public static void Improve(Permutation assignment, DoubleMatrix weights, DoubleMatrix distances, DoubleValue quality, IntValue localIterations, IntValue evaluatedSolutions, bool maximization, int maxIterations, CancellationToken cancellation)
{
double evalSolPerMove = 4.0 / assignment.Length;
for (int i = localIterations.Value; i < maxIterations; i++)
{
Swap2Move bestMove = null;
double bestQuality = 0; // we have to make an improvement, so 0 is the baseline
double evaluations = 0.0;
foreach (Swap2Move move in ExhaustiveSwap2MoveGenerator.Generate(assignment))
{
double moveQuality = QAPSwap2MoveEvaluator.Apply(assignment, move, weights, distances);
evaluations += evalSolPerMove;
if (maximization && moveQuality > bestQuality ||
!maximization && moveQuality < bestQuality)
{
bestQuality = moveQuality;
bestMove = move;
}
}
evaluatedSolutions.Value += (int)Math.Ceiling(evaluations);
if (bestMove == null)
{
break;
}
Swap2Manipulator.Apply(assignment, bestMove.Index1, bestMove.Index2);
quality.Value += bestQuality;
localIterations.Value++;
cancellation.ThrowIfCancellationRequested();
}
}
public static void ImproveFast(Permutation assignment, DoubleMatrix weights, DoubleMatrix distances, DoubleValue quality, IntValue localIterations, IntValue evaluatedSolutions, bool maximization, int maxIterations, CancellationToken cancellation)
{
Swap2Move bestMove = null;
double evaluations = 0.0;
var lastQuality = new double[assignment.Length, assignment.Length];
for (int i = localIterations.Value; i < maxIterations; i++)
{
double bestQuality = 0; // we have to make an improvement, so 0 is the baseline
var lastMove = bestMove;
bestMove = null;
foreach (Swap2Move move in ExhaustiveSwap2MoveGenerator.Generate(assignment))
{
double moveQuality;
if (lastMove == null)
{
moveQuality = QAPSwap2MoveEvaluator.Apply(assignment, move, weights, distances);
evaluations += 4.0 / assignment.Length;
}
else
{
moveQuality = QAPSwap2MoveEvaluator.Apply(assignment, move, lastQuality[move.Index1, move.Index2], weights, distances, lastMove);
if (move.Index1 == lastMove.Index1 || move.Index2 == lastMove.Index1 || move.Index1 == lastMove.Index2 || move.Index2 == lastMove.Index2)
{
evaluations += 4.0 / assignment.Length;
}
else
{
evaluations += 2.0 / (assignment.Length * assignment.Length);
}
}
lastQuality[move.Index1, move.Index2] = moveQuality;
if (maximization && moveQuality > bestQuality ||
!maximization && moveQuality < bestQuality)
{
bestQuality = moveQuality;
bestMove = move;
}
}
if (bestMove == null)
{
break;
}
Swap2Manipulator.Apply(assignment, bestMove.Index1, bestMove.Index2);
quality.Value += bestQuality;
localIterations.Value++;
if (cancellation.IsCancellationRequested)
{
evaluatedSolutions.Value += (int)Math.Round(evaluations);
throw new OperationCanceledException();
}
}
evaluatedSolutions.Value += (int)Math.Round(evaluations);
}
protected QAPSwap2MoveEvaluator(QAPSwap2MoveEvaluator original, Cloner cloner)
: base(original, cloner)
{
}
protected QAPSwap2MoveEvaluator(QAPSwap2MoveEvaluator original, Cloner cloner)
: base(original, cloner) {
}
