private static IWeightMutationStrategy <double> CreateCardinalUniformResetStrategy(
int selectCount, double weightScale, IRandomSourceBuilder rngBuilder)
{
var selectStrategy = new CardinalSubsetSelectionStrategy(selectCount, rngBuilder.Create());
return(ResetWeightMutationStrategy <double> .CreateUniformResetStrategy(selectStrategy, weightScale, rngBuilder.Create()));
}
private static IWeightMutationStrategy <double> CreateCardinalGaussianDeltaStrategy(
int selectCount, double stdDev, IRandomSourceBuilder rngBuilder)
{
var selectStrategy = new CardinalSubsetSelectionStrategy(selectCount, rngBuilder.Create());
return(DeltaWeightMutationStrategy.CreateGaussianDeltaStrategy(selectStrategy, stdDev, rngBuilder.Create()));
}
/// <summary>
/// Create the default connection weight scheme.
/// </summary>
/// <remarks>
/// The scheme currently in use is taken from SharpNEAT version 2.x, i.e. this is the long standing default scheme
/// in sharpneat. There has been little to no exploration of what schemes are good and whether this scheme in particular
/// is good, as such this is a candidate for future research and improvements.
///
/// At time of writing it was thought wise to adopt the scheme from SharpNEAT 2.x because the code base is being
/// rewritten/refactored and it is therefore useful to keep schemes such as this as close to the previous version as
/// possible to assist in debugging and testing of the new code base by comparing performance/results, etc. with the 2.x
/// code base.
/// </remarks>
/// <param name="weightScale"></param>
/// <returns>A new instance of <see cref="WeightMutationScheme"/>.</returns>
public static WeightMutationScheme <double> CreateDefaultScheme(
double weightScale, IRandomSourceBuilder rngBuilder)
{
var probabilityArr = new double[6];
var strategyArr = new IWeightMutationStrategy <double> [6];
IRandomSource rng = rngBuilder.Create();
// Gaussian delta with sigma=0.01 (most values between +-0.02)
// Mutate 1, 2 and 3 connections respectively.
probabilityArr[0] = 0.5985;
probabilityArr[1] = 0.2985;
probabilityArr[2] = 0.0985;
strategyArr[0] = CreateCardinalGaussianDeltaStrategy(1, 0.1, rngBuilder);
strategyArr[1] = CreateCardinalGaussianDeltaStrategy(2, 0.1, rngBuilder);
strategyArr[2] = CreateCardinalGaussianDeltaStrategy(3, 0.1, rngBuilder);
// Reset mutations. 1, 2 and 3 connections respectively.
probabilityArr[3] = 0.015;
probabilityArr[4] = 0.015;
probabilityArr[5] = 0.015;
strategyArr[3] = CreateCardinalUniformResetStrategy(1, weightScale, rngBuilder);
strategyArr[4] = CreateCardinalUniformResetStrategy(2, weightScale, rngBuilder);
strategyArr[5] = CreateCardinalUniformResetStrategy(3, weightScale, rngBuilder);
return(new WeightMutationScheme <double>(probabilityArr, strategyArr, rngBuilder.Create()));
}
public NeatReproductionSexual(
MetaNeatGenome <T> metaNeatGenome,
INeatGenomeBuilder <T> genomeBuilder,
Int32Sequence genomeIdSeq,
Int32Sequence innovationIdSeq,
Int32Sequence generationSeq,
AddedNodeBuffer addedNodeBuffer,
NeatReproductionSexualSettings settings,
IRandomSourceBuilder rngBuilder)
{
_settings = settings;
_rng = rngBuilder.Create();
_strategy = new UniformCrossoverReproductionStrategy <T>(
metaNeatGenome, genomeBuilder,
genomeIdSeq, generationSeq,
rngBuilder.Create());
}
public NeatReproductionAsexual(
MetaNeatGenome <T> metaNeatGenome,
INeatGenomeBuilder <T> genomeBuilder,
Int32Sequence genomeIdSeq,
Int32Sequence innovationIdSeq,
Int32Sequence generationSeq,
AddedNodeBuffer addedNodeBuffer,
NeatReproductionAsexualSettings settings,
WeightMutationScheme <T> weightMutationScheme,
IRandomSourceBuilder rngBuilder)
{
_settings = settings;
_rngBuilder = rngBuilder;
_rng = rngBuilder.Create();
// Instantiate reproduction strategies.
_mutateWeightsStrategy = new MutateWeightsStrategy <T>(metaNeatGenome, genomeBuilder, genomeIdSeq, generationSeq, weightMutationScheme);
_deleteConnectionStrategy = new DeleteConnectionStrategy <T>(metaNeatGenome, genomeBuilder, genomeIdSeq, generationSeq, rngBuilder.Create());
// Add connection mutation; select acyclic/cyclic strategy as appropriate.
if (metaNeatGenome.IsAcyclic)
{
_addConnectionStrategy = new AddAcyclicConnectionStrategy <T>(
metaNeatGenome, genomeBuilder,
genomeIdSeq, innovationIdSeq, generationSeq,
rngBuilder.Create());
}
else
{
_addConnectionStrategy = new AddCyclicConnectionStrategy <T>(
metaNeatGenome, genomeBuilder,
genomeIdSeq, innovationIdSeq, generationSeq,
rngBuilder.Create());
}
_addNodeStrategy = new AddNodeStrategy <T>(metaNeatGenome, genomeBuilder, genomeIdSeq, innovationIdSeq, generationSeq, addedNodeBuffer, rngBuilder.Create());
}
static RandomDefaults()
{
DefaultRandomSeedSource = new DefaultRandomSeedSource();
DefaultRandomSourceBuilder = new Xoshiro256StarStarRandomBuilder(DefaultRandomSeedSource);
}
