@Override
/** Bid the minimum amount possible. */
public int bidAmount(Auction auction) {
int amount = auction.minimumBid();
if (r.nextDouble() > 0.98) {
int change =
Math.max(
0, (int) ((1 - auction.proportionOfTrueValuation()) * 0.1 * auction.trueValue()));
amount += change;
}
return amount;
}
@Override
public boolean shouldBid(Auction shillAuction, long currentTime) {
if (shillAuction
.hasNoBids()) { // wait if no one else has bid yet, don't bid until 70% of auction has
// elapsed
return false;
}
boolean d3success = directive3(theta, shillAuction, currentTime);
boolean d4success = directive4(alpha, shillAuction);
boolean d5success = directive5(mu, theta, currentTime, shillAuction);
return d3success && d4success && d5success;
}
/**
* D5 of Simple Shilling Agent by Trevathan; bid when bid volume is high
*
* @param mu
* @param auction
* @return true if should bid, else false
*/
private static boolean directive5(double mu, double theta, long currentTime, Auction auction) {
if (auction.getBidCount() == 0) return true;
double muTime =
proportionToTime(
1 - mu,
auction.getStartTime(),
currentTime); // D5, how far back to look when counting bids
double thetaTime =
proportionToTime(
theta, auction.getStartTime(), auction.getEndTime()); // D3, don't bid too close to end
int numberOfBids = numberOfBids(auction.getBidHistory(), (long) (muTime + 0.5));
// System.out.println("numberOfBids: " + numberOfBids);
if (numberOfBids > 1) {
return true;
} else if (numberOfBids == 1) {
// find the proportion of time time left available for the shill bidder to act
double normalisedTime = proportionRemaining(auction.getStartTime(), thetaTime, currentTime);
// System.out.println("normalisedTime: " + normalisedTime);
if (normalisedTime < 0.85) return true;
}
return false;
}
/** D4 of Simple Shilling Agent by Trevathan; bid until target price is reached */
private static boolean directive4(double alpha, Auction auction) {
double proportionPrice = auction.getCurrentPrice() / auction.trueValue();
// System.out.println("proportionPrice: " + proportionPrice);
return alpha > proportionPrice;
}
/** D3 of Simple Shilling Agent by Trevathan; don't bid too close to auction end */
private static boolean directive3(double theta, Auction auction, long time) {
double proportionRemaining =
proportionRemaining(auction.getStartTime(), auction.getEndTime(), time);
// System.out.println("proportionRemaining: " + proportionRemaining);
return proportionRemaining <= theta;
}