| public static BetterFeasibleFitness ( bool oldFeasible, bool newFeasible, double oldFitness, double newFitness ) : bool | ||
| oldFeasible | bool | Feasibility of old candidate solution. |
| newFeasible | bool | Feasibility of new candidate solution. |
| oldFitness | double | Fitness of old candidate solution. |
| newFitness | double | Fitness of new candidate solution. |
| return | bool | |
/// <summary>
/// Compute the fitness measure by passing the
/// given parameters to the wrapped problem, and if
/// candidate solution is an improvement then log
/// the results.
/// </summary>
/// <param name="parameters">Candidate solution.</param>
/// <param name="fitnessLimit">Preemptive Fitness Limit</param>
/// <param name="newFeasible">Feasibility of old candidate solution.</param>
/// <param name="oldFeasible">Feasibility of new candidate solution.</param>
/// <returns>Fitness value.</returns>
public override double Fitness(double[] parameters, double fitnessLimit, bool oldFeasible, bool newFeasible)
{
double fitness = Problem.Fitness(parameters, fitnessLimit, oldFeasible, newFeasible);
// Log solutions. If feasibiilty is required then only log feasible solutions.
if (!OnlyFeasible || newFeasible)
{
// Log solutions with better fitness and feasibility.
if (Tools.BetterFeasibleFitness(oldFeasible, newFeasible, fitnessLimit, fitness))
{
// Ensure log does not exceed desired capacity.
if (Log.Count >= Capacity)
{
// Assume log is sorted in ascending (worsening) order.
// Remove worst from the log.
Log.RemoveAt(Log.Count - 1);
}
Solution candidateSolution = new Solution(parameters, fitness, newFeasible);
// Add new solution to the log.
Log.Add(candidateSolution);
// Sort log according to fitness.
// This could be implemented more efficiently
// but it is not crucial for runtime performance
// so this simple implementation is sufficient.
Log.Sort(new Solution.FitnessComparer());
}
}
return(fitness);
}
/// <summary>
/// Print parameters, fitness and feasibility to Console, and print a marking if
/// fitness was an improvement to fitnessLimit.
/// </summary>
public static void PrintSolution(double[] parameters, double fitness, double fitnessLimit, bool oldFeasible, bool newFeasible, bool formatAsArray)
{
// Convert parameters to a string.
string parametersStr = (formatAsArray) ? (Tools.ArrayToString(parameters)) : (Tools.ArrayToStringRaw(parameters));
Console.WriteLine("{0} \t{1} \t{2} {3}",
parametersStr,
Tools.FormatNumber(fitness),
(newFeasible) ? (1) : (0),
Tools.BetterFeasibleFitness(oldFeasible, newFeasible, fitnessLimit, fitness) ? ("***") : (""));
// Flush stdout, this is useful if piping the output and you wish
// to study the the output before the entire optimization run is complete.
Console.Out.Flush();
}
public int Compare(Solution x, Solution y)
{
int retVal;
if (x.Fitness == y.Fitness && x.Feasible == y.Feasible)
{
retVal = 0;
}
else if (Tools.BetterFeasibleFitness(x.Feasible, y.Feasible, x.Fitness, y.Fitness))
{
retVal = 1;
}
else
{
retVal = -1;
}
return(retVal);
}