[3996] | 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 System.Linq;
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| 25 | using System.Text;
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| 26 | using HeuristicLab.Common;
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| 27 | using HeuristicLab.Core;
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| 28 | using HeuristicLab.Data;
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| 29 | using HeuristicLab.Parameters;
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| 30 |
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| 31 | namespace HeuristicLab.Problems.DataAnalysis.Evaluators {
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| 32 | public class OnlinePearsonsRSquaredEvaluator : IOnlineEvaluator {
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| 33 |
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| 34 | private double sum_sq_x;
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| 35 | private double sum_sq_y;
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| 36 | private double sum_coproduct;
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| 37 | private double mean_x;
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| 38 | private double mean_y;
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| 39 | private int n;
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| 40 |
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| 41 | public double RSquared {
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| 42 | get {
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| 43 | if (n < 1)
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| 44 | throw new InvalidOperationException("No elements");
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| 45 | else {
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| 46 | double pop_sd_x = Math.Sqrt(sum_sq_x / n);
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| 47 | double pop_sd_y = Math.Sqrt(sum_sq_y / n);
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| 48 | double cov_x_y = sum_coproduct / n;
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| 49 |
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| 50 | if (pop_sd_x.IsAlmost(0.0) || pop_sd_y.IsAlmost(0.0))
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| 51 | return 0.0;
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| 52 | else {
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| 53 | double r = cov_x_y / (pop_sd_x * pop_sd_y);
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| 54 | return r * r;
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| 55 | }
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| 56 | }
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| 57 | }
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| 58 | }
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| 59 |
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| 60 | public OnlinePearsonsRSquaredEvaluator() { }
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| 61 |
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| 62 | #region IOnlineEvaluator Members
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[4022] | 63 | public double Value {
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| 64 | get { return RSquared; }
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| 65 | }
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[3996] | 66 | public void Reset() {
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| 67 | sum_sq_x = 0.0;
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| 68 | sum_sq_y = 0.0;
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| 69 | sum_coproduct = 0.0;
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| 70 | mean_x = 0.0;
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| 71 | mean_y = 0.0;
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| 72 | n = 0;
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| 73 | }
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| 74 |
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| 75 | public void Add(double original, double estimated) {
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| 76 | // stable and iterative calculation of R²
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| 77 | if (IsInvalidValue(original) || IsInvalidValue(estimated)) {
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| 78 | throw new ArgumentException("R² is not defined for variables with NaN or infinity values.");
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| 79 | }
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| 80 | if (n == 0) {
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| 81 | mean_x = original;
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| 82 | mean_y = estimated;
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| 83 | n = 1;
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| 84 | } else {
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| 85 | double sweep = (n - 1.0) / n;
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| 86 | double delta_x = original - mean_x;
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| 87 | double delta_y = estimated - mean_y;
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| 88 | sum_sq_x += delta_x * delta_x * sweep;
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| 89 | sum_sq_y += delta_y * delta_y * sweep;
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| 90 | sum_coproduct += delta_x * delta_y * sweep;
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| 91 | mean_x += delta_x / n;
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| 92 | mean_y += delta_y / n;
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| 93 | n++;
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| 94 | }
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| 95 | }
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| 96 |
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| 97 | #endregion
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| 98 |
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| 99 | private bool IsInvalidValue(double x) {
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| 100 | return double.IsNaN(x) || double.IsInfinity(x);
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| 101 | }
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| 102 | }
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| 103 | }
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