1 | #region License Information
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2 | /* HeuristicLab
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3 | * Copyright (C) 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.Linq;
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24 | using System.Threading;
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25 | using HeuristicLab.Common;
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26 | using HeuristicLab.Core;
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27 | using HeuristicLab.Data;
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28 | using HeuristicLab.Parameters;
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29 | using HeuristicLab.Problems.DataAnalysis;
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30 | using HEAL.Attic;
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31 |
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32 | namespace HeuristicLab.Algorithms.DataAnalysis {
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33 | [StorableType("852B9F7D-9C2B-4574-BB71-EE70106EA809")]
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34 | [Item("GaussianProcessLeaf", "A leaf type that uses Gaussian process models as leaf models.")]
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35 | public class GaussianProcessLeaf : LeafBase {
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36 | #region ParameterNames
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37 | public const string TriesParameterName = "Tries";
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38 | public const string RegressionParameterName = "Regression";
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39 | #endregion
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40 |
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41 | #region ParameterProperties
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42 | public IFixedValueParameter<IntValue> TriesParameter {
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43 | get { return (IFixedValueParameter<IntValue>)Parameters[TriesParameterName]; }
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44 | }
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45 | public IValueParameter<GaussianProcessRegression> RegressionParameter {
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46 | get { return (IValueParameter<GaussianProcessRegression>)Parameters[RegressionParameterName]; }
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47 | }
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48 | #endregion
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49 |
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50 | #region Properties
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51 | public int Tries {
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52 | get { return TriesParameter.Value.Value; }
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53 | set { TriesParameter.Value.Value = value; }
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54 | }
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55 | public GaussianProcessRegression Regression {
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56 | get { return RegressionParameter.Value; }
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57 | set { RegressionParameter.Value = value; }
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58 | }
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59 | #endregion
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60 |
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61 | #region Constructors & Cloning
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62 | [StorableConstructor]
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63 | protected GaussianProcessLeaf(StorableConstructorFlag _) : base(_) { }
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64 | protected GaussianProcessLeaf(GaussianProcessLeaf original, Cloner cloner) : base(original, cloner) { }
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65 | public GaussianProcessLeaf() {
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66 | var gp = new GaussianProcessRegression();
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67 | gp.CovarianceFunctionParameter.Value = new CovarianceRationalQuadraticIso();
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68 | gp.MeanFunctionParameter.Value = new MeanLinear();
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69 |
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70 | Parameters.Add(new FixedValueParameter<IntValue>(TriesParameterName, "Number of restarts (default = 10)", new IntValue(10)));
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71 | Parameters.Add(new ValueParameter<GaussianProcessRegression>(RegressionParameterName, "The algorithm creating Gaussian process models", gp));
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72 | }
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73 | public override IDeepCloneable Clone(Cloner cloner) {
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74 | return new GaussianProcessLeaf(this, cloner);
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75 | }
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76 | #endregion
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77 |
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78 | #region IModelType
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79 | public override bool ProvidesConfidence {
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80 | get { return true; }
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81 | }
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82 |
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83 | public override IRegressionModel Build(IRegressionProblemData pd, IRandom random, CancellationToken cancellationToken, out int numberOfParameters) {
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84 | if (pd.Dataset.Rows < MinLeafSize(pd)) throw new ArgumentException("The number of training instances is too small to create a Gaussian process model");
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85 | Regression.Problem = new RegressionProblem { ProblemData = pd };
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86 | var cvscore = double.MaxValue;
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87 | GaussianProcessRegressionSolution sol = null;
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88 |
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89 | for (var i = 0; i < Tries; i++) {
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90 | var res = RegressionTreeUtilities.RunSubAlgorithm(Regression, random.Next(), cancellationToken);
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91 | var t = res.Select(x => x.Value).OfType<GaussianProcessRegressionSolution>().FirstOrDefault();
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92 | var score = ((DoubleValue)res["Negative log pseudo-likelihood (LOO-CV)"].Value).Value;
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93 | if (score >= cvscore || t == null || double.IsNaN(t.TrainingRSquared)) continue;
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94 | cvscore = score;
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95 | sol = t;
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96 | }
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97 | Regression.Runs.Clear();
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98 | if (sol == null) throw new ArgumentException("Could not create Gaussian process model");
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99 |
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100 | numberOfParameters = pd.Dataset.Rows + 1
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101 | + Regression.CovarianceFunction.GetNumberOfParameters(pd.AllowedInputVariables.Count())
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102 | + Regression.MeanFunction.GetNumberOfParameters(pd.AllowedInputVariables.Count());
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103 | return sol.Model;
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104 | }
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105 |
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106 | public override int MinLeafSize(IRegressionProblemData pd) {
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107 | return 3;
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108 | }
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109 | #endregion
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110 | }
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111 | } |
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