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 permutation, TwoPointFiveMove move, Func <int, int, double> distance, DoubleArray probabilities)
{
if (move.IsInvert)
{
return(PTSPAnalyticalInversionMoveEvaluator.EvaluateMove(permutation,
new InversionMove(move.Index1, move.Index2, move.Permutation), distance, probabilities));
}
else
{
return(PTSPAnalyticalInsertionMoveEvaluator.EvaluateMove(permutation,
new TranslocationMove(move.Index1, move.Index1, move.Index2), distance, probabilities));
}
}