Changeset 5326 for trunk/sources/HeuristicLab.Problems.DataAnalysis/3.3/Symbolic/Symbols/VariableTreeNode.cs

Timestamp:

01/18/11 16:09:35 (14 years ago)

Author:

gkronber

Message:

Implemented multiplicative manipulation of constants and variable weights. #1384

File:

• trunk/sources/HeuristicLab.Problems.DataAnalysis/3.3/Symbolic/Symbols/VariableTreeNode.cs (modified) (1 diff)

trunk/sources/HeuristicLab.Problems.DataAnalysis/3.3/Symbolic/Symbols/VariableTreeNode.cs

@@ -68 +68 @@
     public override void ShakeLocalParameters(IRandom random, double shakingFactor) {
       base.ShakeLocalParameters(random, shakingFactor);
-      double x = NormalDistributedRandom.NextDouble(random, Symbol.WeightManipulatorMu, Symbol.WeightManipulatorSigma);
-      weight = weight + x * shakingFactor;
+      // 50% additive & 50% multiplicative
+      if (random.NextDouble() < 0) {
+        double x = NormalDistributedRandom.NextDouble(random, Symbol.WeightManipulatorMu, Symbol.WeightManipulatorSigma);
+        weight = weight + x * shakingFactor;
+      } else {        
+        double x = NormalDistributedRandom.NextDouble(random, 1.0, Symbol.MultiplicativeWeightManipulatorSigma);
+        weight = weight * x;
+      }
       variableName = Symbol.VariableNames.SelectRandom(random);
     }