[32] | 1 | package geniusweb.bidspace.pareto;
|
---|
| 2 |
|
---|
| 3 | import java.math.BigDecimal;
|
---|
| 4 | import java.util.ArrayList;
|
---|
| 5 | import java.util.HashMap;
|
---|
| 6 | import java.util.LinkedList;
|
---|
| 7 | import java.util.List;
|
---|
| 8 | import java.util.Map;
|
---|
| 9 |
|
---|
| 10 | import geniusweb.issuevalue.Bid;
|
---|
| 11 | import geniusweb.issuevalue.Value;
|
---|
| 12 | import geniusweb.profile.utilityspace.LinearAdditive;
|
---|
| 13 |
|
---|
| 14 | /**
|
---|
| 15 | * A Paretopoint is a Bid together with an N-dimensional utility vector. This is
|
---|
| 16 | * also a caching mechanism to avoid repeated utility computation of good bids.
|
---|
| 17 | * This is a internal utility class to streamline pareto computations.
|
---|
| 18 | */
|
---|
| 19 | class ParetoPoint {
|
---|
| 20 |
|
---|
| 21 | private final Bid bid;
|
---|
| 22 | // ArrayList is faster in indexing which is main reason for this class
|
---|
| 23 | private final ArrayList<BigDecimal> utilities;
|
---|
| 24 |
|
---|
| 25 | /**
|
---|
| 26 | *
|
---|
| 27 | * @param bid a (possibly partial) {@link Bid}
|
---|
| 28 | * @param spaces the {@link LinearAdditive}s to consider
|
---|
| 29 | */
|
---|
| 30 | public ParetoPoint(Bid bid, List<LinearAdditive> spaces) {
|
---|
| 31 | this.bid = bid;
|
---|
| 32 | utilities = new ArrayList<>();
|
---|
| 33 | for (LinearAdditive space : spaces) {
|
---|
| 34 | utilities.add(space.getUtility(bid));
|
---|
| 35 | }
|
---|
| 36 | }
|
---|
| 37 |
|
---|
| 38 | private ParetoPoint(List<BigDecimal> utils, Bid bid) {
|
---|
| 39 | this.bid = bid;
|
---|
| 40 | this.utilities = new ArrayList<>(utils);
|
---|
| 41 | }
|
---|
| 42 |
|
---|
| 43 | /**
|
---|
| 44 | * Merges the issues from both bids and adds the utilities. This only works
|
---|
| 45 | * correctly if the issues in other point are completely disjoint from our
|
---|
| 46 | * bid issues.
|
---|
| 47 | *
|
---|
| 48 | * @param otherpoint with the utils summed and the issue values merged
|
---|
| 49 | */
|
---|
| 50 | public ParetoPoint merge(ParetoPoint otherpoint) {
|
---|
| 51 | Map<String, Value> issuevalues = new HashMap<>();
|
---|
| 52 | for (String issue : bid.getIssues()) {
|
---|
| 53 | issuevalues.put(issue, bid.getValue(issue));
|
---|
| 54 | }
|
---|
| 55 | for (String issue : otherpoint.bid.getIssues()) {
|
---|
| 56 | issuevalues.put(issue, otherpoint.bid.getValue(issue));
|
---|
| 57 | }
|
---|
| 58 | List<BigDecimal> summedutils = new LinkedList<>();
|
---|
| 59 | for (int n = 0; n < utilities.size(); n++) {
|
---|
| 60 | summedutils.add(utilities.get(n).add(otherpoint.utilities.get(n)));
|
---|
| 61 | }
|
---|
| 62 |
|
---|
| 63 | return new ParetoPoint(summedutils, new Bid(issuevalues));
|
---|
| 64 | }
|
---|
| 65 |
|
---|
| 66 | /**
|
---|
| 67 | *
|
---|
| 68 | * @param other
|
---|
| 69 | * @return true if this ParetoPoint is dominated by the other. That means
|
---|
| 70 | * other has better or equal utilities in ALL dimensions.
|
---|
| 71 | */
|
---|
| 72 | public boolean isDominatedBy(ParetoPoint other) {
|
---|
| 73 | ArrayList<BigDecimal> otherutils = other.getUtilities();
|
---|
| 74 | for (int i = 0; i < utilities.size(); i++) {
|
---|
| 75 | if (otherutils.get(i).compareTo(utilities.get(i)) < 0) {
|
---|
| 76 | return false;
|
---|
| 77 | }
|
---|
| 78 | }
|
---|
| 79 | return true;
|
---|
| 80 | }
|
---|
| 81 |
|
---|
| 82 | protected ArrayList<BigDecimal> getUtilities() {
|
---|
| 83 | return utilities;
|
---|
| 84 | }
|
---|
| 85 |
|
---|
| 86 | public Bid getBid() {
|
---|
| 87 | return bid;
|
---|
| 88 | }
|
---|
| 89 |
|
---|
| 90 | } |
---|