[13484] | 1 | #region License Information
|
---|
| 2 | /* HeuristicLab
|
---|
[16140] | 3 | * Copyright (C) 2002-2018 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
|
---|
[13484] | 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 |
|
---|
| 26 | namespace HeuristicLab.Problems.Instances.TSPLIB {
|
---|
| 27 | public class TSPLIBHeterogeneousPTSPInstanceProvider : TSPLIBPTSPInstanceProvider {
|
---|
| 28 |
|
---|
| 29 | public override string Name {
|
---|
| 30 | get { return "TSPLIB (heterogeneous symmetric PTSP)"; }
|
---|
| 31 | }
|
---|
| 32 |
|
---|
| 33 | public override IEnumerable<IDataDescriptor> GetDataDescriptors() {
|
---|
| 34 | foreach (var desc in base.GetDataDescriptors().OfType<TSPLIBDataDescriptor>()) {
|
---|
| 35 | desc.SolutionIdentifier = null;
|
---|
| 36 | yield return desc;
|
---|
| 37 | }
|
---|
| 38 | }
|
---|
| 39 |
|
---|
| 40 | protected override double[] GetProbabilities(IDataDescriptor descriptor, PTSPData instance) {
|
---|
| 41 | var random = new MarsagliaRandom(GetInstanceHash(instance.Name));
|
---|
| 42 | return Enumerable.Range(0, instance.Dimension).Select(_ => (int)Math.Round((0.1 + 0.9 * random.NextDouble()) * 100) / 100.0).ToArray();
|
---|
| 43 | }
|
---|
| 44 |
|
---|
| 45 | // Bernstein's hash function
|
---|
| 46 | private uint GetInstanceHash(string name) {
|
---|
| 47 | uint hash = 5381;
|
---|
| 48 | var len = name.Length;
|
---|
| 49 | for (var i = 0; i < len; i++)
|
---|
| 50 | unchecked { hash = ((hash * 33) + name[i]); }
|
---|
| 51 | return hash;
|
---|
| 52 | }
|
---|
| 53 |
|
---|
| 54 | /// <summary>
|
---|
| 55 | /// This class is used to randomly generate PTSP instances given the TSPLIB instances.
|
---|
| 56 | /// An own implementation of a RNG was used in order to avoid possible implementation changes
|
---|
| 57 | /// in future .NET versions which would result in entirely different instances.
|
---|
| 58 | /// </summary>
|
---|
| 59 | /// <remarks>
|
---|
| 60 | /// RNG is implemented according to George Marsaglia https://en.wikipedia.org/wiki/Multiply-with-carry
|
---|
| 61 | /// </remarks>
|
---|
| 62 | private class MarsagliaRandom {
|
---|
| 63 | /*
|
---|
| 64 | * S = 2111111111*X[n-4] + 1492*X[n-3] + 1776*X[n-2] + 5115*X[n-1] + C
|
---|
| 65 | * X[n] = S modulo 2^32
|
---|
| 66 | * C = floor(S / 2^32)
|
---|
| 67 | *
|
---|
| 68 | */
|
---|
| 69 | private readonly uint[] mem = new uint[4];
|
---|
| 70 | private uint c;
|
---|
| 71 |
|
---|
| 72 | public MarsagliaRandom(uint s) {
|
---|
| 73 | int i;
|
---|
| 74 | for (i = 0; i < mem.Length; i++) {
|
---|
| 75 | unchecked { s = s * 31294061 + 1; }
|
---|
| 76 | mem[i] = s;
|
---|
| 77 | }
|
---|
| 78 | unchecked { c = s * 31294061 + 1; }
|
---|
| 79 | }
|
---|
| 80 |
|
---|
| 81 | private uint Next() {
|
---|
| 82 | unchecked {
|
---|
| 83 | ulong wsum = 2111111111 * mem[0]
|
---|
| 84 | + 1492 * mem[1]
|
---|
| 85 | + 1776 * mem[2]
|
---|
| 86 | + 5115 * mem[3]
|
---|
| 87 | + c;
|
---|
| 88 |
|
---|
| 89 | mem[0] = mem[1];
|
---|
| 90 | mem[1] = mem[2];
|
---|
| 91 | mem[2] = mem[3];
|
---|
| 92 | mem[3] = (uint)wsum;
|
---|
| 93 | c = (uint)(wsum >> 32);
|
---|
| 94 | return mem[3];
|
---|
| 95 | }
|
---|
| 96 | }
|
---|
| 97 |
|
---|
| 98 | public double NextDouble() {
|
---|
| 99 | return (double)Next() / uint.MaxValue;
|
---|
| 100 | }
|
---|
| 101 | }
|
---|
| 102 | }
|
---|
| 103 | }
|
---|