Changeset 15779

Timestamp:

02/15/18 08:49:41 (7 years ago)

Author:

gkronber

Message:

#2901: implemented a static method for tournament selection

File:

• branches/2901_StaticSelectionMethods/HeuristicLab.Selection/3.3/TournamentSelector.cs (modified) (1 diff)

branches/2901_StaticSelectionMethods/HeuristicLab.Selection/3.3/TournamentSelector.cs

@@ -69 +69 @@
 
       for (int i = 0; i < count; i++) {
-        int best = random.Next(scopes.Count);
-        int index;
-        for (int j = 1; j < groupSize; j++) {
-          index = random.Next(scopes.Count);
-          if (((maximization) && (qualities[index] > qualities[best])) ||
-              ((!maximization) && (qualities[index] < qualities[best]))) {
-            best = index;
-          }
-        }
+        var selectedIdx = SelectIdx(random, qualities, maximization, groupSize);
 
         if (copy)
-          selected[i] = (IScope)scopes[best].Clone();
+          selected[i] = (IScope)scopes[selectedIdx].Clone();
         else {
-          selected[i] = scopes[best];
-          scopes.RemoveAt(best);
-          qualities.RemoveAt(best);
+          selected[i] = scopes[selectedIdx];
+          scopes.RemoveAt(selectedIdx);
+          qualities.RemoveAt(selectedIdx);
         }
       }
       return selected;
     }
+
+    public static int SelectIdx(IRandom random, IList<double> qualities, bool maximization, int groupSize) {
+      int best = random.Next(qualities.Count);
+      int index;
+      for (int j = 1; j < groupSize; j++) {
+        index = random.Next(qualities.Count);
+        if (((maximization) && (qualities[index] > qualities[best])) ||
+            ((!maximization) && (qualities[index] < qualities[best]))) {
+          best = index;
+        }
+      }
+
+      return best;
+    }
   }
 }