source: src/main/java/agents/anac/y2010/Southampton/utils/concession/ConcessionUtils.java

Last change on this file was 1, checked in by Wouter Pasman, 6 years ago

Initial import : Genius 9.0.0
File size: 4.8 KB
Line 
1package agents.anac.y2010.Southampton.utils.concession;
2
3import java.util.ArrayList;
4import agents.anac.y2010.Southampton.utils.Pair;
5
6public class ConcessionUtils {
7
8 public static double getBeta(ArrayList<Pair<Double, Double>> bestOpponentBidUtilityHistory, double time, double discounting, double utility0,
9 double utility1) {
10 return getBeta(bestOpponentBidUtilityHistory, time, discounting, utility0, utility1, 0.1, 0.01, 2, 1, 1, 1);
11 }
12
13 public static double getBeta(ArrayList<Pair<Double, Double>> bestOpponentBidUtilityHistory, double time, double discounting, double utility0,
14 double utility1, double minDiscounting, double minBeta, double maxBeta, double defaultBeta, double ourTime, double opponentTime) {
15 discounting = Math.max(discounting, minDiscounting);
16 try {
17 // Estimate the alpha value.
18 //double alpha = getAlpha(bestOpponentBidUtilityHistory);
19 Pair<Double, Double> params = getRegressionParameters(bestOpponentBidUtilityHistory, utility0);
20 double a = params.fst;
21 double b = params.snd;
22 // Find the maxima.
23 double maxima = getMaxima(a, b, time, discounting, utility0, opponentTime);
24 // Find the current utility of our current concession strategy.
25 //double util = utility0 + (utility1 - utility0) * (1 - Math.exp(-alpha * maxima));
26 double util = utility0 + (Math.exp(a) * Math.pow(maxima, b));
27 util = Math.max(0, Math.min(1, util));
28 // Calculate the beta value.
29 double beta = Math.max(0, Math.log(maxima) / Math.log((1 - util) / 0.5));
30 /*
31 if (time < 0.5) {
32 double weightBeta = time / 0.5;
33 //beta = (beta * weightBeta) + (defaultBeta * (1 - weightBeta));
34 beta = Math.exp(Math.log(beta) * weightBeta) + Math.exp(Math.log(defaultBeta) * (1 - weightBeta));
35 }
36 */
37
38 return Math.min(maxBeta, Math.max(minBeta, beta));
39 } catch (Exception ex) {
40 return defaultBeta;
41 }
42 }
43
44 private static Pair<Double, Double> getRegressionParameters(ArrayList<Pair<Double, Double>> bestOpponentBidUtilityHistory, double utility0) {
45 double n = 1;
46 double x = 0;//Math.log(1);
47 double y = Math.log(1 - utility0);
48 double sumlnxlny = 0;//x * y;
49 double sumlnx = 0;//x;
50 double sumlny = y;
51 double sumlnxlnx = 0;//x * y;
52 for (Pair<Double, Double> d : bestOpponentBidUtilityHistory) {
53 x = Math.log(d.snd);
54 y = Math.log(d.fst - utility0);
55
56 if(Double.isNaN(x))
57 throw new RuntimeException("Unable to perform regression using provided points (x).");
58 if(Double.isNaN(y))
59 throw new RuntimeException("Unable to perform regression using provided points (y).");
60 if(Double.isInfinite(x) || Double.isInfinite(y))
61 continue;
62
63 sumlnxlny += x * y;
64 sumlnx += x;
65 sumlny += y;
66 sumlnxlnx += x * x;
67 n++;
68 }
69
70 double b = ((n * sumlnxlny) - (sumlnx * sumlny)) / ((n * sumlnxlnx) - (sumlnx * sumlnx));
71 if(Double.isNaN(b))
72 throw new RuntimeException("Unable to perform regression using provided points (b)." + (sumlnxlny) + ", " + (n * sumlnxlnx) + ", " + (sumlnx * sumlnx));
73 double a = (sumlny - (b * sumlnx)) / n;
74
75 if(Double.isNaN(a))
76 throw new RuntimeException("Unable to perform regression using provided points (a).");
77 return new Pair<Double, Double>(a, b);
78 }
79
80 /*
81 private static double getMaxima(double alpha, double time, double discounting, double utility0, double utility1) {
82 double alpharoot = Math.log((discounting * utility1) / ((alpha + discounting) * (utility1 - utility0))) / -alpha;
83 ArrayList<Double> maxima = new ArrayList<Double>();
84 if (alpharoot >= 0 && alpharoot <= 1 && alpharoot > time) {
85 maxima.add(alpharoot);
86 }
87 maxima.add(time);
88 maxima.add(1.0);
89 double maxUtil = 0;
90 double result = 0;
91 for (double maximum : maxima) {
92 double util = (utility0 + ((utility1 - utility0) * (1 - Math.exp(-alpha * maximum)))) * Math.exp(-discounting * maximum);
93 if (util > maxUtil) {
94 result = maximum;
95 maxUtil = util;
96 }
97 }
98 return result;
99 }
100 */
101
102 private static double getMaxima(double a, double b, double time, double discounting, double utility0, double opponentTime) {
103 //double root = b / discounting;
104 ArrayList<Double> maxima = new ArrayList<Double>();
105 maxima.add(time);
106 for(int i=(int) Math.floor(time*1000); i<=1000; i++) {
107 double root = (double)i / 1000.0;
108 //if (root >= 0 && root <= 1 && root > time) {
109 maxima.add(root);
110 //}
111 }
112 maxima.add(1.0);
113 double maxUtil = 0;
114 double result = 0;
115
116 double timeScaledDiscounting = -discounting * getTimeScaleFactor(time, opponentTime);
117 double expA = Math.exp(a);
118
119 for (double maximum : maxima) {
120 double util = (utility0 + (expA * Math.pow(maximum, b))) * Math.exp(timeScaledDiscounting * maximum);
121 if (util > maxUtil) {
122 result = maximum;
123 maxUtil = util;
124 }
125 }
126 return result;
127 }
128
129 private static double getTimeScaleFactor(double ourTime, double opponentTime) {
130 double sf = (ourTime + opponentTime)/(ourTime * 2.0);
131 return sf;
132 }
133
134}
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