/// <summary>
/// Mutates a gene by applying boundary mutation.
/// </summary>
/// <param name="gene">An IntegerGene or DoubleGene to be mutated.</param>
/// <returns></returns>
public static Gene Mutate(Gene gene)
{
if ( gene is IntegerGene )
{
IntegerGene ig = (IntegerGene)gene;
if ( genX.Utils.Rand.NextDouble() < 0.5 )
{
ig.Value = ig.Descriptor.MaxValue;
}
else
{
ig.Value = ig.Descriptor.MinValue;
}
}
else if ( gene is DoubleGene )
{
DoubleGene dg = (DoubleGene)gene;
if ( genX.Utils.Rand.NextDouble() < 0.5 )
{
dg.Value = dg.Descriptor.MaxValue;
}
else
{
dg.Value = dg.Descriptor.MinValue;
}
}
else
{
throw new ArgumentException(
"Boundary mutation may only apply to IntegerGene or DoubleGene genes.",
"gene"
);
}
return gene;
}
/// <summary>
/// Mutates a gene by bitwise mutation.
/// </summary>
/// <param name="gene"></param>
/// <returns></returns>
public static Gene Mutate(Gene gene)
{
if ( gene is BinaryGene )
{
BinaryGene g = (BinaryGene) gene.Clone();
g.Value = !(BinaryGene)gene;
return g;
}
else if ( gene is DoubleGene )
{
DoubleGene g = (DoubleGene) gene.Clone();
byte[] bytes = BitConverter.GetBytes(g.Value);
BitArray ba = new BitArray(bytes);
int p = Utils.Rand.Next( ba.Length );
ba.Set(p, !ba[p]);
ba.CopyTo(bytes, 0);
g.Value = BitConverter.ToDouble(bytes,0);
return g;
}
else if ( gene is IntegerGene )
{
IntegerGene g = (IntegerGene) gene.Clone();
byte[] bytes = BitConverter.GetBytes(g.Value);
BitArray ba = new BitArray(bytes);
int p = Utils.Rand.Next( ba.Length );
ba.Set(p, !ba[p]);
ba.CopyTo(bytes, 0);
g.Value = BitConverter.ToInt32(bytes,0);
return g;
}
return (Gene) gene.Clone(); // default
}
/// <summary>
/// Mutates a gene.
/// </summary>
/// <param name="g"></param>
/// <returns></returns>
public virtual Gene Mutate(Gene g)
{
if (Mutator != null)
{
return(Mutator(g));
}
else
{
Gene g2 = GetRandomAllele();
g2.Label = g.Label;
return(g2);
}
}
void Mutate(Chromosome[] cs)
{
foreach (Chromosome c in cs)
{
//
// Mutate a gene's value in this chromosome.
//
if (Utils.Rand.NextDouble() < GeneMutationProbability)
{
int mutationPoint = Utils.Rand.Next(c.Genes.Length);
Gene gene = c.Genes[mutationPoint];
//
// A globally installed valuemutator takes precedence over the
// default gene mutator.
//
if (ValueMutator != null)
{
c.Genes[mutationPoint] = ValueMutator(gene);
}
else
{
// this is the Custom case
c.Genes[mutationPoint] = gene.Descriptor.Mutate(gene);
}
//
// Raise the Mutated event.
//
MutatedEventArgs e = new MutatedEventArgs();
e.Chromosome = c;
e.MutationPoint = mutationPoint;
e.OldGene = gene;
e.NewGene = c.Genes[mutationPoint];
OnMutated(e);
}
#if NOTDEF
if (Utils.Rand.NextDouble() < OrderMutationProbability)
{
if (OrderMutator != null)
{
OrderMutator(c);
}
}
#endif
}
}
/// <summary>
/// Initializes a chromosome with a given set of genes.
/// </summary>
/// <param name="genes">
/// An array of Genes with which to initailize. Each Gene in the array
/// may be of any derived type.
/// </param>
public Chromosome(Gene[] genes)
{
this.Genes = genes;
this.Parents = new Chromosome[2];
}
/// <summary>
/// Mutates a gene.
/// </summary>
/// <param name="g"></param>
/// <returns></returns>
public virtual Gene Mutate(Gene g)
{
if ( Mutator != null )
{
return Mutator(g);
}
else
{
Gene g2 = GetRandomAllele();
g2.Label = g.Label;
return g2;
}
}
