 389 |
|
---|
| 390 | protected Bid getTradeOff(double pUtility) throws Exception {
|
---|
| 391 | if (pUtility < utilitySpace.getReservationValue())
|
---|
| 392 | return null;
|
---|
| 393 | Bid lBid = null;
|
---|
| 394 | double lExpectedUtility = -100;
|
---|
| 395 | BidIterator lIter = new BidIterator(utilitySpace.getDomain());
|
---|
| 396 | // int i=1;
|
---|
| 397 | while (lIter.hasNext()) {
|
---|
| 398 | Bid tmpBid = lIter.next();
|
---|
| 399 | // System.out.println(tmpBid);
|
---|
| 400 | // System.out.println(String.valueOf(i++));
|
---|
| 401 | if (fMarketPreassure)
|
---|
| 402 | if (fNegotiation.getOpponentUtility(this, tmpBid) < 0.3)
|
---|
| 403 | continue;
|
---|
| 404 | if (Math.abs(utilitySpace.getUtility(tmpBid) - pUtility) < ALLOWED_UTILITY_DEVIATION) {
|
---|
| 405 | // double lTmpSim = fSimilarity.getSimilarity(tmpBid,
|
---|
| 406 | // pOppntBid);
|
---|
| 407 | double lTmpExpecteUtility = fNegotiation.getOpponentUtility(
|
---|
| 408 | this, tmpBid); // fOpponentModel.getExpectedUtility(tmpBid);
|
---|
| 409 | if (lTmpExpecteUtility > lExpectedUtility) {
|
---|
| 410 | lExpectedUtility = lTmpExpecteUtility;
|
---|
| 411 | lBid = tmpBid;
|
---|
| 412 | }
|
---|
| 413 | }
|
---|
| 414 | } // while
|
---|
| 415 | return lBid;
|
---|
| 416 | }
|
---|
| 417 |
|
---|
| 418 | protected Bid proposeNextBid(Bid pOppntBid) throws Exception {
|
---|
| 419 | Bid lBid = null;
|
---|
| 420 | switch (fStrategy) {
|
---|
| 421 | case TIT_FOR_TAT:
|
---|
| 422 | lBid = getNextBid(pOppntBid);
|
---|
| 423 | break;
|
---|
| 424 | case SMART:
|
---|
| 425 | lBid = getNextBidSmart(pOppntBid);
|
---|
| 426 | break;
|
---|
| 427 | case AUCTION:
|
---|
| 428 | lBid = getNextBidAuction(pOppntBid);
|
---|
| 429 | break;
|
---|
| 430 | default:
|
---|
| 431 | throw new Exception("unknown strategy " + fStrategy);
|
---|
| 432 | }
|
---|
| 433 | myLastBid = lBid;
|
---|
| 434 | return lBid;
|
---|
| 435 | }
|
---|
| 436 |
|
---|
| 437 | public double getOpponentUtility(Bid bid) throws Exception {
|
---|
| 438 | return fOpponentModel.getExpectedUtility(bid);
|
---|
| 439 | }
|
---|
| 440 |
|
---|
| 441 | public Action chooseAction() {
|
---|
| 442 | Action lAction = null;
|
---|
| 443 | ACTIONTYPE lActionType;
|
---|
| 444 | Bid lOppntBid = null;
|
---|
| 445 |
|
---|
| 446 | try {
|
---|
| 447 | lActionType = getActionType(messageOpponent);
|
---|
| 448 | switch (lActionType) {
|
---|
| 449 | case OFFER: // Offer received from opponent
|
---|
| 450 | lOppntBid = ((Offer) messageOpponent).getBid();
|
---|
| 451 | // if (fOpponentModel.haveSeenBefore(lOppntBid)) {
|
---|
| 452 | // lAction=myLastAction; break; }
|
---|
| 453 | // double lDistance = calculateEuclideanDistanceUtilitySpace();
|
---|
| 454 | // if(myLastAction==null) dumpDistancesToLog(0);
|
---|
| 455 | System.out.print("Updating beliefs ...");
|
---|
| 456 | if (myPreviousBids.size() < 8)
|
---|
| 457 | fOpponentModel.updateBeliefs(lOppntBid);
|
---|
| 458 | // dumpDistancesToLog(fRound++);
|
---|
| 459 | System.out.println("Done!");
|
---|
| 460 | if (myLastAction == null)
|
---|
| 461 | // Other agent started, lets propose my initial bid.
|
---|
| 462 | lAction = proposeInitialBid();
|
---|
| 463 | else {
|
---|
| 464 | double offeredutil = utilitySpace.getUtility(lOppntBid);
|
---|
| 465 | double time = timeline.getTime();
|
---|
| 466 | double P = Paccept(offeredutil, time);
|
---|
| 467 | log("time=" + time + " offeredutil=" + offeredutil
|
---|
| 468 | + " accept probability P=" + P);
|
---|
| 469 | if (utilitySpace.getUtility(lOppntBid) * 1.05 >= utilitySpace
|
---|
| 470 | .getUtility(myLastBid)
|
---|
| 471 | /* || .05*P>Math.random() */) {
|
---|
| 472 | // Opponent bids equally, or outbids my previous bid, so
|
---|
| 473 | // lets accept
|
---|
| 474 | lAction = new Accept(getAgentID(), lOppntBid);
|
---|
| 475 | log("randomly accepted");
|
---|
| 476 | } else {
|
---|
| 477 | Bid lnextBid = proposeNextBid(lOppntBid);
|
---|
| 478 | if (lnextBid == null) {
|
---|
| 479 | lAction = new EndNegotiation(getAgentID());
|
---|
| 480 | } else {
|
---|
| 481 |
|
---|
| 482 | lAction = new Offer(getAgentID(), lnextBid);
|
---|
| 483 |
|
---|
| 484 | // Propose counteroffer. Get next bid.
|
---|
| 485 | // Check if utility of the new bid is lower than
|
---|
| 486 | // utility of the opponent's last bid
|
---|
| 487 | // if yes then accept last bid of the opponent.
|
---|
| 488 | if (utilitySpace.getUtility(lOppntBid) * 1.05 >= utilitySpace
|
---|
| 489 | .getUtility(lnextBid)) {
|
---|
| 490 | // Opponent bids equally, or outbids my previous
|
---|
| 491 | // bid, so lets accept
|
---|
| 492 | lAction = new Accept(getAgentID(), lOppntBid);
|
---|
| 493 | log("opponent's bid higher than util of my last bid! accepted");
|
---|
| 494 | }
|
---|
| 495 | }
|
---|
| 496 |
|
---|
| 497 | }
|
---|
| 498 | // remember current bid of the opponent as its previous bid
|
---|
| 499 | fOpponentPreviousBid = lOppntBid;
|
---|
| 500 | }
|
---|
| 501 | break;
|
---|
| 502 | case ACCEPT:
|
---|
| 503 | case BREAKOFF:
|
---|
| 504 | // nothing left to do. Negotiation ended, which should be
|
---|
| 505 | // checked by
|
---|
| 506 | // Negotiator...
|
---|
| 507 | break;
|
---|
| 508 | default:
|
---|
| 509 | // I am starting, but not sure whether Negotiator checks this,
|
---|
| 510 | // so
|
---|
| 511 | // lets check also myLastAction...
|
---|
| 512 | if (myLastAction == null) {
|
---|
| 513 | // dumpDistancesToLog(fRound++);
|
---|
| 514 | lAction = proposeInitialBid();
|
---|
| 515 | } else
|
---|
| 516 | // simply repeat last action
|
---|
| 517 | lAction = myLastAction;
|
---|
| 518 | break;
|
---|
| 519 | }
|
---|
| 520 | } catch (Exception e) {
|
---|
| 521 | log("Exception in chooseAction:" + e.getMessage());
|
---|
| 522 | e.printStackTrace();
|
---|
| 523 | lAction = new Offer(getAgentID(), myLastBid);
|
---|
| 524 | }
|
---|
| 525 | myLastAction = lAction;
|
---|
| 526 | {
|
---|
| 527 | myPreviousBids.add(((Offer) myLastAction).getBid());
|
---|
| 528 | myLastBid = ((Offer) myLastAction).getBid();
|
---|
| 529 | }
|
---|
| 530 | return lAction;
|
---|
| 531 | }
|
---|
| 532 |
|
---|
| 533 | protected ACTIONTYPE getActionType(Action lAction) {
|
---|
| 534 | ACTIONTYPE lActionType = ACTIONTYPE.START;
|
---|
| 535 | if (lAction instanceof Offer)
|
---|
| 536 | lActionType = ACTIONTYPE.OFFER;
|
---|
| 537 | else if (lAction instanceof Accept)
|
---|
| 538 | lActionType = ACTIONTYPE.ACCEPT;
|
---|
| 539 | else if (lAction instanceof EndNegotiation)
|
---|
| 540 | lActionType = ACTIONTYPE.BREAKOFF;
|
---|
| 541 | return lActionType;
|
---|
| 542 | }
|
---|
| 543 |
|
---|
| 544 | private double getTargetUtility(double myUtility, double oppntUtility) {
|
---|
| 545 | return myUtility - getConcessionFactor();
|
---|
| 546 | }
|
---|
| 547 |
|
---|
| 548 | private double getConcessionFactor() {
|
---|
| 549 | // The more the agent is willing to concess on its aspiration value, the
|
---|
| 550 | // higher this factor.
|
---|
| 551 | return CONCESSIONFACTOR;
|
---|
| 552 | }
|
---|
| 553 |
|
---|
| 554 | /**
|
---|
| 555 | * Prints out debug information only if the fDebug = true
|
---|
| 556 | *
|
---|
| 557 | * @param pMessage
|
---|
| 558 | * - debug informaton to print
|
---|
| 559 | */
|
---|
| 560 | private void log(String pMessage) {
|
---|
| 561 | if (fDebug)
|
---|
| 562 | System.out.println(pMessage);
|
---|
| 563 | }
|
---|
| 564 |
|
---|
| 565 | /**
|
---|
| 566 | * This function determines the accept probability for an offer. At t=0 it
|
---|
| 567 | * will prefer high-utility offers. As t gets closer to 1, it will accept
|
---|
| 568 | * lower utility offers with increasing probability. it will never accept
|
---|
| 569 | * offers with utility 0.
|
---|
| 570 | *
|
---|
| 571 | * @param u
|
---|
| 572 | * is the utility
|
---|
| 573 | * @param t
|
---|
| 574 | * is the time as fraction of the total available time (t=0 at
|
---|
| 575 | * start, and t=1 at end time)
|
---|
| 576 | * @return the probability of an accept at time t
|
---|
| 577 | * @throws Exception
|
---|
| 578 | * if you use wrong values for u or t.
|
---|
| 579 | *
|
---|
| 580 | */
|
---|
| 581 | protected double Paccept(double u, double t1) throws Exception {
|
---|
| 582 | double t = t1 * t1 * t1; // get more relaxed more to the end.
|
---|
| 583 | if (u < 0 || u > 1.05)
|
---|
| 584 | throw new Exception("utility " + u + " outside [0,1]");
|
---|
| 585 | if (t < 0 || t > 1)
|
---|
| 586 | throw new Exception("time " + t + " outside [0,1]");
|
---|
| 587 | if (u > 1.)
|
---|
| 588 | u = 1.;
|
---|
| 589 |
|
---|
| 590 | if (t == 0.5)
|
---|
| 591 | return u;
|
---|
| 592 | return (u - 2. * u * t + 2. * (-1. + t + Math.sqrt(sq(-1. + t) + u
|
---|
| 593 | * (-1. + 2 * t))))
|
---|
| 594 | / (-1. + 2 * t);
|
---|
| 595 | }
|
---|
| 596 |
|
---|
| 597 | private double sq(double x) {
|
---|
| 598 | return x * x;
|
---|
| 599 | }
|
---|
| 600 |
|
---|
| 601 | /*
|
---|
| 602 | * private double calculateEuclideanDistanceUtilitySpace(double[]
|
---|
| 603 | * pLearnedUtil, double[] pOpponentUtil) { double lDistance = 0; try {
|
---|
| 604 | * for(int i=0;i<pLearnedUtil.length;i++) lDistance = lDistance + sq(
|
---|
| 605 | * pOpponentUtil[i]-pLearnedUtil[i]); } catch (Exception e) {
|
---|
| 606 | * e.printStackTrace(); } lDistance = lDistance /
|
---|
| 607 | * utilitySpace.getDomain().getNumberOfPossibleBids(); return lDistance; }
|
---|
| 608 | * private double calculateEuclideanDistanceWeghts(double[] pExpectedWeight)
|
---|
| 609 | * { double lDistance = 0; int i=0; try { for(Issue lIssue :
|
---|
| 610 | * utilitySpace.getDomain().getIssues()) { lDistance = lDistance
|
---|
| 611 | * +sq(fNegotiation.getOpponentWeight(this, lIssue.getNumber())
|
---|
| 612 | * -pExpectedWeight[i]); i++; } } catch (Exception e) { e.printStackTrace();
|
---|
| 613 | * } return lDistance/(double)i; }
|
---|
| 614 | *
|
---|
| 615 | * private double calculatePearsonDistanceUtilitySpace(double[]
|
---|
| 616 | * pLearnedUtility, double[] pOpponentUtil) { double lDistance = 0; double
|
---|
| 617 | * lAverageLearnedUtil=0; double lAverageOriginalUtil=0; //calculate average
|
---|
| 618 | * values for(int i=0;i<pLearnedUtility.length;i++) { lAverageLearnedUtil =
|
---|
| 619 | * lAverageLearnedUtil + pLearnedUtility[i]; lAverageOriginalUtil =
|
---|
| 620 | * lAverageOriginalUtil + pOpponentUtil[i]; } lAverageLearnedUtil =
|
---|
| 621 | * lAverageLearnedUtil
|
---|
| 622 | * /(double)(utilitySpace.getDomain().getNumberOfPossibleBids());
|
---|
| 623 | * lAverageOriginalUtil = lAverageOriginalUtil/
|
---|
| 624 | * (double)(utilitySpace.getDomain().getNumberOfPossibleBids()); //calculate
|
---|
| 625 | * the distance itself double lSumX=0; double lSumY=0; for(int
|
---|
| 626 | * i=0;i<pLearnedUtility.length;i++) { lDistance = lDistance +
|
---|
| 627 | * (pLearnedUtility[i]-lAverageLearnedUtil)*
|
---|
| 628 | * (pOpponentUtil[i]-lAverageOriginalUtil); lSumX = lSumX +
|
---|
| 629 | * sq(pLearnedUtility[i]-lAverageLearnedUtil); lSumY = lSumY +
|
---|
| 630 | * sq(pOpponentUtil[i]-lAverageOriginalUtil);
|
---|
| 631 | *
|
---|
| 632 | * }
|
---|
| 633 | *
|
---|
| 634 | *
|
---|
| 635 | * return lDistance/(Math.sqrt(lSumX*lSumY)); }
|
---|
| 636 | *
|
---|
| 637 | * private double calculatePearsonDistanceWeghts(double[] pExpectedWeight) {
|
---|
| 638 | * double lDistance = 0; double lAverageLearnedWeight=0; double
|
---|
| 639 | * lAverageOriginalWeight=0; int i=0; try { for(Issue lIssue :
|
---|
| 640 | * utilitySpace.getDomain().getIssues()) { lAverageLearnedWeight =
|
---|
| 641 | * lAverageLearnedWeight +pExpectedWeight[i]; lAverageOriginalWeight =
|
---|
| 642 | * lAverageOriginalWeight + fNegotiation.getOpponentWeight(this,
|
---|
| 643 | * lIssue.getNumber()); i++; } } catch (Exception e) { e.printStackTrace();
|
---|
| 644 | * } lAverageLearnedWeight = lAverageLearnedWeight/(double)(i);
|
---|
| 645 | * lAverageOriginalWeight= lAverageOriginalWeight/ (double)(i);
|
---|
| 646 | *
|
---|
| 647 | * //calculate the distance itself i=0; double lSumX=0; double lSumY=0; try
|
---|
| 648 | * { for(Issue lIssue : utilitySpace.getDomain().getIssues()) { lDistance =
|
---|
| 649 | * lDistance +(fNegotiation.getOpponentWeight(this, lIssue.getNumber())-
|
---|
| 650 | * lAverageOriginalWeight)*(pExpectedWeight[i]-lAverageLearnedWeight); lSumX
|
---|
| 651 | * = lSumX + sq(fNegotiation.getOpponentWeight(this, lIssue.getNumber())-
|
---|
| 652 | * lAverageOriginalWeight); lSumY = lSumY +
|
---|
| 653 | * sq(pExpectedWeight[i]-lAverageLearnedWeight); i++; } } catch (Exception
|
---|
| 654 | * e) { e.printStackTrace(); }
|
---|
| 655 | *
|
---|
| 656 | * return lDistance/(Math.sqrt(lSumX*lSumY)); } private double
|
---|
| 657 | * calculateRankingDistanceUtilitySpaceMonteCarlo(double[] pLearnedUtil,
|
---|
| 658 | * double[] pOpponentUtil) { double lDistance = 0; int lNumberOfPossibleBids
|
---|
| 659 | * = (int)(utilitySpace.getDomain().getNumberOfPossibleBids()); int
|
---|
| 660 | * lNumberOfComparisons = 10000000; for(int k=0;k<lNumberOfComparisons ;k++)
|
---|
| 661 | * { int i = (new Random()).nextInt(lNumberOfPossibleBids-1); int j = (new
|
---|
| 662 | * Random()).nextInt(lNumberOfPossibleBids-1);
|
---|
| 663 | * if(((pLearnedUtil[i]>pLearnedUtil
|
---|
| 664 | * [j])&&(pOpponentUtil[i]>pOpponentUtil[j]))||
|
---|
| 665 | * ((pLearnedUtil[i]<pLearnedUtil
|
---|
| 666 | * [j])&&(pOpponentUtil[i]<pOpponentUtil[j]))||
|
---|
| 667 | * ((pLearnedUtil[i]==pLearnedUtil
|
---|
| 668 | * [j])&&(pOpponentUtil[i]==pOpponentUtil[j]))) {
|
---|
| 669 | *
|
---|
| 670 | * } else lDistance++;
|
---|
| 671 | *
|
---|
| 672 | * } return ((double)lDistance)/((double)lNumberOfComparisons); } private
|
---|
| 673 | * double calculateRankingDistanceUtilitySpace(double[] pLearnedUtil,
|
---|
| 674 | * double[] pOpponentUtil) {
|
---|
| 675 | *
|
---|
| 676 | * double lDistance = 0; int lNumberOfPossibleBids =
|
---|
| 677 | * (int)(utilitySpace.getDomain().getNumberOfPossibleBids());
|
---|
| 678 | *
|
---|
| 679 | * try { for(int i=0;i<lNumberOfPossibleBids-1;i++) { for(int
|
---|
| 680 | * j=i+1;j<lNumberOfPossibleBids;j++) { //if(i==j) continue; if
|
---|
| 681 | * (Math.signum(
|
---|
| 682 | * pLearnedUtil[i]-pLearnedUtil[j])!=Math.signum(pOpponentUtil[i
|
---|
| 683 | * ]-pOpponentUtil[j])) lDistance++;
|
---|
| 684 | *
|
---|
| 685 | * } //for } //for } catch (Exception e) { e.printStackTrace(); }
|
---|
| 686 | *
|
---|
| 687 | * lDistance = 2 * lDistance /
|
---|
| 688 | * (utilitySpace.getDomain().getNumberOfPossibleBids
|
---|
| 689 | * ()*(utilitySpace.getDomain().getNumberOfPossibleBids())); return
|
---|
| 690 | * lDistance; } private double calculateRankingDistanceWeghts(double
|
---|
| 691 | * pExpectedWeights[]) { double lDistance = 0; double[] lOriginalWeights =
|
---|
| 692 | * new double[utilitySpace.getDomain().getIssues().size()]; int k=0; try {
|
---|
| 693 | * for(Issue lIssue : utilitySpace.getDomain().getIssues()) {
|
---|
| 694 | * lOriginalWeights[k] = fNegotiation.getOpponentWeight(this,
|
---|
| 695 | * lIssue.getNumber()); k++; } } catch (Exception e) { e.printStackTrace();
|
---|
| 696 | * } k=0; int nrOfIssues = utilitySpace.getDomain().getIssues().size();
|
---|
| 697 | * for(int i=0; i<nrOfIssues-1;i++) { for(int j=i+1;j<nrOfIssues;j++) { k++;
|
---|
| 698 | * double tmpWeightLearned = pExpectedWeights[i]; double tmpWeightOriginal =
|
---|
| 699 | * lOriginalWeights[i]; double tmpWeight2Learned = pExpectedWeights[j];
|
---|
| 700 | * double tmpWeight2Original = lOriginalWeights[j];
|
---|
| 701 | * if(((tmpWeightLearned>tmpWeight2Learned
|
---|
| 702 | * )&&(tmpWeightOriginal>tmpWeight2Original))||
|
---|
| 703 | * ((tmpWeightLearned<tmpWeight2Learned
|
---|
| 704 | * )&&(tmpWeightOriginal<tmpWeight2Original))||
|
---|
| 705 | * ((tmpWeightLearned==tmpWeight2Learned
|
---|
| 706 | * )&&(tmpWeightOriginal==tmpWeight2Original))) {
|
---|
| 707 | *
|
---|
| 708 | * } else lDistance++;
|
---|
| 709 | *
|
---|
| 710 | * } } return ((double)lDistance)/((double)k); }
|
---|
| 711 | *
|
---|
| 712 | * protected void dumpDistancesToLog(int pRound) { if (fSkipDistanceCalc)
|
---|
| 713 | * return; System.out.print(getName() +
|
---|
| 714 | * ": calculating distance between the learned space and the original one ..."
|
---|
| 715 | * );
|
---|
| 716 | *
|
---|
| 717 | * double lExpectedWeights[] = new
|
---|
| 718 | * double[utilitySpace.getDomain().getIssues().size()]; int i=0; for(Issue
|
---|
| 719 | * lIssue : utilitySpace.getDomain().getIssues()) {
|
---|
| 720 | * lExpectedWeights[i]=fOpponentModel.getExpectedWeight(i); i++; }
|
---|
| 721 | *
|
---|
| 722 | *
|
---|
| 723 | * double pLearnedUtil[] = new
|
---|
| 724 | * double[(int)(utilitySpace.getDomain().getNumberOfPossibleBids())]; //
|
---|
| 725 | * HashMap<Bid, Double> pLearnedSpace = new HashMap<Bid, Double>();
|
---|
| 726 | * BidIterator lIter = new BidIterator( utilitySpace.getDomain()); i=0;
|
---|
| 727 | * while(lIter.hasNext()) { Bid lBid = lIter.next(); try { pLearnedUtil[i]
|
---|
| 728 | * =fOpponentModel.getNormalizedUtility(lBid); // pLearnedSpace.put(lBid,
|
---|
| 729 | * new Double(pLearnedUtil[i]));
|
---|
| 730 | *
|
---|
| 731 | * } catch (Exception e) { e.printStackTrace(); } i++; } double
|
---|
| 732 | * pOpponentUtil[] = new
|
---|
| 733 | * double[(int)(utilitySpace.getDomain().getNumberOfPossibleBids())]; //
|
---|
| 734 | * HashMap<Bid, Double> pOpponentSpace = new HashMap<Bid, Double>(); lIter =
|
---|
| 735 | * new BidIterator( utilitySpace.getDomain()); i=0; while(lIter.hasNext()) {
|
---|
| 736 | * Bid lBid = lIter.next(); try { pOpponentUtil[i] =
|
---|
| 737 | * fNegotiation.getOpponentUtility(this, lBid); // pOpponentSpace.put(lBid,
|
---|
| 738 | * new Double(pOpponentUtil[i])); } catch (Exception e) {
|
---|
| 739 | * e.printStackTrace(); } i++; }
|
---|
| 740 | *
|
---|
| 741 | * double lEuclideanDistUtil =
|
---|
| 742 | * calculateEuclideanDistanceUtilitySpace(pLearnedUtil,pOpponentUtil);
|
---|
| 743 | * double lEuclideanDistWeights =
|
---|
| 744 | * calculateEuclideanDistanceWeghts(lExpectedWeights); double
|
---|
| 745 | * lRankingDistUtil = 0;
|
---|
| 746 | * if((int)(utilitySpace.getDomain().getNumberOfPossibleBids())>100000)
|
---|
| 747 | * lRankingDistUtil =
|
---|
| 748 | * calculateRankingDistanceUtilitySpaceMonteCarlo(pLearnedUtil,
|
---|
| 749 | * pOpponentUtil); else lRankingDistUtil =
|
---|
| 750 | * calculateRankingDistanceUtilitySpace(pLearnedUtil, pOpponentUtil); double
|
---|
| 751 | * lRankingDistWeights = calculateRankingDistanceWeghts(lExpectedWeights);
|
---|
| 752 | * double lPearsonDistUtil =
|
---|
| 753 | * calculatePearsonDistanceUtilitySpace(pLearnedUtil,pOpponentUtil); double
|
---|
| 754 | * lPearsonDistWeights = calculatePearsonDistanceWeghts(lExpectedWeights);
|
---|
| 755 | * SimpleElement lLearningPerformance = new
|
---|
| 756 | * SimpleElement("learning_performance");
|
---|
| 757 | * lLearningPerformance.setAttribute("round", String.valueOf(pRound));
|
---|
| 758 | * lLearningPerformance.setAttribute("euclidean_distance_utility_space",
|
---|
| 759 | * String.valueOf(lEuclideanDistUtil));
|
---|
| 760 | * lLearningPerformance.setAttribute("euclidean_distance_weights",
|
---|
| 761 | * String.valueOf(lEuclideanDistWeights));
|
---|
| 762 | * lLearningPerformance.setAttribute("ranking_distance_utility_space",
|
---|
| 763 | * String.valueOf(lRankingDistUtil));
|
---|
| 764 | * lLearningPerformance.setAttribute("ranking_distance_weights",
|
---|
| 765 | * String.valueOf(lRankingDistWeights));
|
---|
| 766 | * lLearningPerformance.setAttribute("pearson_distance_utility_space",
|
---|
| 767 | * String.valueOf(lPearsonDistUtil));
|
---|
| 768 | * lLearningPerformance.setAttribute("pearson_distance_weights",
|
---|
| 769 | * String.valueOf(lPearsonDistWeights)); System.out.println("Done!");
|
---|
| 770 | * System.out.println(lLearningPerformance.toString());
|
---|
| 771 | * fNegotiation.addAdditionalLog(lLearningPerformance);
|
---|
| 772 | *
|
---|
| 773 | * }
|
---|
| 774 | */
|
---|
| 775 | public final Bid getMaxUtilityBid() throws Exception {
|
---|
| 776 | Bid maxBid = null;
|
---|
| 777 | double maxutil = 0.;
|
---|
| 778 | BidIterator bidit = new BidIterator(utilitySpace.getDomain());
|
---|
| 779 |
|
---|
| 780 | if (bidit.hasNext())
|
---|
| 781 | maxBid = bidit.next();
|
---|
| 782 | else
|
---|
| 783 | throw new Exception("The domain does not contain any bids!");
|
---|
| 784 | while (bidit.hasNext()) {
|
---|
| 785 | Bid thisBid = bidit.next();
|
---|
| 786 | if (fMarketPreassure)
|
---|
| 787 | if (fNegotiation.getOpponentUtility(this, thisBid) < 0.3)
|
---|
| 788 | continue;
|
---|
| 789 | double thisutil = utilitySpace.getUtility(thisBid);
|
---|
| 790 | if (thisutil > maxutil) {
|
---|
| 791 | maxutil = thisutil;
|
---|
| 792 | maxBid = thisBid;
|
---|
| 793 | }
|
---|
| 794 | }
|
---|
| 795 | return maxBid;
|
---|
| 796 | }
|
---|
| 797 |
|
---|
| 798 | }
|
---|