Changeset 1218 for trunk/sources/HeuristicLab.RealVector/ContinuousCrossover.cs

Timestamp:

02/16/09 01:21:53 (16 years ago)

Author:

swagner

Message:

Refactoring of crossover operators (#470)

File:

• trunk/sources/HeuristicLab.RealVector/ContinuousCrossover.cs (modified) (3 diffs)

trunk/sources/HeuristicLab.RealVector/ContinuousCrossover.cs

@@ -28 +28 @@
 namespace HeuristicLab.RealVector {
   /// <summary>
-  /// Continuous crossover for real vectors: for each element randomly either the element of the first
-  /// parent or the average of both parents is selected.
+  /// Continuous crossover for real vectors: for each element either the element of the first
+  /// parent or the average of all parents is selected randomly.
   /// </summary>
   public class ContinuousCrossover : RealVectorCrossoverBase {
@@ -38 +38 @@
 
     /// <summary>
-    /// Performs a continuous crossover of the two given real vectors.
+    /// Performs a continuous crossover of multiple given real vectors.
     /// </summary>
     /// <param name="random">The random number generator.</param>
-    /// <param name="parent1">The first parent for the crossover.</param>
-    /// <param name="parent2">The second parent for the crossover.</param>
+    /// <param name="parents">An array containing the parents that should be crossed.</param>
     /// <returns>The newly created real vector, resulting from the continuous crossover.</returns>
-    public static double[] Apply(IRandom random, double[] parent1, double[] parent2) {
-      int length = parent1.Length;
+    public static double[] Apply(IRandom random, double[][] parents) {
+      int length = parents[0].Length;
       double[] result = new double[length];
 
       for (int i = 0; i < length; i++) {
         if (random.NextDouble() < 0.5) {
-          result[i] = (parent1[i] + parent2[i]) / 2;
+          double sum = 0.0;
+          for (int j = 0; j < parents.Length; j++)
+            sum += parents[j][i];
+          result[i] = sum / parents.Length;
         } else {
-          result[i] = parent1[i];
+          result[i] = parents[0][i];
         }
       }
@@ -59 +61 @@
 
     /// <summary>
-    /// Performs a continuous crossover of the two given real vectors.
+    /// Performs a continuous crossover operation for multiple given parent real vectors.
     /// </summary>
-    /// <remarks>Calls <see cref="Apply"/>.</remarks>
+    /// <exception cref="InvalidOperationException">Thrown if there are less than two parents.</exception>
     /// <param name="scope">The current scope.</param>
-    /// <param name="random">The random number generator.</param>
-    /// <param name="parent1">The first parent for the crossover.</param>
-    /// <param name="parent2">The second parent for the crossover.</param>
-    /// <returns>The newly created real vector, resulting from the continuous crossover.</returns>
-    protected override double[] Cross(IScope scope, IRandom random, double[] parent1, double[] parent2) {
-      return Apply(random, parent1, parent2);
+    /// <param name="random">A random number generator.</param>
+    /// <param name="parents">An array containing the real vectors that should be crossed.</param>
+    /// <returns>The newly created real vector, resulting from the crossover operation.</returns>
+    protected override double[] Cross(IScope scope, IRandom random, double[][] parents) {
+      if (parents.Length < 2) throw new InvalidOperationException("ERROR in ContinuousCrossover: The number of parents is less than 2");
+      return Apply(random, parents);
     }
   }