Changeset 17975 for stable/HeuristicLab.Encodings.SymbolicExpressionTreeEncoding/3.4/Crossovers

Timestamp:

05/06/21 12:14:02 (4 years ago)

Author:

gkronber

Message:

#3067: merged r17490:17492 and r17871:17872 from trunk to stable

Location:

stable

Files:

• . (modified) (1 prop)
• HeuristicLab.Encodings.SymbolicExpressionTreeEncoding (modified) (1 prop)
• HeuristicLab.Encodings.SymbolicExpressionTreeEncoding/3.4/Crossovers/SubtreeCrossover.cs (modified) (6 diffs)

stable/HeuristicLab.Encodings.SymbolicExpressionTreeEncoding/3.4/Crossovers/SubtreeCrossover.cs

@@ -43 +43 @@
     private const string MaximumSymbolicExpressionTreeLengthParameterName = "MaximumSymbolicExpressionTreeLength";
     private const string MaximumSymbolicExpressionTreeDepthParameterName = "MaximumSymbolicExpressionTreeDepth";
+    private const string CrossoverProbabilityParameterName = "CrossoverProbability";
 
     #region Parameter Properties
@@ -53 +54 @@
     public IValueLookupParameter<IntValue> MaximumSymbolicExpressionTreeDepthParameter {
       get { return (IValueLookupParameter<IntValue>)Parameters[MaximumSymbolicExpressionTreeDepthParameterName]; }
+    }
+    public IFixedValueParameter<PercentValue> CrossoverProbabilityParameter {
+      get { return (IFixedValueParameter<PercentValue>)Parameters[CrossoverProbabilityParameterName]; }
     }
     #endregion
@@ -64 +68 @@
     public IntValue MaximumSymbolicExpressionTreeDepth {
       get { return MaximumSymbolicExpressionTreeDepthParameter.ActualValue; }
+    }
+    public double CrossoverProbability {
+      get { return CrossoverProbabilityParameter.Value.Value; }
+      set { CrossoverProbabilityParameter.Value.Value = value; }
     }
     #endregion
@@ -73 +81 @@
       Parameters.Add(new ValueLookupParameter<IntValue>(MaximumSymbolicExpressionTreeLengthParameterName, "The maximal length (number of nodes) of the symbolic expression tree."));
       Parameters.Add(new ValueLookupParameter<IntValue>(MaximumSymbolicExpressionTreeDepthParameterName, "The maximal depth of the symbolic expression tree (a tree with one node has depth = 0)."));
-      Parameters.Add(new ValueLookupParameter<PercentValue>(InternalCrossoverPointProbabilityParameterName, "The probability to select an internal crossover point (instead of a leaf node).", new PercentValue(0.9)));
+      Parameters.Add(new ValueLookupParameter<PercentValue>(InternalCrossoverPointProbabilityParameterName, "The probability to select an internal crossover point (instead of a leaf node).", new PercentValue(0.9, true)));
+      Parameters.Add(new FixedValueParameter<PercentValue>(CrossoverProbabilityParameterName, "The probability that a crossover is performed. Otherwise a copy of the first parent is returned.", new PercentValue(1, true)));
+    }
+
+    [StorableHook(HookType.AfterDeserialization)]
+    private void AfterDeserialization() {
+      // replace with PercentValue for files which had CrossoverProbability as DoubleValue
+      if (Parameters.ContainsKey(CrossoverProbabilityParameterName) && (Parameters[CrossoverProbabilityParameterName] is IFixedValueParameter<DoubleValue> oldParam)) {
+        var oldValue = oldParam.Value.Value;
+        Parameters.Remove(oldParam);
+        Parameters.Add(new FixedValueParameter<PercentValue>(CrossoverProbabilityParameterName, "The probability that a crossover is performed. Otherwise a copy of the first parent is returned.", new PercentValue(oldValue)));
+      }
+      if (!Parameters.ContainsKey(CrossoverProbabilityParameterName)) {
+        Parameters.Add(new FixedValueParameter<PercentValue>(CrossoverProbabilityParameterName, "The probability that a crossover is performed. Otherwise a copy of the first parent is returned.", new PercentValue(1, true)));
+      }
     }
 
@@ -82 +104 @@
     public override ISymbolicExpressionTree Crossover(IRandom random,
       ISymbolicExpressionTree parent0, ISymbolicExpressionTree parent1) {
-      return Cross(random, parent0, parent1, InternalCrossoverPointProbability.Value,
+      return Cross(random, parent0, parent1, CrossoverProbability, InternalCrossoverPointProbability.Value,
         MaximumSymbolicExpressionTreeLength.Value, MaximumSymbolicExpressionTreeDepth.Value);
     }
@@ -88 +110 @@
     public static ISymbolicExpressionTree Cross(IRandom random,
       ISymbolicExpressionTree parent0, ISymbolicExpressionTree parent1,
+      double probability,
       double internalCrossoverPointProbability, int maxTreeLength, int maxTreeDepth) {
+      if ((probability < 1) && (random.NextDouble() >= probability)) return parent0;
       // select a random crossover point in the first parent 
       CutPoint crossoverPoint0;