Changeset 15572 for branches/GeneralizedQAP/HeuristicLab.Problems.GeneralizedQuadraticAssignment/3.3/Moves/StochasticNMoveSingleMoveGenerator.cs

Timestamp:

01/03/18 00:28:51 (6 years ago)

Author:

abeham

Message:

#1614:

• fixed a bug in GRASP where solutions in the elite set would be mutated
• introduced termination criteria when reaching best-known quality
• tweaked generating random numbers in StochasticNMoveSingleMoveGenerator
• changed DiscreteLocationCrossover to use an allele from one of the parents instead of introducing a mutation in case no feasible insert location is found
• changed OSGA maxselpress to 500
• slight change to contexts, introduced single-objectiveness much earlier in the class hierachy
  • limited ContextAlgorithm to SingleObjectiveBasicProblems (doesn't matter here)

File:

• branches/GeneralizedQAP/HeuristicLab.Problems.GeneralizedQuadraticAssignment/3.3/Moves/StochasticNMoveSingleMoveGenerator.cs (modified) (3 diffs)

branches/GeneralizedQAP/HeuristicLab.Problems.GeneralizedQuadraticAssignment/3.3/Moves/StochasticNMoveSingleMoveGenerator.cs

@@ -65 +65 @@
 
       var reassignment = new int[dim];
-      reassignment[equip] = ReassignEquipment(random, equip, assignment[equip], locations);
+      reassignment[equip] = 1 + (assignment[equip] + random.Next(1, locations)) % locations;
 
       return new NMove(reassignment, equipments);
@@ -74 +74 @@
       if (locations <= 1) throw new ArgumentException("There must be at least two locations.");
       var dim = assignment.Length;
-      var equipments = new List<int>(2) { random.Next(dim), -1 };
-      do {
-        equipments[1] = random.Next(dim);
-      } while (equipments[0] == equipments[1]);
+      var equipments = new List<int>(2) { random.Next(dim) };
+      equipments.Add((equipments[0] + random.Next(1, dim)) % dim);
 
       var reassignment = new int[dim];
       for (var i = 0; i < 2; i++) {
         var equip = equipments[i];
-        reassignment[equip] = ReassignEquipment(random, equip, assignment[equip], locations);
+        reassignment[equip] = 1 + (assignment[equip] + random.Next(1, locations)) % locations;
       }
       return new NMove(reassignment, equipments);
@@ -98 +96 @@
       for (var i = 0; i < n; i++) {
         var equip = equipments[i];
-        reassignment[equip] = ReassignEquipment(random, equip, assignment[equip], locations);
+        reassignment[equip] = 1 + (assignment[equip] + random.Next(1, locations)) % locations;
       }
       return new NMove(reassignment, equipments);
-    }
-
-    private static int ReassignEquipment(IRandom random, int equip, int prevLocation, int locations) {
-      var newLoc = random.Next(locations) + 1;
-      while (newLoc == prevLocation + 1)
-        newLoc = random.Next(locations) + 1;
-      return newLoc;
     }