/// <summary>
/// Crossover operator.
/// </summary>
///
/// <param name="pair">Pair chromosome to crossover with.</param>
///
/// <remarks><para>The method performs crossover between two chromosomes ?interchanging
/// range of bits between these chromosomes.</para></remarks>
///
public override void Crossover(IChromosome pair)
{
BinaryChromosome p = (BinaryChromosome)pair;
// check for correct pair
if ((p != null) && (p.length == length))
{
int crossOverPoint = 63 - rand.Next(length - 1);
ulong mask1 = 0xFFFFFFFFFFFFFFFF >> crossOverPoint;
ulong mask2 = ~mask1;
ulong v1 = val;
ulong v2 = p.val;
// calculate new values
val = (v1 & mask1) | (v2 & mask2);
p.val = (v2 & mask1) | (v1 & mask2);
}
}
/// <summary>
/// Initializes a new instance of the <see cref="BinaryChromosome"/> class.
/// </summary>
///
/// <param name="source">Source chromosome to copy.</param>
///
/// <remarks><para>This is a copy constructor, which creates the exact copy
/// of specified chromosome.</para></remarks>
///
protected BinaryChromosome(BinaryChromosome source)
{
length = source.length;
val = source.val;
fitness = source.fitness;
}