public static void Improve(Permutation assignment, DoubleMatrix weights, DoubleMatrix distances, DoubleValue quality, IntValue localIterations, IntValue evaluatedSolutions, bool maximization, int maxIterations, CancellationToken cancellation)
{
for (int i = localIterations.Value; i < maxIterations; i++)
{
TranslocationMove bestMove = null;
double bestQuality = 0; // we have to make an improvement, so 0 is the baseline
double evaluations = 0.0;
foreach (var move in ExhaustiveInsertionMoveGenerator.Generate(assignment))
{
double moveQuality = QAPTranslocationMoveEvaluator.Apply(assignment, move, weights, distances);
int min = Math.Min(move.Index1, move.Index3);
int max = Math.Max(move.Index2, move.Index3 + (move.Index2 - move.Index1));
evaluations += 2.0 * (max - min + 1) / assignment.Length
+ 4.0 * (assignment.Length - (max - min + 1)) / assignment.Length;
if (maximization && moveQuality > bestQuality ||
!maximization && moveQuality < bestQuality)
{
bestQuality = moveQuality;
bestMove = move;
}
}
evaluatedSolutions.Value += (int)Math.Ceiling(evaluations);
if (bestMove == null)
{
break;
}
TranslocationManipulator.Apply(assignment, bestMove.Index1, bestMove.Index2, bestMove.Index3);
quality.Value += bestQuality;
localIterations.Value++;
cancellation.ThrowIfCancellationRequested();
}
}
public static void Improve(Permutation assignment, DoubleMatrix distances, DoubleValue quality, IntValue localIterations, IntValue evaluatedSolutions, bool maximization, int maxIterations, DoubleArray probabilities, CancellationToken cancellation)
{
var distanceM = (DistanceMatrix)distances;
Func <int, int, double> distance = (a, b) => distanceM[a, b];
for (var i = localIterations.Value; i < maxIterations; i++)
{
TranslocationMove bestMove = null;
var bestQuality = quality.Value; // we have to make an improvement, so current quality is the baseline
var evaluations = 0.0;
foreach (var move in ExhaustiveInsertionMoveGenerator.Generate(assignment))
{
var moveQuality = PTSPAnalyticalInsertionMoveEvaluator.EvaluateMove(assignment, move, distance, probabilities);
evaluations++;
if (maximization && moveQuality > bestQuality ||
!maximization && moveQuality < bestQuality)
{
bestQuality = moveQuality;
bestMove = move;
}
}
evaluatedSolutions.Value += (int)Math.Ceiling(evaluations);
if (bestMove == null)
{
break;
}
TranslocationManipulator.Apply(assignment, bestMove.Index1, bestMove.Index2, bestMove.Index3);
quality.Value = bestQuality;
localIterations.Value++;
cancellation.ThrowIfCancellationRequested();
}
}
public void TranslocationMoveEvaluatorTest()
{
var evaluator = new TSPRoundedEuclideanPathEvaluator();
var moveEvaluator = new TSPTranslocationMoveRoundedEuclideanPathEvaluator();
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 = StochasticTranslocationSingleMoveGenerator.Apply(tour, random);
double moveMatrix = TSPTranslocationMovePathEvaluator.EvaluateByDistanceMatrix(tour, move, distances);
double moveCoordinates = TSPTranslocationMovePathEvaluator.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(@"Translocation move is calculated with quality {0}, but actual difference is {5}.
The move would move the segment between {1} and {2} in the tour {3} to the new index {4}.", moveMatrix.ToString(), tour[move.Index1].ToString(), tour[move.Index2].ToString(), tour.ToString(), move.Index3.ToString(), "{0}");
TranslocationManipulator.Apply(tour, move.Index1, move.Index2, move.Index3);
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 static double EvaluateMove(Permutation tour, TranslocationMove move, Func <int, int, double> distance, DoubleArray probabilities)
{
var afterMove = (Permutation)tour.Clone();
TranslocationManipulator.Apply(afterMove, move.Index1, move.Index1, move.Index3);
return(AnalyticalProbabilisticTravelingSalesmanProblem.Evaluate(afterMove, distance, probabilities));
}
public override double EvaluateMove(Permutation permutation, TranslocationMove move, PackingShape binShape,
ReadOnlyItemList <PackingItem> items)
{
// uses full evaluation
TranslocationManipulator.Apply(permutation, move.Index1, move.Index2, move.Index3);
var solution = DecoderParameter.ActualValue.Decode(permutation, binShape, items);
return(SolutionEvaluatorParameter.ActualValue.Evaluate(solution));
}
protected override void EvaluateMove()
{
TranslocationMove move = TranslocationMoveParameter.ActualValue;
//perform move
AlbaEncoding newSolution = move.Permutation.Clone() as AlbaEncoding;
TranslocationManipulator.Apply(newSolution, move.Index1, move.Index2, move.Index3);
UpdateEvaluation(newSolution);
}
public static void Apply(Permutation permutation, TwoPointFiveMove move)
{
if (move.IsInvert)
{
InversionManipulator.Apply(permutation, move.Index1, move.Index2);
}
else
{
TranslocationManipulator.Apply(permutation, move.Index1, move.Index1, move.Index2);
}
}
public void TranslocationManipulatorApplyTest()
{
TestRandom random = new TestRandom();
Permutation parent, expected;
// The following test is based on an example from Larranaga, P. et al. 1999. Genetic Algorithms for the Travelling Salesman Problem: A Review of Representations and Operators. Artificial Intelligence Review, 13, p. 24
random.Reset();
random.IntNumbers = new int[] { 2, 4, 4 };
parent = new Permutation(PermutationTypes.RelativeUndirected, new int[] { 0, 1, 2, 3, 4, 5, 6, 7 });
Assert.IsTrue(parent.Validate());
expected = new Permutation(PermutationTypes.RelativeUndirected, new int[] { 0, 1, 5, 6, 2, 3, 4, 7 });
Assert.IsTrue(expected.Validate());
TranslocationManipulator.Apply(random, parent);
Assert.IsTrue(parent.Validate());
Assert.IsTrue(Auxiliary.PermutationIsEqualByPosition(expected, parent));
}
public void TranslocationMoveEvaluatorTest()
{
for (int i = 0; i < 500; i++)
{
int index1 = random.Next(assignment.Length - 1);
int index2 = random.Next(index1 + 1, assignment.Length);
int insertPointLimit = assignment.Length - index2 + index1 - 1; // get insertion point in remaining part
int insertPoint;
if (insertPointLimit > 0)
{
insertPoint = random.Next(insertPointLimit);
}
else
{
insertPoint = 0;
}
// SYMMETRIC MATRICES
double before = QAPEvaluator.Apply(assignment, symmetricWeights, symmetricDistances);
Permutation clone = new Cloner().Clone(assignment);
TranslocationManipulator.Apply(assignment, index1, index2, insertPoint);
double after = QAPEvaluator.Apply(assignment, symmetricWeights, symmetricDistances);
double move = QAPTranslocationMoveEvaluator.Apply(clone, new TranslocationMove(index1, index2, insertPoint, assignment), symmetricWeights, symmetricDistances);
Assert.IsTrue(move.IsAlmost(after - before), "Failed on symmetric matrices");
// ASYMMETRIC MATRICES
before = QAPEvaluator.Apply(assignment, asymmetricWeights, asymmetricDistances);
clone = new Cloner().Clone(assignment);
TranslocationManipulator.Apply(assignment, index1, index2, insertPoint);
after = QAPEvaluator.Apply(assignment, asymmetricWeights, asymmetricDistances);
move = QAPTranslocationMoveEvaluator.Apply(clone, new TranslocationMove(index1, index2, insertPoint, assignment), asymmetricWeights, asymmetricDistances);
Assert.IsTrue(move.IsAlmost(after - before), "Failed on asymmetric matrices");
// NON-ZERO DIAGONAL ASYMMETRIC MATRICES
before = QAPEvaluator.Apply(assignment, nonZeroDiagonalWeights, nonZeroDiagonalDistances);
clone = new Cloner().Clone(assignment);
TranslocationManipulator.Apply(assignment, index1, index2, insertPoint);
after = QAPEvaluator.Apply(assignment, nonZeroDiagonalWeights, nonZeroDiagonalDistances);
move = QAPTranslocationMoveEvaluator.Apply(clone, new TranslocationMove(index1, index2, insertPoint, assignment), nonZeroDiagonalWeights, nonZeroDiagonalDistances);
Assert.IsTrue(move.IsAlmost(after - before), "Failed on non-zero diagonal matrices");
}
}
public void InsertionMoveEvaluatorTest()
{
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 = StochasticTranslocationSingleMoveGenerator.Apply(tour, random);
var moveMatrix = PTSPEstimatedInsertionMoveEvaluator.EvaluateMove(tour, move, distance, realizations);
TranslocationManipulator.Apply(tour, move.Index1, move.Index1, move.Index3);
var afterMatrix = EstimatedProbabilisticTravelingSalesmanProblem.Evaluate(tour, distance, realizations, out variance);
Assert.IsTrue(Math.Abs(moveMatrix).IsAlmost(Math.Abs(afterMatrix - beforeMatrix)),
string.Format(@"Insertion 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;
}
}
public static double EvaluateMove(Permutation tour, TranslocationMove move, Func <int, int, double> distance, ItemList <BoolArray> realizations)
{
var afterMove = (Permutation)tour.Clone();
TranslocationManipulator.Apply(afterMove, move.Index1, move.Index1, move.Index3);
double moveQuality = 0;
var edges = new int[12];
var indices = new int[12];
edges[0] = tour.GetCircular(move.Index1 - 1);
indices[0] = DecreaseCircularIndex(tour.Length, move.Index1);
edges[1] = tour[move.Index1];
indices[1] = move.Index1;
edges[2] = tour[move.Index1];
indices[2] = move.Index1;
edges[3] = tour.GetCircular(move.Index1 + 1);
indices[3] = IncreaseCircularIndex(tour.Length, move.Index1);
edges[6] = afterMove.GetCircular(move.Index3 - 1);
indices[6] = DecreaseCircularIndex(afterMove.Length, move.Index3);
edges[7] = afterMove[move.Index3];
indices[7] = move.Index3;
edges[8] = afterMove[move.Index3];
indices[8] = move.Index3;
edges[9] = afterMove.GetCircular(move.Index3 + 1);
indices[9] = IncreaseCircularIndex(afterMove.Length, move.Index3);
if (move.Index3 > move.Index1)
{
edges[4] = tour[move.Index3];
indices[4] = move.Index3;
edges[5] = tour.GetCircular(move.Index3 + 1);
indices[5] = indices[9];
edges[10] = afterMove.GetCircular(move.Index1 - 1);
indices[10] = indices[0];
edges[11] = afterMove[move.Index1];
indices[11] = move.Index1;
}
else
{
edges[4] = tour.GetCircular(move.Index3 - 1);
indices[4] = indices[6];
edges[5] = tour[move.Index3];
indices[5] = move.Index3;
edges[10] = afterMove[move.Index1];
indices[10] = move.Index1;
edges[11] = afterMove.GetCircular(move.Index1 + 1);
indices[11] = indices[3];
}
int[] aPosteriori = new int[12];
foreach (var realization in realizations)
{
for (int i = 0; i < edges.Length; i++)
{
Permutation tempPermutation;
if (i < 6)
{
tempPermutation = tour;
}
else
{
tempPermutation = afterMove;
}
if (realization[edges[i]])
{
aPosteriori[i] = edges[i];
}
else
{
int j = 1;
if (i % 2 == 0)
{
// find nearest predecessor in realization if source edge
while (!realization[tempPermutation.GetCircular(indices[i] - j)])
{
j++;
}
aPosteriori[i] = tempPermutation.GetCircular(indices[i] - j);
}
else
{
// find nearest successor in realization if target edge
while (!realization[tempPermutation.GetCircular(indices[i] + j)])
{
j++;
}
aPosteriori[i] = tempPermutation.GetCircular(indices[i] + j);
}
}
}
if (!(aPosteriori[0] == aPosteriori[2] && aPosteriori[1] == aPosteriori[3]) &&
!(aPosteriori[0] == aPosteriori[4] && aPosteriori[1] == aPosteriori[5]) &&
!(aPosteriori[2] == aPosteriori[4] && aPosteriori[3] == aPosteriori[5]))
{
// compute cost difference between the two a posteriori solutions
moveQuality = moveQuality + distance(aPosteriori[6], aPosteriori[7]) + distance(aPosteriori[8], aPosteriori[9]) + distance(aPosteriori[10], aPosteriori[11]);
moveQuality = moveQuality - distance(aPosteriori[0], aPosteriori[1]) - distance(aPosteriori[2], aPosteriori[3]) - distance(aPosteriori[4], aPosteriori[5]);
}
Array.Clear(aPosteriori, 0, aPosteriori.Length);
}
// return average of cost differences
return(moveQuality / realizations.Count);
}