private Genome ApplyMutation(Genome genome)
{
for (int gene = 0; gene < _numCoins; gene++)
{
if (rand.NextDouble() < _mutationRate)
{
int numIndicesToSkip = rand.Next(4) + 1; // Avoids using the same index
int startIndex = rand.Next(6);
// Make sure neither of the indices we are swapping are spaces for population not being used.
while (!_coinsUsed[startIndex])
{
startIndex = rand.Next(6);
}
// complicated check ensures that we are checking inside the array
while (!_coinsUsed[(startIndex + numIndicesToSkip) % 6])
{
numIndicesToSkip = rand.Next(4) +1;
}
int amountToSwap = rand.Next(genome[startIndex]);
genome[startIndex] -= amountToSwap;
genome[(numIndicesToSkip + startIndex) % 6] += amountToSwap;
}
}
return genome;
}
public Genome Clone()
{
Genome aGenome = new Genome();
for (int i = 0; i < 6; i++)
aGenome.Set(i, Get(i));
return aGenome;
}
private Genome[] RunGA(Genome[] population)
{
population = OrganizeGeneration(population);
Genome[] nextGen = CreateNextGeneration(population);
nextGen.CopyTo(population, 0);
_genCount++;
population = OrganizeGeneration(population);
DisplayGeneration(population, _genCount);
_solutionFound = SolutionFound(population);
return population;
}
private bool SolutionFound(Genome[] population)
{
foreach (Genome genome in population)
{
if (genome.Fitness(_target) == 0)
return true;
}
return false;
}
private Genome[] OrganizeGeneration(Genome[] population)
{
// Order genes in population by fitness
IEnumerable<Genome> orderedPopulation = population.OrderBy(genome => genome.Fitness(_target));
return orderedPopulation.ToArray<Genome>();
}
private Genome PickAFitParent(Genome[] population)
{
int parentIndex1 = rand.Next(_popSize);
int parentIndex2 = rand.Next(_popSize);
Genome parent;
if (population[parentIndex1].Fitness(_target) < population[parentIndex2].Fitness(_target))
parent = population[parentIndex1];
else
parent = population[parentIndex2];
return parent.Clone();
}
private void DisplayGeneration(Genome[] population, int genCount)
{
textOutput.Clear();
StringBuilder sb = new StringBuilder(100 * _popSize);
foreach (Genome genome in population)
{
int[] current = genome.ToArray();
sb.Append(genome.Fitness(_target).ToString()
+ "\t0.01: " + GetPaddedValue(current[(int)CoinNames.pennies], 2)
+ " 0.05: " + GetPaddedValue(current[(int)CoinNames.nickels], 2)
+ " 0.10: " + GetPaddedValue(current[(int)CoinNames.dimes], 2)
+ " 0.25: " + GetPaddedValue(current[(int)CoinNames.quarters], 2)
+ " 0.50: " + GetPaddedValue(current[(int)CoinNames.halfDollars], 2)
+ " 1.00: " + GetPaddedValue(current[(int)CoinNames.dollars], 2)
+ " Total: " + GetDollarValue(genome).ToString()
+ "\r\n");
}
textOutput.Text = sb.ToString();
this.Text = "Generation #" + genCount;
this.Update();
Thread.Sleep(25);
}
private double GetDollarValue(Genome genome)
{
double dollarValue = 0;
dollarValue +=
+ genome.Get((int)CoinNames.pennies) * ((double)CoinValues.pennies / 100)
+ genome.Get((int)CoinNames.nickels) * ((double)CoinValues.nickels / 100)
+ genome.Get((int)CoinNames.dimes) * ((double)CoinValues.dimes / 100)
+ genome.Get((int)CoinNames.quarters) * ((double)CoinValues.quarters / 100)
+ genome.Get((int)CoinNames.halfDollars) * ((double)CoinValues.halfDollars / 100)
+ genome.Get((int)CoinNames.dollars) * ((double)CoinValues.dollars / 100);
return dollarValue;
}
private Genome[] CreateNextGeneration(Genome[] population)
{
Genome[] nextGen = new Genome[_popSize];
int numGenesToKeep = (int)(_popSize * _elitism);
//for (int i = 0; i < numGenesToKeep; i++)
//{
// nextGen[i] = population[i].ToArray();
//}
//nextGen = population.ToArray();
population.ToArray().CopyTo(nextGen, 0);
for (int i = numGenesToKeep; i < _popSize; i++)
{
Genome copyOfParent = PickAFitParent(population);
Genome child = ApplyMutation(copyOfParent);
nextGen[i] = child;
}
return OrganizeGeneration(nextGen);
}
private Genome[] CreateRandomPopulation(int _popSize, bool[] _coinsUsed)
{
Genome[] population = new Genome[_popSize];
for (int i = 0; i < _popSize; i++)
population[i] = new Genome();
int numCoinsRemaining = _numCoins;
// Get random values which add up to _numCoins
for (int genome = 0; genome < _popSize; genome++)
{
for (int coin = 0; coin < 5; coin++)
{
if (_coinsUsed[coin])
{
population[genome].Set(coin, rand.Next(numCoinsRemaining));
numCoinsRemaining -= population[genome].Get(coin);
}
}
population[genome].Set(5, numCoinsRemaining);
numCoinsRemaining = _numCoins;
}
// Further randomize by changing order of values randomly
foreach (Genome genome in population)
{
genome.Randomize();
for (int i = 0; i < 6; i++)
{
if (!_coinsUsed[i])
{
if (genome.Get(i) != 0)
{
int indexToSwapWith = genome.Find(0);
genome.Swap(i, indexToSwapWith);
}
}
}
}
return population;
}
public static void BoundaryMutation(ref Genome gene, int index, Random rand)
{
gene.Genes[index] = rand.Next(0, 2) > 0 ? Functions.MaxValue : Functions.MinValue;
}
public static void SimpleMutation(ref Genome gene, int index, Random rand)
{
gene.Genes[index] = Functions.NewParamValue(rand);
}
public static void WholeArithmeticRecombination(Genome firstParent, Genome secondParent, ref Genome firstChild, Random rand)
{
firstChild.Fitness = Single.MaxValue;
for (int i = 0; i < firstParent.Genes.Length; i++)
{
firstChild.Genes[i] = Average(firstParent.Genes[i], secondParent.Genes[i]);
}
}
public static void SingleArithmeticRecombination(Genome firstParent, Genome secondParent, ref Genome firstChild, Random rand)
{
int location = rand.Next(0, firstChild.Genes.Length);
firstChild.Copy(firstParent);
firstChild.Fitness = Single.MaxValue;
firstChild.Genes[location] = Average(firstParent.Genes[location], secondParent.Genes[location]);
}
public static void DiscreteRecombination(Genome firstParent, Genome secondParent, ref Genome firstChild, Random rand)
{
firstChild.Fitness = Single.MaxValue;
for (int i = 0; i < firstChild.Genes.Length; i++)
{
firstChild.Genes[i] = rand.NextDouble() > 0.5 ? firstParent.Genes[i] : secondParent.Genes[i];
}
}