/// <summary>
/// Update the time series data.
/// </summary>
/// <param name="eaStats">Evolution algorithm statistics object.</param>
/// <param name="popStats">Population statistics object.</param>
public override void UpdateData(
EvolutionAlgorithmStatistics eaStats,
PopulationStatistics popStats)
{
_ppl.Add(eaStats.Generation, eaStats.EvaluationsPerSec);
RefreshGraph();
}
/// <summary>
/// Determine the complexity regulation mode that the evolution algorithm search should be in given the
/// provided evolution algorithm statistics object, and set the current mode to that mode.
/// </summary>
/// <param name="eaStats">Evolution algorithm statistics.</param>
/// <param name="popStats">Population statistics.</param>
/// <returns>The determined <see cref="ComplexityRegulationMode"/>.</returns>
public ComplexityRegulationMode UpdateMode(
EvolutionAlgorithmStatistics eaStats,
PopulationStatistics popStats)
{
// This is the null strategy, therefore do nothing.
return(ComplexityRegulationMode.Complexifying);
}
public void TestTransitionToSimplifying()
{
var strategy = new AbsoluteComplexityRegulationStrategy(10, 10.0);
var eaStats = new EvolutionAlgorithmStatistics();
var popStats = new PopulationStatistics();
ComplexityRegulationMode mode;
// The strategy should initialise to, and remain in, Complexifying mode
// while mean population complexity is below the threshold.
for (int i = 0; i < 11; i++)
{
eaStats.Generation = i;
popStats.MeanComplexity = i;
popStats.MeanComplexityHistory.Enqueue(i);
mode = strategy.UpdateMode(eaStats, popStats);
Assert.AreEqual(ComplexityRegulationMode.Complexifying, mode);
}
// The strategy should switch to simplifying mode when mean complexity
// rises above the threshold.
eaStats.Generation = 11;
popStats.MeanComplexity = 10.01;
popStats.MeanComplexityHistory.Enqueue(10.01);
mode = strategy.UpdateMode(eaStats, popStats);
Assert.AreEqual(ComplexityRegulationMode.Simplifying, mode);
}
/// <summary>
/// Update the graph data.
/// </summary>
/// <param name="eaStats">Evolution algorithm statistics object.</param>
/// <param name="popStats">Population statistics object.</param>
public virtual void UpdateData(
EvolutionAlgorithmStatistics eaStats,
PopulationStatistics popStats)
{
// Note. This method could be defined as abstract, but that would prevent the Window Forms UI designer from working;
// therefore instead it is defined as virtual with no implementation.
}
private ComplexityRegulationMode DetermineMode_WhileSimplifying(
EvolutionAlgorithmStatistics eaStats,
PopulationStatistics popStats)
{
// Currently simplifying.
// Test if simplification (ongoing reduction in complexity) has stalled.
// We allow simplification to progress for a few generations before testing of it has stalled, this allows
// a lead in time for the effects of simplification to occur.
// In addition we do not switch to complexifying if complexity is above the currently defined ceiling.
if (
((eaStats.Generation - _lastTransitionGeneration) > _minSimplifcationGenerations) &&
(popStats.MeanComplexity < _complexityCeiling) &&
((popStats.MeanComplexityHistory.Mean - _prevMeanMovingAverage) >= 0.0))
{
// Simplification has stalled; switch back to complexification.
_currentMode = ComplexityRegulationMode.Complexifying;
_lastTransitionGeneration = eaStats.Generation;
_prevMeanMovingAverage = 0.0;
}
// else: otherwise remain in simplifying mode.
// Update previous mean moving average complexity value.
_prevMeanMovingAverage = popStats.MeanComplexityHistory.Mean;
// Set a new complexity ceiling, relative to the current population complexity mean.
_complexityCeiling = popStats.MeanComplexity + _relativeComplexityCeiling;
return(_currentMode);
}
/// <summary>
/// Update the time series data.
/// </summary>
/// <param name="eaStats">Evolution algorithm statistics object.</param>
/// <param name="popStats">Population statistics object.</param>
public override void UpdateData(
EvolutionAlgorithmStatistics eaStats,
PopulationStatistics popStats)
{
_bestPpl.Add(eaStats.Generation, popStats.BestComplexity);
_meanPpl.Add(eaStats.Generation, popStats.MeanComplexity);
RefreshGraph();
}
/// <summary>
/// Update the time series data.
/// </summary>
/// <param name="eaStats">Evolution algorithm statistics object.</param>
/// <param name="popStats">Population statistics object.</param>
public override void UpdateData(
EvolutionAlgorithmStatistics eaStats,
PopulationStatistics popStats)
{
_bestPpl.Add(eaStats.Generation, popStats.BestFitness.PrimaryFitness);
_meanPpl.Add(eaStats.Generation, popStats.MeanFitness);
RefreshGraph();
}
/// <summary>
/// Determine the complexity regulation mode that the evolution algorithm search should be in given the
/// provided evolution algorithm statistics object, and set the current mode to that mode.
/// </summary>
/// <param name="eaStats">Evolution algorithm statistics.</param>
/// <param name="popStats">Population statistics.</param>
/// <returns>The determined <see cref="ComplexityRegulationMode"/>.</returns>
public ComplexityRegulationMode UpdateMode(
EvolutionAlgorithmStatistics eaStats,
PopulationStatistics popStats)
{
return(_currentMode switch
{
ComplexityRegulationMode.Complexifying => DetermineMode_WhileComplexifying(eaStats, popStats),
ComplexityRegulationMode.Simplifying => DetermineMode_WhileSimplifying(eaStats, popStats),
_ => throw new InvalidOperationException("Unexpected complexity regulation mode."),
});
public void TestTransitionToComplexifying()
{
var strategy = new RelativeComplexityRegulationStrategy(10, 10.0);
var eaStats = new EvolutionAlgorithmStatistics();
var popStats = new PopulationStatistics();
ComplexityRegulationMode mode;
// Cause an immediate switch to into simplifying mode.
int generation = 0;
eaStats.Generation = generation++;
popStats.MeanComplexity = 11.0;
popStats.MeanComplexityHistory.Enqueue(11.0);
mode = strategy.UpdateMode(eaStats, popStats);
Assert.Equal(ComplexityRegulationMode.Simplifying, mode);
// Reset the buffer that the moving average is calculated from;
// This allows us to change the mean to below the threshold and for the
// moving average to start rising immediately; that would ordinarily cause
// an immediate switch back to complexifying mode, but that is prevented by
// {minSimplifcationGenerations} being set to 10.
popStats.MeanComplexityHistory.Clear();
for (int i = 0; i < 10; i++)
{
eaStats.Generation = generation++;
popStats.MeanComplexity = 2.0;
popStats.MeanComplexityHistory.Enqueue(2.0);
mode = strategy.UpdateMode(eaStats, popStats);
Assert.Equal(ComplexityRegulationMode.Simplifying, mode);
}
// Now that {minSimplifcationGenerations} have passed, the strategy should switch
// back to complexifying mode.
eaStats.Generation = generation++;
popStats.MeanComplexity = 2.0;
popStats.MeanComplexityHistory.Enqueue(2.0);
mode = strategy.UpdateMode(eaStats, popStats);
Assert.Equal(ComplexityRegulationMode.Complexifying, mode);
// The threshold should have been set relative to the popStats.MeanComplexity (to 12).
eaStats.Generation = generation++;
popStats.MeanComplexity = 11.9;
popStats.MeanComplexityHistory.Enqueue(11.9);
mode = strategy.UpdateMode(eaStats, popStats);
Assert.Equal(ComplexityRegulationMode.Complexifying, mode);
eaStats.Generation = generation++;
popStats.MeanComplexity = 12.01;
popStats.MeanComplexityHistory.Enqueue(12.01);
mode = strategy.UpdateMode(eaStats, popStats);
Assert.Equal(ComplexityRegulationMode.Simplifying, mode);
}
/// <summary>
/// Determine the complexity regulation mode that the evolution algorithm search should be in given the
/// provided evolution algorithm statistics object.
/// </summary>
/// <param name="eaStats">Evolution algorithm statistics.</param>
/// <param name="popStats">Population statistics.</param>
public ComplexityRegulationMode UpdateMode(
EvolutionAlgorithmStatistics eaStats,
PopulationStatistics popStats)
{
switch (_currentMode)
{
case ComplexityRegulationMode.Complexifying:
return(DetermineMode_WhileComplexifying(eaStats, popStats));
case ComplexityRegulationMode.Simplifying:
return(DetermineMode_WhileSimplifying(eaStats, popStats));
}
throw new InvalidOperationException("Unexpected complexity regulation mode.");
}
public void TestInitialisation()
{
var strategy = new AbsoluteComplexityRegulationStrategy(10, 10.0);
var eaStats = new EvolutionAlgorithmStatistics();
var popStats = new PopulationStatistics();
// The strategy should initialise to, and remain in, Complexifying mode.
for (int i = 0; i < 100; i++)
{
eaStats.Generation = i;
ComplexityRegulationMode mode = strategy.UpdateMode(eaStats, popStats);
Assert.AreEqual(ComplexityRegulationMode.Complexifying, mode);
}
}
private ComplexityRegulationMode DetermineMode_WhileComplexifying(
EvolutionAlgorithmStatistics eaStats,
PopulationStatistics popStats)
{
// Currently complexifying.
// Test if the complexity ceiling has been reached.
if (popStats.MeanComplexity > _complexityCeiling)
{
// Switch to simplifying mode.
_currentMode = ComplexityRegulationMode.Simplifying;
_lastTransitionGeneration = eaStats.Generation;
_prevMeanMovingAverage = popStats.MeanComplexityHistory.Mean;
}
return(_currentMode);
}
