Changeset 15131 for stable/HeuristicLab.Algorithms.DataAnalysis/3.4/BaselineClassifiers

Timestamp:

07/06/17 10:19:37 (7 years ago)

Author:

gkronber

Message:

#2650: merged r14826 from trunk to stable. The only remaining conflict is DataTableControl and ScatterPlotControl which have been renamed within r14982 (-> tree conflict).

Location:

stable

Files:

• . (modified) (1 prop)
• HeuristicLab.Algorithms.DataAnalysis (modified) (1 prop)
• HeuristicLab.Algorithms.DataAnalysis/3.4/BaselineClassifiers/OneFactorClassificationModel.cs (copied) (copied from trunk/sources/HeuristicLab.Algorithms.DataAnalysis/3.4/BaselineClassifiers/OneFactorClassificationModel.cs)
• HeuristicLab.Algorithms.DataAnalysis/3.4/BaselineClassifiers/OneFactorClassificationSolution.cs (copied) (copied from trunk/sources/HeuristicLab.Algorithms.DataAnalysis/3.4/BaselineClassifiers/OneFactorClassificationSolution.cs)
• HeuristicLab.Algorithms.DataAnalysis/3.4/BaselineClassifiers/OneR.cs (modified) (6 diffs)
• HeuristicLab.Algorithms.DataAnalysis/3.4/BaselineClassifiers/OneRClassificationModel.cs (modified) (6 diffs)
• HeuristicLab.Algorithms.DataAnalysis/3.4/BaselineClassifiers/OneRClassificationSolution.cs (modified) (2 diffs)

stable/HeuristicLab.Algorithms.DataAnalysis/3.4/BaselineClassifiers/OneR.cs

@@ -20 +20 @@
 #endregion
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -65 +66 @@
 
     public static IClassificationSolution CreateOneRSolution(IClassificationProblemData problemData, int minBucketSize = 6) {
+      var classValues = problemData.Dataset.GetDoubleValues(problemData.TargetVariable, problemData.TrainingIndices);
+      var model1 = FindBestDoubleVariableModel(problemData, minBucketSize);
+      var model2 = FindBestFactorModel(problemData);
+
+      if (model1 == null && model2 == null) throw new InvalidProgramException("Could not create OneR solution");
+      else if (model1 == null) return new OneFactorClassificationSolution(model2, (IClassificationProblemData)problemData.Clone());
+      else if (model2 == null) return new OneRClassificationSolution(model1, (IClassificationProblemData)problemData.Clone());
+      else {
+        var model1EstimatedValues = model1.GetEstimatedClassValues(problemData.Dataset, problemData.TrainingIndices);
+        var model1NumCorrect = classValues.Zip(model1EstimatedValues, (a, b) => a.IsAlmost(b)).Count(e => e);
+
+        var model2EstimatedValues = model2.GetEstimatedClassValues(problemData.Dataset, problemData.TrainingIndices);
+        var model2NumCorrect = classValues.Zip(model2EstimatedValues, (a, b) => a.IsAlmost(b)).Count(e => e);
+
+        if (model1NumCorrect > model2NumCorrect) {
+          return new OneRClassificationSolution(model1, (IClassificationProblemData)problemData.Clone());
+        } else {
+          return new OneFactorClassificationSolution(model2, (IClassificationProblemData)problemData.Clone());
+        }
+      }
+    }
+
+    private static OneRClassificationModel FindBestDoubleVariableModel(IClassificationProblemData problemData, int minBucketSize = 6) {
       var bestClassified = 0;
       List<Split> bestSplits = null;
@@ -71 +95 @@
       var classValues = problemData.Dataset.GetDoubleValues(problemData.TargetVariable, problemData.TrainingIndices);
 
-      foreach (var variable in problemData.AllowedInputVariables) {
+      var allowedInputVariables = problemData.AllowedInputVariables.Where(problemData.Dataset.VariableHasType<double>);
+
+      if (!allowedInputVariables.Any()) return null;
+
+      foreach (var variable in allowedInputVariables) {
         var inputValues = problemData.Dataset.GetDoubleValues(variable, problemData.TrainingIndices);
         var samples = inputValues.Zip(classValues, (i, v) => new Sample(i, v)).OrderBy(s => s.inputValue);
 
-        var missingValuesDistribution = samples.Where(s => double.IsNaN(s.inputValue)).GroupBy(s => s.classValue).ToDictionary(s => s.Key, s => s.Count()).MaxItems(s => s.Value).FirstOrDefault();
+        var missingValuesDistribution = samples
+          .Where(s => double.IsNaN(s.inputValue)).GroupBy(s => s.classValue)
+          .ToDictionary(s => s.Key, s => s.Count())
+          .MaxItems(s => s.Value)
+          .FirstOrDefault();
 
         //calculate class distributions for all distinct inputValues
@@ -120 +152 @@
           while (sample.inputValue >= splits[splitIndex].thresholdValue)
             splitIndex++;
-          correctClassified += sample.classValue == splits[splitIndex].classValue ? 1 : 0;
+          correctClassified += sample.classValue.IsAlmost(splits[splitIndex].classValue) ? 1 : 0;
         }
         correctClassified += missingValuesDistribution.Value;
@@ -134 +166 @@
       //remove neighboring splits with the same class value
       for (int i = 0; i < bestSplits.Count - 1; i++) {
-        if (bestSplits[i].classValue == bestSplits[i + 1].classValue) {
+        if (bestSplits[i].classValue.IsAlmost(bestSplits[i + 1].classValue)) {
           bestSplits.Remove(bestSplits[i]);
           i--;
@@ -140 +172 @@
       }
 
-      var model = new OneRClassificationModel(problemData.TargetVariable, bestVariable, bestSplits.Select(s => s.thresholdValue).ToArray(), bestSplits.Select(s => s.classValue).ToArray(), bestMissingValuesClass);
-      var solution = new OneRClassificationSolution(model, (IClassificationProblemData)problemData.Clone());
-
-      return solution;
+      var model = new OneRClassificationModel(problemData.TargetVariable, bestVariable,
+        bestSplits.Select(s => s.thresholdValue).ToArray(),
+        bestSplits.Select(s => s.classValue).ToArray(), bestMissingValuesClass);
+
+      return model;
+    }
+    private static OneFactorClassificationModel FindBestFactorModel(IClassificationProblemData problemData) {
+      var classValues = problemData.Dataset.GetDoubleValues(problemData.TargetVariable, problemData.TrainingIndices);
+      var defaultClass = FindMostFrequentClassValue(classValues);
+      // only select string variables
+      var allowedInputVariables = problemData.AllowedInputVariables.Where(problemData.Dataset.VariableHasType<string>);
+
+      if (!allowedInputVariables.Any()) return null;
+
+      OneFactorClassificationModel bestModel = null;
+      var bestModelNumCorrect = 0;
+
+      foreach (var variable in allowedInputVariables) {
+        var variableValues = problemData.Dataset.GetStringValues(variable, problemData.TrainingIndices);
+        var groupedClassValues = variableValues
+          .Zip(classValues, (v, c) => new KeyValuePair<string, double>(v, c))
+          .GroupBy(kvp => kvp.Key)
+          .ToDictionary(g => g.Key, g => FindMostFrequentClassValue(g.Select(kvp => kvp.Value)));
+
+        var model = new OneFactorClassificationModel(problemData.TargetVariable, variable,
+          groupedClassValues.Select(kvp => kvp.Key).ToArray(), groupedClassValues.Select(kvp => kvp.Value).ToArray(), defaultClass);
+
+        var modelEstimatedValues = model.GetEstimatedClassValues(problemData.Dataset, problemData.TrainingIndices);
+        var modelNumCorrect = classValues.Zip(modelEstimatedValues, (a, b) => a.IsAlmost(b)).Count(e => e);
+        if (modelNumCorrect > bestModelNumCorrect) {
+          bestModelNumCorrect = modelNumCorrect;
+          bestModel = model;
+        }
+      }
+
+      return bestModel;
+    }
+
+    private static double FindMostFrequentClassValue(IEnumerable<double> classValues) {
+      return classValues.GroupBy(c => c).OrderByDescending(g => g.Count()).Select(g => g.Key).First();
     }
 

stable/HeuristicLab.Algorithms.DataAnalysis/3.4/BaselineClassifiers/OneRClassificationModel.cs

@@ -31 +31 @@
   [StorableClass]
   [Item("OneR Classification Model", "A model that uses intervals for one variable to determine the class.")]
-  public class OneRClassificationModel : ClassificationModel {
+  public sealed class OneRClassificationModel : ClassificationModel {
     public override IEnumerable<string> VariablesUsedForPrediction {
       get { return new[] { Variable }; }
@@ -37 +37 @@
 
     [Storable]
-    protected string variable;
+    private string variable;
     public string Variable {
       get { return variable; }
@@ -43 +43 @@
 
     [Storable]
-    protected double[] splits;
+    private double[] splits;
     public double[] Splits {
       get { return splits; }
@@ -49 +49 @@
 
     [Storable]
-    protected double[] classes;
+    private double[] classes;
     public double[] Classes {
       get { return classes; }
@@ -55 +55 @@
 
     [Storable]
-    protected double missingValuesClass;
+    private double missingValuesClass;
     public double MissingValuesClass {
       get { return missingValuesClass; }
@@ -61 +61 @@
 
     [StorableConstructor]
-    protected OneRClassificationModel(bool deserializing) : base(deserializing) { }
-    protected OneRClassificationModel(OneRClassificationModel original, Cloner cloner)
+    private OneRClassificationModel(bool deserializing) : base(deserializing) { }
+    private OneRClassificationModel(OneRClassificationModel original, Cloner cloner)
       : base(original, cloner) {
       this.variable = (string)original.variable;
       this.splits = (double[])original.splits.Clone();
       this.classes = (double[])original.classes.Clone();
+      this.missingValuesClass = original.missingValuesClass;
     }
     public override IDeepCloneable Clone(Cloner cloner) { return new OneRClassificationModel(this, cloner); }

stable/HeuristicLab.Algorithms.DataAnalysis/3.4/BaselineClassifiers/OneRClassificationSolution.cs

@@ -28 +28 @@
   [StorableClass]
   [Item(Name = "OneR Classification Solution", Description = "Represents a OneR classification solution which uses only a single feature with potentially multiple thresholds for class prediction.")]
-  public class OneRClassificationSolution : ClassificationSolution {
+  public sealed class OneRClassificationSolution : ClassificationSolution {
     public new OneRClassificationModel Model {
       get { return (OneRClassificationModel)base.Model; }
@@ -35 +35 @@
 
     [StorableConstructor]
-    protected OneRClassificationSolution(bool deserializing) : base(deserializing) { }
-    protected OneRClassificationSolution(OneRClassificationSolution original, Cloner cloner) : base(original, cloner) { }
+    private OneRClassificationSolution(bool deserializing) : base(deserializing) { }
+    private OneRClassificationSolution(OneRClassificationSolution original, Cloner cloner) : base(original, cloner) { }
     public OneRClassificationSolution(OneRClassificationModel model, IClassificationProblemData problemData)
       : base(model, problemData) {