1 | #region License Information
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2 | /* HeuristicLab
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3 | * Copyright (C) 2002-2010 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
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4 | *
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5 | * This file is part of HeuristicLab.
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6 | *
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7 | * HeuristicLab is free software: you can redistribute it and/or modify
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8 | * it under the terms of the GNU General Public License as published by
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9 | * the Free Software Foundation, either version 3 of the License, or
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10 | * (at your option) any later version.
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11 | *
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12 | * HeuristicLab is distributed in the hope that it will be useful,
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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15 | * GNU General Public License for more details.
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16 | *
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17 | * You should have received a copy of the GNU General Public License
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18 | * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
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19 | */
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20 | #endregion
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21 |
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22 | using System;
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23 | using System.Collections.Generic;
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24 | using HeuristicLab.Core;
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25 | using HeuristicLab.Data;
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26 | using HeuristicLab.Encodings.PermutationEncoding;
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27 | using HeuristicLab.Optimization;
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28 | using HeuristicLab.Parameters;
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29 | using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
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30 |
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31 | namespace HeuristicLab.Problems.VehicleRouting {
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32 | [StorableClass]
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33 | public abstract class PushForwardCreator : IntListRepresentationCreator, IStochasticOperator {
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34 | #region IStochasticOperator Members
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35 | public ILookupParameter<IRandom> RandomParameter {
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36 | get { return (LookupParameter<IRandom>)Parameters["Random"]; }
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37 | }
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38 | #endregion
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39 |
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40 | public IValueParameter<DoubleValue> Alpha {
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41 | get { return (IValueParameter<DoubleValue>)Parameters["Alpha"]; }
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42 | }
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43 | public IValueParameter<DoubleValue> AlphaVariance {
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44 | get { return (IValueParameter<DoubleValue>)Parameters["AlphaVariance"]; }
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45 | }
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46 | public IValueParameter<DoubleValue> Beta {
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47 | get { return (IValueParameter<DoubleValue>)Parameters["Beta"]; }
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48 | }
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49 | public IValueParameter<DoubleValue> BetaVariance {
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50 | get { return (IValueParameter<DoubleValue>)Parameters["BetaVariance"]; }
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51 | }
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52 | public IValueParameter<DoubleValue> Gamma {
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53 | get { return (IValueParameter<DoubleValue>)Parameters["Gamma"]; }
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54 | }
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55 | public IValueParameter<DoubleValue> GammaVariance {
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56 | get { return (IValueParameter<DoubleValue>)Parameters["GammaVariance"]; }
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57 | }
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58 |
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59 | public PushForwardCreator()
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60 | : base() {
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61 | Parameters.Add(new LookupParameter<IRandom>("Random", "The pseudo random number generator."));
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62 | Parameters.Add(new ValueParameter<DoubleValue>("Alpha", "The alpha value.", new DoubleValue(0.7)));
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63 | Parameters.Add(new ValueParameter<DoubleValue>("AlphaVariance", "The alpha variance.", new DoubleValue(0.5)));
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64 | Parameters.Add(new ValueParameter<DoubleValue>("Beta", "The beta value.", new DoubleValue(0.1)));
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65 | Parameters.Add(new ValueParameter<DoubleValue>("BetaVariance", "The beta variance.", new DoubleValue(0.07)));
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66 | Parameters.Add(new ValueParameter<DoubleValue>("Gamma", "The gamma value.", new DoubleValue(0.2)));
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67 | Parameters.Add(new ValueParameter<DoubleValue>("GammaVariance", "The gamma variance.", new DoubleValue(0.14)));
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68 | }
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69 |
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70 | // use the Box-Mueller transform in the polar form to generate a N(0,1) random variable out of two uniformly distributed random variables
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71 | private double Gauss(IRandom random) {
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72 | double u = 0.0, v = 0.0, s = 0.0;
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73 | do {
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74 | u = (random.NextDouble() * 2) - 1;
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75 | v = (random.NextDouble() * 2) - 1;
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76 | s = Math.Sqrt(u * u + v * v);
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77 | } while (s < Double.Epsilon || s > 1);
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78 | return u * Math.Sqrt((-2.0 * Math.Log(s)) / s);
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79 | }
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80 |
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81 | private double N(double mu, double sigma, IRandom random) {
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82 | return mu + (sigma * Gauss(random)); // transform the random variable sampled from N(0,1) to N(mu,sigma)
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83 | }
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84 |
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85 | private double CalculateDistance(int start, int end) {
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86 | double distance = 0.0;
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87 | DoubleMatrix coordinates = CoordinatesParameter.ActualValue;
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88 |
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89 | distance =
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90 | Math.Sqrt(
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91 | Math.Pow(coordinates[start, 0] - coordinates[end, 0], 2) +
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92 | Math.Pow(coordinates[start, 1] - coordinates[end, 1], 2));
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93 |
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94 | return distance;
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95 | }
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96 |
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97 | private DoubleMatrix CreateDistanceMatrix() {
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98 | DoubleMatrix coordinates = CoordinatesParameter.ActualValue;
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99 | DoubleMatrix distanceMatrix = new DoubleMatrix(coordinates.Rows, coordinates.Rows);
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100 |
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101 | for (int i = 0; i < distanceMatrix.Rows; i++) {
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102 | for (int j = i; j < distanceMatrix.Columns; j++) {
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103 | double distance = CalculateDistance(i, j);
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104 |
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105 | distanceMatrix[i, j] = distance;
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106 | distanceMatrix[j, i] = distance;
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107 | }
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108 | }
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109 |
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110 | return distanceMatrix;
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111 | }
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112 |
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113 | private double Distance(int start, int end) {
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114 | double distance = 0.0;
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115 |
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116 | if (UseDistanceMatrixParameter.ActualValue.Value) {
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117 | if (DistanceMatrixParameter.ActualValue == null) {
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118 | DistanceMatrixParameter.ActualValue = CreateDistanceMatrix();
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119 | }
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120 |
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121 | distance = DistanceMatrixParameter.ActualValue[start, end];
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122 | } else {
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123 | distance = CalculateDistance(start, end);
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124 | }
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125 |
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126 | return distance;
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127 | }
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128 |
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129 | private double TravelDistance(List<int> route, int begin) {
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130 | double distance = 0;
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131 | for (int i = begin; i < route.Count - 1 && (i == begin || route[i] != 0); i++) {
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132 | distance += Distance(route[i], route[i + 1]);
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133 | }
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134 | return distance;
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135 | }
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136 |
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137 | private bool SubrouteConstraintsOK(List<int> route, int begin) {
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138 | double t = 0.0, o = 0.0;
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139 | for (int i = begin + 1; i < route.Count; i++) {
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140 | t += Distance(route[i - 1], route[i]);
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141 | if (route[i] == 0) return (t < DueTimeParameter.ActualValue[0]); // violation on capacity constraint is handled below
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142 | else {
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143 | if (t > DueTimeParameter.ActualValue[route[i]]) return false;
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144 | t = Math.Max(ReadyTimeParameter.ActualValue[route[i]], t);
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145 | t += ServiceTimeParameter.ActualValue[route[i]];
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146 | o += DemandParameter.ActualValue[route[i]];
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147 | if (o > CapacityParameter.ActualValue.Value) return false; // premature exit on capacity constraint violation
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148 | }
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149 | }
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150 | return true;
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151 | }
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152 |
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153 | private bool SubrouteTardinessOK(List<int> route, int begin) {
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154 | double t = 0.0;
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155 | for (int i = begin + 1; i < route.Count; i++) {
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156 | t += Distance(route[i - 1], route[i]);
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157 | if (route[i] == 0) {
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158 | if (t < DueTimeParameter.ActualValue[0]) return true;
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159 | else return false;
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160 | } else {
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161 | if (t > DueTimeParameter.ActualValue[route[i]]) return false;
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162 | t = Math.Max(ReadyTimeParameter.ActualValue[route[i]], t);
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163 | t += ServiceTimeParameter.ActualValue[route[i]];
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164 | }
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165 | }
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166 | return true;
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167 | }
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168 |
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169 | private bool SubrouteLoadOK(List<int> route, int begin) {
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170 | double o = 0.0;
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171 | for (int i = begin + 1; i < route.Count; i++) {
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172 | if (route[i] == 0) return (o < CapacityParameter.ActualValue.Value);
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173 | else {
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174 | o += DemandParameter.ActualValue[route[i]];
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175 | }
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176 | }
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177 | return (o < CapacityParameter.ActualValue.Value);
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178 | }
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179 |
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180 | protected override List<int> CreateSolution() {
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181 | double alpha, beta, gamma;
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182 | alpha = N(Alpha.Value.Value, Math.Sqrt(AlphaVariance.Value.Value), RandomParameter.ActualValue);
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183 | beta = N(Beta.Value.Value, Math.Sqrt(BetaVariance.Value.Value), RandomParameter.ActualValue);
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184 | gamma = N(Gamma.Value.Value, Math.Sqrt(GammaVariance.Value.Value), RandomParameter.ActualValue);
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185 |
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186 | double x0 = CoordinatesParameter.ActualValue[0, 0];
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187 | double y0 = CoordinatesParameter.ActualValue[0, 1];
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188 | double distance = 0;
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189 | double cost = 0;
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190 | double minimumCost = double.MaxValue;
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191 | List<int> unroutedList = new List<int>();
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192 | List<double> costList = new List<double>();
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193 | int index;
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194 | int indexOfMinimumCost = -1;
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195 | int indexOfCustomer = -1;
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196 |
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197 | /*-----------------------------------------------------------------------------
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198 | * generate cost list
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199 | *-----------------------------------------------------------------------------
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200 | */
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201 | for (int i = 1; i <= CitiesParameter.ActualValue.Value; i++) {
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202 | distance = Distance(i, 0);
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203 | if (CoordinatesParameter.ActualValue[i, 0] < x0) distance = -distance;
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204 | cost = -alpha * distance + // distance 0 <-> City[i]
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205 | beta * (DueTimeParameter.ActualValue[i]) + // latest arrival time
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206 | gamma * (Math.Asin((CoordinatesParameter.ActualValue[i, 1] - y0) / distance) / 360 * distance); // polar angle
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207 |
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208 | index = 0;
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209 | while (index < costList.Count && costList[index] < cost) index++;
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210 | costList.Insert(index, cost);
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211 | unroutedList.Insert(index, i);
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212 | }
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213 |
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214 | /*------------------------------------------------------------------------------
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215 | * route customers according to cost list
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216 | *------------------------------------------------------------------------------
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217 | */
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218 | int routeIndex = 0;
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219 | int currentRoute = 0;
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220 | int c;
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221 | int customer = -1;
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222 | int subTourCount = 1;
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223 | List<int> route = new List<int>(CitiesParameter.ActualValue.Value + VehiclesParameter.ActualValue.Value - 1);
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224 | minimumCost = double.MaxValue;
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225 | indexOfMinimumCost = -1;
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226 | route.Add(0);
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227 | route.Add(0);
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228 | route.Insert(1, unroutedList[0]);
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229 | unroutedList.RemoveAt(0);
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230 | currentRoute = routeIndex;
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231 | routeIndex++;
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232 |
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233 | do {
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234 | for (c = 0; c < unroutedList.Count; c++) {
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235 | for (int i = currentRoute + 1; i < route.Count; i++) {
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236 | route.Insert(i, (int)unroutedList[c]);
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237 | if (route[currentRoute] != 0) { throw new Exception("currentRoute not depot"); }
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238 | cost = TravelDistance(route, currentRoute);
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239 | if (cost < minimumCost && SubrouteConstraintsOK(route, currentRoute)) {
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240 | minimumCost = cost;
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241 | indexOfMinimumCost = i;
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242 | customer = (int)unroutedList[c];
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243 | indexOfCustomer = c;
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244 | }
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245 | route.RemoveAt(i);
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246 | }
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247 | }
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248 | // insert customer if found
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249 | if (indexOfMinimumCost != -1) {
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250 | route.Insert(indexOfMinimumCost, customer);
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251 | routeIndex++;
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252 | unroutedList.RemoveAt(indexOfCustomer);
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253 | costList.RemoveAt(indexOfCustomer);
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254 | } else { // no feasible customer found
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255 | routeIndex++;
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256 | route.Insert(routeIndex, 0);
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257 | currentRoute = routeIndex;
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258 | route.Insert(route.Count - 1, (int)unroutedList[0]);
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259 | unroutedList.RemoveAt(0);
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260 | routeIndex++;
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261 | subTourCount++;
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262 | }
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263 | // reset minimum
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264 | minimumCost = double.MaxValue;
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265 | indexOfMinimumCost = -1;
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266 | indexOfCustomer = -1;
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267 | customer = -1;
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268 | } while (unroutedList.Count > 0);
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269 | while (route.Count < CitiesParameter.ActualValue.Value + VehiclesParameter.ActualValue.Value - 1)
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270 | route.Add(0);
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271 |
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272 | return route;
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273 | }
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274 | }
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275 | }
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