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 override IOperation InstrumentedApply()
{
IOperation next = base.InstrumentedApply();
IVRPEncoding solution = VRPToursParameter.ActualValue;
generator.PermutationParameter.ActualName = VRPToursParameter.ActualName;
IAtomicOperation op = this.ExecutionContext.CreateChildOperation(generator);
op.Operator.Execute((IExecutionContext)op, CancellationToken);
foreach (IScope scope in this.ExecutionContext.Scope.SubScopes)
{
IVariable moveVariable = scope.Variables[
TranslocationMoveParameter.ActualName];
if (moveVariable.Value is TranslocationMove &&
!(moveVariable.Value is AlbaTranslocationMove))
{
TranslocationMove move = moveVariable.Value as TranslocationMove;
moveVariable.Value =
new AlbaTranslocationMove(
move.Index1, move.Index2, move.Index3, solution as AlbaEncoding);
}
}
return(next);
}
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 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));
}
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);
}
protected override void PerformMove()
{
IVariable moveVariable = this.ExecutionContext.Scope.Variables[
TranslocationMoveParameter.ActualName];
TranslocationMove move = moveVariable.Value as TranslocationMove;
VRPToursParameter.ActualValue = move.Permutation as AlbaEncoding;
moveMaker.PermutationParameter.ActualName = VRPToursParameter.ActualName;
IAtomicOperation op = this.ExecutionContext.CreateChildOperation(moveMaker);
op.Operator.Execute((IExecutionContext)op, CancellationToken);
}
public static double Apply(Permutation assignment, TranslocationMove move, DoubleMatrix weights, DoubleMatrix distances)
{
double moveQuality = 0;
int min = Math.Min(move.Index1, move.Index3);
int max = Math.Max(move.Index2, move.Index3 + (move.Index2 - move.Index1));
int iOffset, changeOffset;
if (move.Index1 < move.Index3)
{
iOffset = move.Index2 - move.Index1 + 1;
changeOffset = min + max - move.Index2;
}
else
{
iOffset = move.Index1 - move.Index3;
changeOffset = min + move.Index2 - move.Index1 + 1;
}
for (int i = min; i <= max; i++)
{
if (i == changeOffset)
{
iOffset -= (max - min + 1);
}
int jOffset = ((move.Index1 < move.Index3) ? (move.Index2 - move.Index1 + 1) : (move.Index1 - move.Index3));
for (int j = 0; j < assignment.Length; j++)
{
moveQuality -= weights[i, j] * distances[assignment[i], assignment[j]];
if (j < min || j > max)
{
moveQuality -= weights[j, i] * distances[assignment[j], assignment[i]];
moveQuality += weights[i, j] * distances[assignment[i + iOffset], assignment[j]];
moveQuality += weights[j, i] * distances[assignment[j], assignment[i + iOffset]];
}
else
{
if (j == changeOffset)
{
jOffset -= (max - min + 1);
}
moveQuality += weights[i, j] * distances[assignment[i + iOffset], assignment[j + jOffset]];
}
}
}
return(moveQuality);
}
public override IOperation Apply()
{
TranslocationMove move = TranslocationMoveParameter.ActualValue;
if (move == null)
{
throw new InvalidOperationException("Translocation move is not found.");
}
Permutation assignment = PermutationParameter.ActualValue;
DoubleMatrix distances = DistancesParameter.ActualValue;
DoubleMatrix weights = WeightsParameter.ActualValue;
double moveQuality = QualityParameter.ActualValue.Value;
moveQuality += Apply(assignment, move, weights, distances);
MoveQualityParameter.ActualValue = new DoubleValue(moveQuality);
return(base.Apply());
}
public static double EvaluateByCoordinates(Permutation permutation, TranslocationMove move, DoubleMatrix coordinates, TSPTranslocationMovePathEvaluator evaluator)
{
if (move.Index1 == move.Index3 ||
move.Index2 == permutation.Length - 1 && move.Index3 == 0 ||
move.Index1 == 0 && move.Index3 == permutation.Length - 1 - move.Index2)
{
return(0);
}
int edge1source = permutation.GetCircular(move.Index1 - 1);
int edge1target = permutation[move.Index1];
int edge2source = permutation[move.Index2];
int edge2target = permutation.GetCircular(move.Index2 + 1);
int edge3source, edge3target;
if (move.Index3 > move.Index1)
{
edge3source = permutation.GetCircular(move.Index3 + move.Index2 - move.Index1);
edge3target = permutation.GetCircular(move.Index3 + move.Index2 - move.Index1 + 1);
}
else
{
edge3source = permutation.GetCircular(move.Index3 - 1);
edge3target = permutation[move.Index3];
}
double moveQuality = 0;
// remove three edges
moveQuality -= evaluator.CalculateDistance(coordinates[edge1source, 0], coordinates[edge1source, 1],
coordinates[edge1target, 0], coordinates[edge1target, 1]);
moveQuality -= evaluator.CalculateDistance(coordinates[edge2source, 0], coordinates[edge2source, 1],
coordinates[edge2target, 0], coordinates[edge2target, 1]);
moveQuality -= evaluator.CalculateDistance(coordinates[edge3source, 0], coordinates[edge3source, 1],
coordinates[edge3target, 0], coordinates[edge3target, 1]);
// add three edges
moveQuality += evaluator.CalculateDistance(coordinates[edge3source, 0], coordinates[edge3source, 1],
coordinates[edge1target, 0], coordinates[edge1target, 1]);
moveQuality += evaluator.CalculateDistance(coordinates[edge2source, 0], coordinates[edge2source, 1],
coordinates[edge3target, 0], coordinates[edge3target, 1]);
moveQuality += evaluator.CalculateDistance(coordinates[edge1source, 0], coordinates[edge1source, 1],
coordinates[edge2target, 0], coordinates[edge2target, 1]);
return(moveQuality);
}
public static double EvaluateByDistanceMatrix(Permutation permutation, TranslocationMove move, DistanceMatrix distanceMatrix)
{
if (move.Index1 == move.Index3 ||
move.Index2 == permutation.Length - 1 && move.Index3 == 0 ||
move.Index1 == 0 && move.Index3 == permutation.Length - 1 - move.Index2)
{
return(0);
}
int edge1source = permutation.GetCircular(move.Index1 - 1);
int edge1target = permutation[move.Index1];
int edge2source = permutation[move.Index2];
int edge2target = permutation.GetCircular(move.Index2 + 1);
int edge3source, edge3target;
if (move.Index3 > move.Index1)
{
edge3source = permutation.GetCircular(move.Index3 + move.Index2 - move.Index1);
edge3target = permutation.GetCircular(move.Index3 + move.Index2 - move.Index1 + 1);
}
else
{
edge3source = permutation.GetCircular(move.Index3 - 1);
edge3target = permutation[move.Index3];
}
double moveQuality = 0;
// remove three edges
moveQuality -= distanceMatrix[edge1source, edge1target];
moveQuality -= distanceMatrix[edge2source, edge2target];
moveQuality -= distanceMatrix[edge3source, edge3target];
// add three edges
moveQuality += distanceMatrix[edge3source, edge1target];
moveQuality += distanceMatrix[edge2source, edge3target];
moveQuality += distanceMatrix[edge1source, edge2target];
return(moveQuality);
}
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);
}
