public FloatingPointChromosome Execute(FloatingPointChromosome chromosome)
{
if (chromosome == null)
{
throw new ArgumentNullException(nameof(chromosome));
}
FloatingPointChromosome mutant = (FloatingPointChromosome)chromosome.Copy();
IFloatingPointProblem problem = mutant.Problem;
for (int i = 0; i < problem.Dimension; i++)
{
if (_random.NextDouble() <= _mutationProbability)
{
double lowerBound = problem.GetLowerBound(i);
double upperBound = problem.GetUpperBound(i);
double mu = (upperBound - lowerBound) / 2;
double sigma = upperBound - mu;
mu /= 3;
mutant.SetValue(i, Math.Min(Math.Max(_random.NextGaussian(mu, sigma), lowerBound), upperBound));
}
}
return(mutant);
}
public FloatingPointChromosome Execute(FloatingPointChromosome chromosome)
{
if (chromosome == null)
{
throw new ArgumentNullException(nameof(chromosome));
}
FloatingPointChromosome mutant = (FloatingPointChromosome)chromosome.Copy();
if (_random.NextDouble() > _mutationProbability)
{
return(mutant);
}
IFloatingPointProblem problem = chromosome.Problem;
for (int i = 0; i < problem.Dimension; i++)
{
double lowerBound = problem.GetLowerBound(i);
double upperBound = problem.GetUpperBound(i);
double mutantValue = _random.NextDouble(lowerBound, upperBound);
mutant.SetValue(i, mutantValue);
}
return(mutant);
}
public IList <FloatingPointChromosome> Execute(IList <FloatingPointChromosome> parents)
{
if (parents == null)
{
throw new ArgumentNullException(nameof(parents));
}
if (parents.Count != NumberOfParents)
{
throw new ArgumentException($"There must be {NumberOfParents} parents instead of {parents.Count}");
}
FloatingPointChromosome parent1 = (FloatingPointChromosome)parents[0].Copy();
FloatingPointChromosome parent2 = (FloatingPointChromosome)parents[1].Copy();
IList <FloatingPointChromosome> result = new List <FloatingPointChromosome>();
if (_random.NextDouble() > _crossoverProbability)
{
result.Add(parent1);
result.Add(parent2);
return(result);
}
IFloatingPointProblem problem = parent1.Problem;
// Order parents so that the first has the worst Fitness
IList <FloatingPointChromosome> orderedParents = parents.OrderBy(c => c, problem.FitnessComparer).ToList();
parent1 = (FloatingPointChromosome)orderedParents[0].Copy();
parent2 = (FloatingPointChromosome)orderedParents[1].Copy();
FloatingPointChromosome child = parent1;
for (int i = 0; i < parent1.Dimension; i++)
{
double parent1Value = parent1.GetValue(i);
double parent2Value = parent2.GetValue(i);
double a = _random.NextDouble();
var childValue = a * (parent2Value - parent1Value) + parent2Value;
while (childValue < problem.GetLowerBound(i) || childValue > problem.GetUpperBound(i))
{
a = _random.NextDouble();
childValue = a * (parent2Value - parent1Value) + parent2Value;
}
child.SetValue(i, childValue);
}
result.Add(child);
return(result);
}
public FloatingPointChromosome(IFloatingPointProblem problem) : base(problem)
{
_problem = problem;
// Initialize randomly
for (int i = 0; i < Dimension; i++)
{
double lowerBound = _problem.GetLowerBound(i);
double upperBound = _problem.GetUpperBound(i);
SetValue(i, RandomNumberGeneratorProvider.Instance.NextDouble(lowerBound, upperBound));
}
}
public FloatingPointChromosome(FloatingPointChromosome chromosome) : base(chromosome)
{
_problem = chromosome._problem;
}
