1 | #region License Information
|
---|
2 | /* HeuristicLab
|
---|
3 | * Copyright (C) 2002-2010 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
|
---|
4 | *
|
---|
5 | * This file is part of HeuristicLab.
|
---|
6 | *
|
---|
7 | * HeuristicLab is free software: you can redistribute it and/or modify
|
---|
8 | * it under the terms of the GNU General Public License as published by
|
---|
9 | * the Free Software Foundation, either version 3 of the License, or
|
---|
10 | * (at your option) any later version.
|
---|
11 | *
|
---|
12 | * HeuristicLab is distributed in the hope that it will be useful,
|
---|
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
---|
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
---|
15 | * GNU General Public License for more details.
|
---|
16 | *
|
---|
17 | * You should have received a copy of the GNU General Public License
|
---|
18 | * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
|
---|
19 | */
|
---|
20 | #endregion
|
---|
21 |
|
---|
22 | using System;
|
---|
23 | using System.Collections.Generic;
|
---|
24 | using System.Linq;
|
---|
25 | using System.Text;
|
---|
26 | using HeuristicLab.Operators;
|
---|
27 | using HeuristicLab.Core;
|
---|
28 | using HeuristicLab.Data;
|
---|
29 | using HeuristicLab.Parameters;
|
---|
30 | using HeuristicLab.Encodings.PermutationEncoding;
|
---|
31 | using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
|
---|
32 | using HeuristicLab.Common;
|
---|
33 | using HeuristicLab.Optimization;
|
---|
34 |
|
---|
35 | namespace HeuristicLab.Problems.VehicleRouting.Encodings.Alba {
|
---|
36 | [Item("AlbaPushForwardCreator", "An operator which creates a new alba VRP representation using the push forward insertion heuristic.")]
|
---|
37 | [StorableClass]
|
---|
38 | public sealed class AlbaPushForwardCreator : VRPCreator, IStochasticOperator {
|
---|
39 | #region IStochasticOperator Members
|
---|
40 | public ILookupParameter<IRandom> RandomParameter {
|
---|
41 | get { return (LookupParameter<IRandom>)Parameters["Random"]; }
|
---|
42 | }
|
---|
43 | #endregion
|
---|
44 |
|
---|
45 | public IValueParameter<DoubleValue> Alpha {
|
---|
46 | get { return (IValueParameter<DoubleValue>)Parameters["Alpha"]; }
|
---|
47 | }
|
---|
48 | public IValueParameter<DoubleValue> AlphaVariance {
|
---|
49 | get { return (IValueParameter<DoubleValue>)Parameters["AlphaVariance"]; }
|
---|
50 | }
|
---|
51 | public IValueParameter<DoubleValue> Beta {
|
---|
52 | get { return (IValueParameter<DoubleValue>)Parameters["Beta"]; }
|
---|
53 | }
|
---|
54 | public IValueParameter<DoubleValue> BetaVariance {
|
---|
55 | get { return (IValueParameter<DoubleValue>)Parameters["BetaVariance"]; }
|
---|
56 | }
|
---|
57 | public IValueParameter<DoubleValue> Gamma {
|
---|
58 | get { return (IValueParameter<DoubleValue>)Parameters["Gamma"]; }
|
---|
59 | }
|
---|
60 | public IValueParameter<DoubleValue> GammaVariance {
|
---|
61 | get { return (IValueParameter<DoubleValue>)Parameters["GammaVariance"]; }
|
---|
62 | }
|
---|
63 |
|
---|
64 | public AlbaPushForwardCreator()
|
---|
65 | : base() {
|
---|
66 | Parameters.Add(new LookupParameter<IRandom>("Random", "The pseudo random number generator."));
|
---|
67 | Parameters.Add(new ValueParameter<DoubleValue>("Alpha", "The alpha value.", new DoubleValue(0.7)));
|
---|
68 | Parameters.Add(new ValueParameter<DoubleValue>("AlphaVariance", "The alpha variance.", new DoubleValue(0.5)));
|
---|
69 | Parameters.Add(new ValueParameter<DoubleValue>("Beta", "The beta value.", new DoubleValue(0.1)));
|
---|
70 | Parameters.Add(new ValueParameter<DoubleValue>("BetaVariance", "The beta variance.", new DoubleValue(0.07)));
|
---|
71 | Parameters.Add(new ValueParameter<DoubleValue>("Gamma", "The gamma value.", new DoubleValue(0.2)));
|
---|
72 | Parameters.Add(new ValueParameter<DoubleValue>("GammaVariance", "The gamma variance.", new DoubleValue(0.14)));
|
---|
73 | }
|
---|
74 |
|
---|
75 | public override IOperation Apply() {
|
---|
76 | VRPSolutionParameter.ActualValue = new AlbaEncoding(CreateSolution(), CitiesParameter.ActualValue.Value);
|
---|
77 |
|
---|
78 | return base.Apply();
|
---|
79 | }
|
---|
80 |
|
---|
81 | // use the Box-Mueller transform in the polar form to generate a N(0,1) random variable out of two uniformly distributed random variables
|
---|
82 | private double Gauss(IRandom random) {
|
---|
83 | double u = 0.0, v = 0.0, s = 0.0;
|
---|
84 | do {
|
---|
85 | u = (random.NextDouble() * 2) - 1;
|
---|
86 | v = (random.NextDouble() * 2) - 1;
|
---|
87 | s = Math.Sqrt(u * u + v * v);
|
---|
88 | } while (s < Double.Epsilon || s > 1);
|
---|
89 | return u * Math.Sqrt((-2.0 * Math.Log(s)) / s);
|
---|
90 | }
|
---|
91 |
|
---|
92 | private double N(double mu, double sigma, IRandom random) {
|
---|
93 | return mu + (sigma * Gauss(random)); // transform the random variable sampled from N(0,1) to N(mu,sigma)
|
---|
94 | }
|
---|
95 |
|
---|
96 | private double CalculateDistance(int start, int end) {
|
---|
97 | double distance = 0.0;
|
---|
98 | DoubleMatrix coordinates = CoordinatesParameter.ActualValue;
|
---|
99 |
|
---|
100 | distance =
|
---|
101 | Math.Sqrt(
|
---|
102 | Math.Pow(coordinates[start, 0] - coordinates[end, 0], 2) +
|
---|
103 | Math.Pow(coordinates[start, 1] - coordinates[end, 1], 2));
|
---|
104 |
|
---|
105 | return distance;
|
---|
106 | }
|
---|
107 |
|
---|
108 | private DoubleMatrix CreateDistanceMatrix() {
|
---|
109 | DoubleMatrix coordinates = CoordinatesParameter.ActualValue;
|
---|
110 | DoubleMatrix distanceMatrix = new DoubleMatrix(coordinates.Rows, coordinates.Rows);
|
---|
111 |
|
---|
112 | for (int i = 0; i < distanceMatrix.Rows; i++) {
|
---|
113 | for (int j = i; j < distanceMatrix.Columns; j++) {
|
---|
114 | double distance = CalculateDistance(i, j);
|
---|
115 |
|
---|
116 | distanceMatrix[i, j] = distance;
|
---|
117 | distanceMatrix[j, i] = distance;
|
---|
118 | }
|
---|
119 | }
|
---|
120 |
|
---|
121 | return distanceMatrix;
|
---|
122 | }
|
---|
123 |
|
---|
124 | private double Distance(int start, int end) {
|
---|
125 | double distance = 0.0;
|
---|
126 |
|
---|
127 | if (UseDistanceMatrixParameter.ActualValue.Value) {
|
---|
128 | if (DistanceMatrixParameter.ActualValue == null) {
|
---|
129 | DistanceMatrixParameter.ActualValue = CreateDistanceMatrix();
|
---|
130 | }
|
---|
131 |
|
---|
132 | distance = DistanceMatrixParameter.ActualValue[start, end];
|
---|
133 | } else {
|
---|
134 | distance = CalculateDistance(start, end);
|
---|
135 | }
|
---|
136 |
|
---|
137 | return distance;
|
---|
138 | }
|
---|
139 |
|
---|
140 | private double TravelDistance(List<int> route, int begin) {
|
---|
141 | double distance = 0;
|
---|
142 | for (int i = begin; i < route.Count - 1 && (i == begin || route[i] != 0); i++) {
|
---|
143 | distance += Distance(route[i], route[i + 1]);
|
---|
144 | }
|
---|
145 | return distance;
|
---|
146 | }
|
---|
147 |
|
---|
148 | private bool SubrouteConstraintsOK(List<int> route, int begin) {
|
---|
149 | double t = 0.0, o = 0.0;
|
---|
150 | for (int i = begin + 1; i < route.Count; i++) {
|
---|
151 | t += Distance(route[i - 1], route[i]);
|
---|
152 | if (route[i] == 0) return (t < DueTimeParameter.ActualValue[0]); // violation on capacity constraint is handled below
|
---|
153 | else {
|
---|
154 | if (t > DueTimeParameter.ActualValue[route[i]]) return false;
|
---|
155 | t = Math.Max(ReadyTimeParameter.ActualValue[route[i]], t);
|
---|
156 | t += ServiceTimeParameter.ActualValue[route[i]];
|
---|
157 | o += DemandParameter.ActualValue[route[i]];
|
---|
158 | if (o > CapacityParameter.ActualValue.Value) return false; // premature exit on capacity constraint violation
|
---|
159 | }
|
---|
160 | }
|
---|
161 | return true;
|
---|
162 | }
|
---|
163 |
|
---|
164 | private bool SubrouteTardinessOK(List<int> route, int begin) {
|
---|
165 | double t = 0.0;
|
---|
166 | for (int i = begin + 1; i < route.Count; i++) {
|
---|
167 | t += Distance(route[i - 1], route[i]);
|
---|
168 | if (route[i] == 0) {
|
---|
169 | if (t < DueTimeParameter.ActualValue[0]) return true;
|
---|
170 | else return false;
|
---|
171 | } else {
|
---|
172 | if (t > DueTimeParameter.ActualValue[route[i]]) return false;
|
---|
173 | t = Math.Max(ReadyTimeParameter.ActualValue[route[i]], t);
|
---|
174 | t += ServiceTimeParameter.ActualValue[route[i]];
|
---|
175 | }
|
---|
176 | }
|
---|
177 | return true;
|
---|
178 | }
|
---|
179 |
|
---|
180 | private bool SubrouteLoadOK(List<int> route, int begin) {
|
---|
181 | double o = 0.0;
|
---|
182 | for (int i = begin + 1; i < route.Count; i++) {
|
---|
183 | if (route[i] == 0) return (o < CapacityParameter.ActualValue.Value);
|
---|
184 | else {
|
---|
185 | o += DemandParameter.ActualValue[route[i]];
|
---|
186 | }
|
---|
187 | }
|
---|
188 | return (o < CapacityParameter.ActualValue.Value);
|
---|
189 | }
|
---|
190 |
|
---|
191 | private Permutation CreateSolution() {
|
---|
192 | double alpha, beta, gamma;
|
---|
193 | alpha = N(Alpha.Value.Value, Math.Sqrt(AlphaVariance.Value.Value), RandomParameter.ActualValue);
|
---|
194 | beta = N(Beta.Value.Value, Math.Sqrt(BetaVariance.Value.Value), RandomParameter.ActualValue);
|
---|
195 | gamma = N(Gamma.Value.Value, Math.Sqrt(GammaVariance.Value.Value), RandomParameter.ActualValue);
|
---|
196 |
|
---|
197 | double x0 = CoordinatesParameter.ActualValue[0,0];
|
---|
198 | double y0 = CoordinatesParameter.ActualValue[0,1];
|
---|
199 | double distance = 0;
|
---|
200 | double cost = 0;
|
---|
201 | double minimumCost = double.MaxValue;
|
---|
202 | List<int> unroutedList = new List<int>();
|
---|
203 | List<double> costList = new List<double>();
|
---|
204 | int index;
|
---|
205 | int indexOfMinimumCost = -1;
|
---|
206 | int indexOfCustomer = -1;
|
---|
207 |
|
---|
208 | /*-----------------------------------------------------------------------------
|
---|
209 | * generate cost list
|
---|
210 | *-----------------------------------------------------------------------------
|
---|
211 | */
|
---|
212 | for (int i = 1; i <= CitiesParameter.ActualValue.Value; i++) {
|
---|
213 | distance = Distance(i, 0);
|
---|
214 | if (CoordinatesParameter.ActualValue[i,0] < x0) distance = -distance;
|
---|
215 | cost = -alpha * distance + // distance 0 <-> City[i]
|
---|
216 | beta * (DueTimeParameter.ActualValue[i]) + // latest arrival time
|
---|
217 | gamma * (Math.Asin((CoordinatesParameter.ActualValue[i,1] - y0) / distance) / 360 * distance); // polar angle
|
---|
218 |
|
---|
219 | index = 0;
|
---|
220 | while (index < costList.Count && costList[index] < cost) index++;
|
---|
221 | costList.Insert(index, cost);
|
---|
222 | unroutedList.Insert(index, i);
|
---|
223 | }
|
---|
224 |
|
---|
225 | /*------------------------------------------------------------------------------
|
---|
226 | * route customers according to cost list
|
---|
227 | *------------------------------------------------------------------------------
|
---|
228 | */
|
---|
229 | int routeIndex = 0;
|
---|
230 | int currentRoute = 0;
|
---|
231 | int c;
|
---|
232 | int customer = -1;
|
---|
233 | int subTourCount = 1;
|
---|
234 | List<int> route = new List<int>(CitiesParameter.ActualValue.Value + VehiclesParameter.ActualValue.Value - 1);
|
---|
235 | minimumCost = double.MaxValue;
|
---|
236 | indexOfMinimumCost = -1;
|
---|
237 | route.Add(0);
|
---|
238 | route.Add(0);
|
---|
239 | route.Insert(1, unroutedList[0]);
|
---|
240 | unroutedList.RemoveAt(0);
|
---|
241 | currentRoute = routeIndex;
|
---|
242 | routeIndex++;
|
---|
243 |
|
---|
244 | do {
|
---|
245 | for (c = 0; c < unroutedList.Count; c++) {
|
---|
246 | for (int i = currentRoute + 1; i < route.Count; i++) {
|
---|
247 | route.Insert(i, (int)unroutedList[c]);
|
---|
248 | if (route[currentRoute] != 0) { throw new Exception("currentRoute not depot"); }
|
---|
249 | cost = TravelDistance(route, currentRoute);
|
---|
250 | if (cost < minimumCost && SubrouteConstraintsOK(route, currentRoute)) {
|
---|
251 | minimumCost = cost;
|
---|
252 | indexOfMinimumCost = i;
|
---|
253 | customer = (int)unroutedList[c];
|
---|
254 | indexOfCustomer = c;
|
---|
255 | }
|
---|
256 | route.RemoveAt(i);
|
---|
257 | }
|
---|
258 | }
|
---|
259 | // insert customer if found
|
---|
260 | if (indexOfMinimumCost != -1) {
|
---|
261 | route.Insert(indexOfMinimumCost, customer);
|
---|
262 | routeIndex++;
|
---|
263 | unroutedList.RemoveAt(indexOfCustomer);
|
---|
264 | costList.RemoveAt(indexOfCustomer);
|
---|
265 | } else { // no feasible customer found
|
---|
266 | routeIndex++;
|
---|
267 | route.Insert(routeIndex, 0);
|
---|
268 | currentRoute = routeIndex;
|
---|
269 | route.Insert(route.Count - 1, (int)unroutedList[0]);
|
---|
270 | unroutedList.RemoveAt(0);
|
---|
271 | routeIndex++;
|
---|
272 | subTourCount++;
|
---|
273 | }
|
---|
274 | // reset minimum
|
---|
275 | minimumCost = double.MaxValue;
|
---|
276 | indexOfMinimumCost = -1;
|
---|
277 | indexOfCustomer = -1;
|
---|
278 | customer = -1;
|
---|
279 | } while (unroutedList.Count > 0);
|
---|
280 | while (route.Count < CitiesParameter.ActualValue.Value + VehiclesParameter.ActualValue.Value - 1)
|
---|
281 | route.Add(0);
|
---|
282 |
|
---|
283 | int vehicle = CitiesParameter.ActualValue.Value;
|
---|
284 | for (int i = 0; i < route.Count; i++) {
|
---|
285 | if (route[i] == 0) {
|
---|
286 | route[i] = vehicle;
|
---|
287 | vehicle++;
|
---|
288 | } else {
|
---|
289 | route[i] = route[i] - 1;
|
---|
290 | }
|
---|
291 | }
|
---|
292 |
|
---|
293 | return new Permutation(PermutationTypes.RelativeDirected, route.ToArray());
|
---|
294 | }
|
---|
295 | }
|
---|
296 | }
|
---|