Changeset 6960 for branches/VRP/HeuristicLab.Problems.VehicleRouting/3.4/Encodings/Potvin/PotvinEncoding.cs

Timestamp:

11/08/11 09:47:31 (12 years ago)

Author:

svonolfe

Message:

Added pairwise manipulators, removed relocation manipulator (#1177)

File:

• branches/VRP/HeuristicLab.Problems.VehicleRouting/3.4/Encodings/Potvin/PotvinEncoding.cs (modified) (1 diff)

branches/VRP/HeuristicLab.Problems.VehicleRouting/3.4/Encodings/Potvin/PotvinEncoding.cs

@@ -165 +165 @@
     }
 
+    public void InsertPair(Tour tour, int source, int target, IVRPProblemInstance problemInstance, int positionToAvoid = -1, int positionToAvoid2 = -1) {
+      int stops = tour.Stops.Count;
+      VRPEvaluation eval = problemInstance.EvaluateTour(tour, this);
+      double minCosts = double.MaxValue;
+      int sourceLocation = -1;
+      int targetLocation = -1;
+
+      for (int i = 0; i <= stops; i++) {
+        tour.Stops.Insert(i, source);
+        VRPEvaluation tourEval = problemInstance.EvaluateTour(tour, this);
+        double sourceCosts = tourEval.Quality - eval.Quality;
+
+        for (int j = i + 1; j <= stops + 1; j++) {
+          if (positionToAvoid != i || positionToAvoid2 != j || stops == 0) {
+            bool feasible;
+            double targetCosts = problemInstance.GetInsertionCosts(tourEval, this, target, 0, j, out feasible);
+
+            double costs = sourceCosts + targetCosts;
+            if (costs < minCosts) {
+              minCosts = costs;
+              sourceLocation = i;
+              targetLocation = j;
+            }
+          }
+        }
+        tour.Stops.Remove(source);
+      }
+
+      tour.Stops.Insert(sourceLocation, source);
+      tour.Stops.Insert(targetLocation, target);
+    }
+
     public bool FindInsertionPlace(int city, int routeToAvoid, bool allowInfeasible, out int route, out int place) {
       route = -1;