public void TestMeasureDistanceThreshold()
{
var distanceMetric = new DistanceMetric();
Assert.That(distanceMetric.MeasureDistance(genotypeA, genotypeB, 0.0f));
Assert.That(!distanceMetric.MeasureDistance(genotypeA, genotypeC, 0.0f));
}
public void TestMeasureDistanceMutation()
{
var distanceMetric = new DistanceMetric(0.0f, 0.0f, 1.0f);
var distanceAB = distanceMetric.MeasureDistance(genotypeA, genotypeB);
Assert.AreEqual(0.0f, distanceAB);
var distanceAC = distanceMetric.MeasureDistance(genotypeA, genotypeC);
Assert.AreEqual(1f / 3f, distanceAC);
}
public void TestMeasureDistanceMutation()
{
var distanceMetric = new DistanceMetric(0.0f, 0.0f, 1.0f);
var distanceAB = distanceMetric.MeasureDistance(genotypeA, genotypeB);
Assert.AreEqual(0.0f, distanceAB);
var distanceAC = distanceMetric.MeasureDistance(genotypeA, genotypeC);
Assert.AreEqual(1f / 3f, distanceAC);
}
public Specie[] Speciate(Specie[] species, Phenotype[] phenotypes)
{
// Begin new species
var speciesListNext = species.Select(sp => {
if (sp.BestAdjustedFitness >= sp.PastBestAdjustedFitness)
{
return(new Specie(sp.SpeciesId, sp.Representative, sp.Age + 1,
sp.Age, sp.BestAdjustedFitness));
}
else
{
return(new Specie(sp.SpeciesId, sp.Representative, sp.Age + 1,
sp.BestAge, sp.PastBestAdjustedFitness));
}
}).ToList();
// Place genotypes
foreach (var phenotype in phenotypes)
{
bool foundSpecies = false;
foreach (var specie in speciesListNext)
{
// Check if the phenotype belong to this species
var distance = distanceMetric.MeasureDistance(phenotype.Genotype, specie.Representative);
if (distance <= distanceThreshold)
{
specie.Add(phenotype);
foundSpecies = true;
break;
}
}
// Create a new species for the phenotype if necessary
if (!foundSpecies)
{
var spNext = new Specie(nextSpeciesId, phenotype.Genotype, 0, 0, 0.0f);
nextSpeciesId++;
spNext.Add(phenotype);
speciesListNext.Add(spNext);
}
}
// Adjust threshold to accomodate the correct number of species
if (speciesListNext.Count < desiredSpeciesCount) // Too few
{
distanceThreshold -= distanceThresholdAdjustment; // Decrease threshold
}
else if (speciesListNext.Count > desiredSpeciesCount) // To many
{
distanceThreshold += distanceThresholdAdjustment; // Increase threshold
}
// Prune empty species
var dead = speciesListNext.Where(sp => sp.Count == 0);
var speciesNext = speciesListNext.Except(dead);
// Adjust each species' phenotypes' fitness
foreach (var specie in speciesNext)
{
foreach (var phenotype in specie)
{
var adjustedFitness = phenotype.Fitness;
var stagnation = specie.Age - specie.BestAge;
if (stagnation >= 10 && stagnation < 100)
{
// age: 10, penalty = 0.9x
// age: 25, penalty = 0.75x
// age: 50, penalty = 0.5x
// age: 75, penalty = 0.25x
// age: 90, penalty = 0.1x
adjustedFitness *= 1.0f - (stagnation / 100.0f); // Up to 100% penalty
}
if (specie.Age < 10)
{
// age: 0, reward = 2x
// age: 2, reward = 1.8x
// age: 5, reward = 1.5x
// age: 8, reward = 1.2x
// age: 10, reward = 1x
adjustedFitness *= 1.0f + (1.0f - (specie.Age / 10.0f)); // Up to 100% bonus
}
adjustedFitness /= (float)specie.Count;
phenotype.AdjustedFitness = Mathf.Max(adjustedFitness, 0.001f);
}
}
return(speciesNext.OrderByDescending(sp => sp.BestAdjustedFitness)
.ToArray());
}
public void TestMeasureDistanceThreshold()
{
var distanceMetric = new DistanceMetric();
Assert.That(distanceMetric.MeasureDistance(genotypeA, genotypeB, 0.0f));
Assert.That(!distanceMetric.MeasureDistance(genotypeA, genotypeC, 0.0f));
}