protected internal override void InitIndividual(GAIndividual inIndividual)
{
PushGPIndividual i = (PushGPIndividual)inIndividual;
int randomCodeSize = Rng.Next(_maxRandomCodeSize) + 2;
Program p = _interpreter.randProgram.RandomCode(randomCodeSize);
i.SetProgram(p);
}
/// <summary>Evaluates the current population and updates their fitness values.</summary>
/// <remarks>
/// Evaluates the current population and updates their fitness values. This
/// method may be overridden by subclasses to customize GA behavior.
/// </remarks>
protected internal virtual void Evaluate()
{
double totalFitness = 0;
_bestMeanFitness = float.MaxValue;
for (int n = 0; n < _populations[_currentPopulation].Length; n++)
{
GAIndividual i = _populations[_currentPopulation][n];
EvaluateIndividual(i);
totalFitness += i.GetFitness();
if (i.GetFitness() < _bestMeanFitness)
{
_bestMeanFitness = i.GetFitness();
_bestIndividual = n;
_bestErrors = i.GetErrors();
}
}
_populationMeanFitness = totalFitness / _populations[_currentPopulation].Length;
}
/// <summary>
/// Sets the population size and resets the GA generation count, as well as
/// initializing the population with random individuals.
/// </summary>
/// <param name="inSize">the size of the new GA population.</param>
/// <exception cref="System.Exception"/>
protected internal virtual void ResizeAndInitialize(int inSize)
{
_populations = new GAIndividual[][] { new GAIndividual[inSize], new GAIndividual[inSize] };
_currentPopulation = 0;
_generationCount = 0;
object iObject = System.Activator.CreateInstance(_individualClass);
if (!(iObject is GAIndividual))
{
throw new Exception("individual-class must inherit from class GAIndividual");
}
GAIndividual individual = (GAIndividual)iObject;
for (int i = 0; i < inSize; i++)
{
_populations[0][i] = individual.Clone();
InitIndividual(_populations[0][i]);
}
}
protected internal override void Evaluate()
{
float totalFitness = 0;
_bestMeanFitness = float.MaxValue;
for (int n = 0; n < _populations[_currentPopulation].Length; n++)
{
GAIndividual i = _populations[_currentPopulation][n];
EvaluateIndividual(i);
totalFitness += i.GetFitness();
// fitness is minimized.
if (i.GetFitness() < _bestMeanFitness)
{
_bestMeanFitness = i.GetFitness();
_bestIndividual = n;
_bestSize = ((PushGPIndividual)i)._program.ProgramSize();
_bestErrors = i.GetErrors();
}
}
_populationMeanFitness = totalFitness / _populations[_currentPopulation].Length;
}
protected internal virtual void EvaluateIndividual(GAIndividual inIndividual, bool duringSimplify)
{
List <float> errors = new List <float>();
if (!duringSimplify)
{
_averageSize += ((PushGPIndividual)inIndividual)._program.ProgramSize();
}
var sw = Stopwatch.StartNew();
for (int n = 0; n < _testCases.Count; n++)
{
GATestCase test = _testCases[n];
float e = EvaluateTestCase(inIndividual, test._input, test._output);
errors.Add(e);
}
// XXX We measure the time but don't do anything with it.
var t = sw.ElapsedMilliseconds;
sw.Stop();
inIndividual.SetFitness(AbsoluteAverageOfErrors(errors));
inIndividual.SetErrors(errors);
}
protected internal override void EvaluateIndividual(GAIndividual inIndividual)
{
EvaluateIndividual(inIndividual, false);
}
public abstract float EvaluateTestCase(GAIndividual inIndividual, object inInput, object inOutput);
protected internal abstract void EvaluateIndividual(GAIndividual inIndividual);
protected internal abstract void InitIndividual(GAIndividual inIndividual);
