Changeset 8126 for trunk/sources/HeuristicLab.Problems.DataAnalysis/3.4/Implementation/Classification/ThresholdCalculators

Timestamp:

06/26/12 15:29:45 (12 years ago)

Author:

gkronber

Message:

#1823 fixed a bug in the Pareto-best solution analyzers for symbolic data analysis. Fixed a minor bug in the calculation of classification thresholds, made a sneaky change in SymbolicExpressionTree

File:

• trunk/sources/HeuristicLab.Problems.DataAnalysis/3.4/Implementation/Classification/ThresholdCalculators/AccuracyMaximizationThresholdCalculator.cs (modified) (2 diffs)

trunk/sources/HeuristicLab.Problems.DataAnalysis/3.4/Implementation/Classification/ThresholdCalculators/AccuracyMaximizationThresholdCalculator.cs

@@ -54 +54 @@
     public static void CalculateThresholds(IClassificationProblemData problemData, IEnumerable<double> estimatedValues, IEnumerable<double> targetClassValues, out double[] classValues, out double[] thresholds) {
       int slices = 100;
+      double minThresholdInc = 10e-5; // necessary to prevent infinite loop when maxEstimated - minEstimated is effectively zero (constant model)
       List<double> estimatedValuesList = estimatedValues.ToList();
       double maxEstimatedValue = estimatedValuesList.Max();
       double minEstimatedValue = estimatedValuesList.Min();
-      double thresholdIncrement = (maxEstimatedValue - minEstimatedValue) / slices;
+      double thresholdIncrement = Math.Max((maxEstimatedValue - minEstimatedValue) / slices, minThresholdInc);
       var estimatedAndTargetValuePairs =
         estimatedValuesList.Zip(targetClassValues, (x, y) => new { EstimatedValue = x, TargetClassValue = y })
@@ -70 +71 @@
 
       // incrementally calculate accuracy of all possible thresholds
-      int[,] confusionMatrix = new int[nClasses, nClasses];
-
       for (int i = 1; i < thresholds.Length; i++) {
         double lowerThreshold = thresholds[i - 1];