Changeset 7677 for trunk/sources/HeuristicLab.Problems.DataAnalysis.Symbolic.Regression/3.4/SingleObjective/Evaluators/SymbolicRegressionSingleObjectiveEvaluator.cs

Timestamp:

03/30/12 22:48:32 (12 years ago)

Author:

mkommend

Message:

#1788: Implemente new symbolic regression evaluators.

File:

• trunk/sources/HeuristicLab.Problems.DataAnalysis.Symbolic.Regression/3.4/SingleObjective/Evaluators/SymbolicRegressionSingleObjectiveEvaluator.cs (modified) (2 diffs)

trunk/sources/HeuristicLab.Problems.DataAnalysis.Symbolic.Regression/3.4/SingleObjective/Evaluators/SymbolicRegressionSingleObjectiveEvaluator.cs

@@ -20 +20 @@
 #endregion
 
-
+using System;
+using System.Collections.Generic;
 using HeuristicLab.Common;
 using HeuristicLab.Core;
@@ -54 +55 @@
       }
     }
+
+    [ThreadStatic]
+    private static double[] cache;
+
+    protected static void CalculateWithScaling(IEnumerable<double> targetValues, IEnumerable<double> estimatedValues, IOnlineCalculator calculator, int maxRows) {
+      if (cache == null || cache.GetLength(0) < maxRows) {
+        cache = new double[maxRows];
+      }
+
+      //calculate linear scaling
+      //the static methods of the calculator could not be used as it performs a check if the enumerators have an equal amount of elements
+      //this is not true if the cache is used
+      int i = 0;
+      var linearScalingCalculator = new OnlineLinearScalingParameterCalculator();
+      var targetValuesEnumerator = targetValues.GetEnumerator();
+      var estimatedValuesEnumerator = estimatedValues.GetEnumerator();
+      while (targetValuesEnumerator.MoveNext() && estimatedValuesEnumerator.MoveNext()) {
+        double target = targetValuesEnumerator.Current;
+        double estimated = estimatedValuesEnumerator.Current;
+        cache[i] = estimated;
+        linearScalingCalculator.Add(estimated, target);
+        i++;
+      }
+      double alpha = linearScalingCalculator.Alpha;
+      double beta = linearScalingCalculator.Beta;
+
+      //calculate the quality by using the passed online calculator
+      targetValuesEnumerator = targetValues.GetEnumerator();
+      i = 0;
+      while (targetValuesEnumerator.MoveNext()) {
+        double target = targetValuesEnumerator.Current;
+        double estimated = cache[i] * beta + alpha;
+        calculator.Add(target, estimated);
+        i++;
+      }
+    }
   }
 }