public override IOperation Apply()
{
var solution = CurrentScope.Variables[SolutionParameter.ActualName].Value as Permutation;
if (solution == null)
{
throw new ArgumentException("Cannot improve solution because it has the wrong type.");
}
if (solution.PermutationType != PermutationTypes.RelativeUndirected)
{
throw new ArgumentException("Cannot improve solution because the permutation type is not supported.");
}
for (int i = 0; i < ImprovementAttempts.Value; i++)
{
var move = StochasticInversionSingleMoveGenerator.Apply(solution, Random);
double moveQualtiy = TSPInversionMovePathEvaluator.EvaluateByDistanceMatrix(solution, move, DistanceMatrix);
if (moveQualtiy < 0)
{
InversionManipulator.Apply(solution, move.Index1, move.Index2);
}
}
CurrentScope.Variables.Add(new Variable("LocalEvaluatedSolutions", ImprovementAttempts));
return(base.Apply());
}
public void InversionMoveEvaluatorTest()
{
var evaluator = new TSPRoundedEuclideanPathEvaluator();
var moveEvaluator = new TSPInversionMoveRoundedEuclideanPathEvaluator();
double beforeMatrix = TSPDistanceMatrixEvaluator.Apply(distances, tour);
double beforeCoordinates = TSPCoordinatesPathEvaluator.Apply(evaluator, coordinates, tour);
Assert.IsTrue(beforeMatrix.IsAlmost(beforeCoordinates), "Evaluation differs between using the coordinates and using the distance matrix.");
for (int i = 0; i < 500; i++)
{
var move = StochasticInversionSingleMoveGenerator.Apply(tour, random);
double moveMatrix = TSPInversionMovePathEvaluator.EvaluateByDistanceMatrix(tour, move, distances);
double moveCoordinates = TSPInversionMovePathEvaluator.EvaluateByCoordinates(tour, move, coordinates, moveEvaluator);
Assert.IsTrue(moveMatrix.IsAlmost(moveCoordinates), "Evaluation differs between using the coordinates and using the distance matrix.");
string failureString = string.Format(@"Inversion move is calculated with quality {0}, but actual difference is {4}.
The move would invert the tour {1} between values {2} and {3}.", moveMatrix.ToString(), tour.ToString(), tour[move.Index1].ToString(), tour[move.Index2].ToString(), "{0}");
InversionManipulator.Apply(tour, move.Index1, move.Index2);
double afterMatrix = TSPDistanceMatrixEvaluator.Apply(distances, tour);
double afterCoordinates = TSPCoordinatesPathEvaluator.Apply(evaluator, coordinates, tour);
Assert.IsTrue(afterMatrix.IsAlmost(afterCoordinates), "Evaluation differs between using the coordinates and using the distance matrix.");
Assert.IsTrue(moveMatrix.IsAlmost(afterMatrix - beforeMatrix), string.Format(failureString, (afterMatrix - beforeMatrix).ToString()));
beforeMatrix = afterMatrix;
beforeCoordinates = afterCoordinates;
}
}
public void InversionMoveEvaluatorTest()
{
Func <int, int, double> distance = (a, b) => distances[a, b];
double variance;
var beforeMatrix = EstimatedProbabilisticTravelingSalesmanProblem.Evaluate(tour, distance, realizations, out variance);
for (var i = 0; i < 500; i++)
{
var move = StochasticInversionSingleMoveGenerator.Apply(tour, random);
var moveMatrix = PTSPEstimatedInversionMoveEvaluator.EvaluateMove(tour, move, distance, realizations);
InversionManipulator.Apply(tour, move.Index1, move.Index2);
var afterMatrix = EstimatedProbabilisticTravelingSalesmanProblem.Evaluate(tour, distance, realizations, out variance);
Assert.IsTrue(Math.Abs(moveMatrix).IsAlmost(Math.Abs(afterMatrix - beforeMatrix)),
string.Format(@"Inversion move is calculated with quality {0}, but actual difference is {4}.
The move would invert the tour {1} between values {2} and {3}.",
moveMatrix, tour, tour[move.Index1], tour[move.Index2], Math.Abs(afterMatrix - beforeMatrix)));
beforeMatrix = afterMatrix;
}
}
