/// <summary>
/// Initializes a new instance of the <see cref="GEPChromosome"/> class.
/// </summary>
///
/// <param name="source">Source GEP chromosome to clone from.</param>
///
protected GEPChromosome(GEPChromosome source)
{
headLength = source.headLength;
length = source.length;
fitness = source.fitness;
// allocate genes array
genes = new IGPGene[length];
// copy genes
for (int i = 0; i < length; i++)
{
genes[i] = source.genes[i].Clone( );
}
}
/// <summary>
/// One-point recombination (crossover).
/// </summary>
///
/// <param name="pair">Pair chromosome to crossover with.</param>
///
public void RecombinationOnePoint(GEPChromosome pair)
{
// check for correct pair
if ((pair.length == length))
{
// crossover point
int crossOverPoint = rand.Next(length - 1) + 1;
// length of chromosome to be crossed
int crossOverLength = length - crossOverPoint;
// swap parts of chromosomes
Recombine(genes, pair.genes, crossOverPoint, crossOverLength);
}
}
/// <summary>
/// Crossover operator.
/// </summary>
///
/// <param name="pair">Pair chromosome to crossover with.</param>
///
/// <remarks><para>The method performs one-point or two-point crossover selecting
/// them randomly with equal probability.</para></remarks>
///
public override void Crossover(IChromosome pair)
{
GEPChromosome p = (GEPChromosome)pair;
// check for correct chromosome
if (p != null)
{
// choose recombination method
if (rand.Next(2) == 0)
{
RecombinationOnePoint(p);
}
else
{
RecombinationTwoPoint(p);
}
}
}
/// <summary>
/// Two point recombination (crossover).
/// </summary>
///
/// <param name="pair">Pair chromosome to crossover with.</param>
///
public void RecombinationTwoPoint(GEPChromosome pair)
{
// check for correct pair
if ((pair.length == length))
{
// crossover point
int crossOverPoint = rand.Next(length - 1) + 1;
// length of chromosome to be crossed
int crossOverLength = length - crossOverPoint;
// if crossover length already equals to 1, then it becomes
// usual one point crossover. otherwise crossover length
// also randomly chosen
if (crossOverLength != 1)
{
crossOverLength = rand.Next(crossOverLength - 1) + 1;
}
// swap parts of chromosomes
Recombine(genes, pair.genes, crossOverPoint, crossOverLength);
}
}