public static void Improve(IRandom random, Permutation assignment, DoubleMatrix weights, DoubleMatrix distances, DoubleValue quality, IntValue localIterations, IntValue evaluatedSolutions, bool maximization, int maxIterations, int neighborhoodSize, CancellationToken cancellation)
{
for (int i = localIterations.Value; i < maxIterations; i++)
{
ScrambleMove bestMove = null;
double bestQuality = 0; // we have to make an improvement, so 0 is the baseline
double evaluations = 0.0;
for (int j = 0; j < neighborhoodSize; j++)
{
var move = StochasticScrambleMultiMoveGenerator.GenerateRandomMove(assignment, random);
double moveQuality = QAPScrambleMoveEvaluator.Apply(assignment, move, weights, distances);
evaluations += 2.0 * move.ScrambledIndices.Length / assignment.Length;
if (maximization && moveQuality > bestQuality ||
!maximization && moveQuality < bestQuality)
{
bestQuality = moveQuality;
bestMove = move;
}
}
evaluatedSolutions.Value += (int)Math.Ceiling(evaluations);
if (bestMove == null)
{
break;
}
ScrambleManipulator.Apply(assignment, bestMove.StartIndex, bestMove.ScrambledIndices);
quality.Value += bestQuality;
localIterations.Value++;
cancellation.ThrowIfCancellationRequested();
}
}
protected QAPScrambleMoveEvaluator(QAPScrambleMoveEvaluator original, Cloner cloner)
: base(original, cloner) {
}
protected QAPScrambleMoveEvaluator(QAPScrambleMoveEvaluator original, Cloner cloner)
: base(original, cloner)
{
}