Changed Node and Breaker to implement crossover.

Added crossover test sketch

lib/Breaker.pde

@@ -7,20 +7,30 @@ class Breaker {
   Breaker(CodeToolkit tk) {
     this.tk = tk;
     root = new Node(tk);
-    train();
+    train(null, null);
+    root.shrink();
+    root.triangleOpt();
+    computeFitness();
+  }
+  
+  Breaker(CodeToolkit tk, Breaker parent1, Breaker parent2) {
+    this.tk = tk;
+    root = new Node(tk);
+    root.guess = (random(1) < 0.5 ? parent1 : parent2).root.guess;
+    train(parent1.root, parent2.root);
     root.shrink();
     root.triangleOpt();
     computeFitness();
   }
 
-  void train() {
+  void train(Node p1, Node p2) {
     boolean[] used = new boolean[tk.M];
     int[] unused = new int[tk.M];
     for (int code = 0; code < tk.M; code++) {
       for (int k = 0; k < tk.M; k++) {
         used[k] = false;
       }
-      root.followPath(code, used, unused);
+      root.followPath(code, p1, p2, used, unused);
     }
   }
 

lib/Node.pde

@@ -4,21 +4,30 @@ class Node {
   int guess;
   boolean good;
   Node[] children;
+  // used for visualisation of crossover
+  // 0 = new, 1 = parent 1, 2 = parent2
+  int comesFrom;
 
   Node(CodeToolkit tk) {
     this.tk = tk;
     guess = int(random(tk.M));
     good = false;
     children = new Node[tk.F];
+    comesFrom = 0;
   }
 
-  void followPath(int code, boolean[] used, int[] unused) {
+  void followPath(int code, Node p1, Node p2, boolean[] used, int[] unused) {
     used[guess] = true;
     int f = tk.feedback(code, guess);
     if (f == 0) {
       good = true;
-    } else if (children[f] != null) {
-      children[f].followPath(code, used, unused);
+      return;
+    } 
+    Node p1Child = p1 == null ? null : p1.children[f];
+    Node p2Child = p2 == null ? null : p2.children[f];
+    children[f] = chooseChild(children[f], p1Child, p2Child, used);
+    if (children[f] != null) {
+      children[f].followPath(code, p1Child, p2Child, used, unused);
     } else {
       int count = 0;
       for (int k = 0; k < tk.M; k++) {
@@ -31,6 +40,27 @@ class Node {
     }
   }
 
+  Node chooseChild(Node myChild, Node p1Child, Node p2Child, boolean[] used) {
+    if (myChild != null) return myChild;
+    boolean can1 = p1Child != null && !used[p1Child.guess];
+    boolean can2 = p2Child != null && !used[p2Child.guess];
+    if (can1 && can2) {
+      if (random(1) < 0.5) {
+        can1 = false;
+      } else {
+        can2 = false;
+      }
+    }
+    Node choice = null;
+    if (can1 || can2) {
+      choice = new Node(tk);
+      choice.guess = (can1 ? p1Child : p2Child).guess; // No way! ;)
+      choice.comesFrom = can1 ? 1 : 2;
+      return choice;
+    }
+    return choice;
+  }
+
   void buildPath(int code, int[] unused, int count) {
     int k = int(random(count));
     guess = unused[k];
@@ -43,7 +73,7 @@ class Node {
       children[f].buildPath(code, unused, count - 1);
     }
   }
-  
+
   Node shrink() {
     int childCount = 0;
     Node lastChild = null;
@@ -56,7 +86,7 @@ class Node {
     }
     return !good && childCount == 1 ? lastChild : this;
   }
-  
+
   int triangleOpt() {
     int count = 0;
     int f1 = 0;
@@ -90,7 +120,7 @@ class Node {
     }
     return count;
   }
-  
+
   int height() {
     int h = 0;
     for (Node child : children) {
@@ -98,7 +128,7 @@ class Node {
     }
     return 1 + h;
   }
-  
+
   void histogram(int level, int[] histo) {
     if (good) histo[level]++;
     for (Node child : children) {
@@ -134,6 +164,11 @@ class Node {
       while (children[f] == null) f++;
       int x1 = (xc.get(i - 1) + xc.get(i)) / 2;
       stroke(0);
+      if (children[f].comesFrom == 1) {
+        stroke(255, 64, 0);
+      } else if (children[f].comesFrom == 2) {
+        stroke(0, 64, 255);
+      }
       line(x0, y + pegSize, x1, y + BRANCH_HEIGHT * pegSize);
       displayLabel(f, (x0 + x1) / 2.0, y + (BRANCH_HEIGHT + 1) / 2.0 * pegSize, pegSize);
       f++;

sketchbook/crossover/Breaker.pde

+../../lib/Breaker.pde
\ No newline at end of file

sketchbook/crossover/CodeToolkit.pde

+../../lib/CodeToolkit.pde
\ No newline at end of file

sketchbook/crossover/Node.pde

+../../lib/Node.pde
\ No newline at end of file

sketchbook/crossover/crossover.pde

+CodeToolkit tk = new CodeToolkit(3, 3);
+
+void setup() {
+  size(1540, 660);
+  background(255);
+  randomSeed(1972);
+  Breaker parent1 = new Breaker(tk);
+  parent1.display(0, 10, 10);
+  
+  stroke(0);
+  line(0, 330, width, 330);
+  line(730, 0, 730, 330);
+  
+  Breaker parent2 = new Breaker(tk);
+  parent2.display(740, 10, 10);
+
+  Breaker child1 = new Breaker(tk, parent1, parent2);
+  child1.display(0, 340, 10);
+  
+  stroke(0);
+  line(770, 330, 770, 660);
+  
+  Breaker child2 = new Breaker(tk, parent1, parent2);
+  child2.display(780, 340, 10);
+  
+  textSize(20);
+  textAlign(LEFT, TOP);
+  fill(255, 64, 0);
+  text(String.format("Parent1: %.2f", parent1.getAvg()), 10, 10);
+  fill(0, 64, 255);
+  text(String.format("Parent2: %.2f", parent2.getAvg()), 740, 10);
+  fill(0);
+  text(String.format("Child1: %.2f", child1.getAvg()), 10, 340);
+  text(String.format("Child2: %.2f", child2.getAvg()), 780, 340);
+
+  println("parent1:", parent1.getAvg());
+  println("parent2:", parent2.getAvg());
+  println("child1 :", child1.getAvg());
+  println("child2 :", child2.getAvg());
+}