/// <summary>
/// Perform a single point crossover.
/// </summary>
public static void Mutate(ICell cell)
{
if (cell == null) throw new ArgumentNullException("cell");
// Iterate the tags and the resources within the tags
for (int i = 0; i < cell.ActiveTagsInModel; i++)
{
// Potentially modify existing tag resources
Tag activeTag = cell.GetTagByIndex(i);
for (int j = 0; j < activeTag.Data.Count; j++)
{
if (ShouldMutateThisPoint())
{
activeTag.Data[j] = Resource.Random(true);
}
}
// Potentially add a resource
if (activeTag.Data.Count < Tag.MaxSize && ShouldMutateThisPoint())
{
int insertionIndex = RandomProvider.Next(0, activeTag.Data.Count);
activeTag.Data.Insert(insertionIndex, Resource.Random(true));
}
// Potentially remove a resource
if (activeTag.Data.Count > 2 && ShouldMutateThisPoint())
{
activeTag.Data.RemoveRandom();
}
}
}
/// <summary>
/// Perform a multi-point crossover.
/// </summary>
protected override IList<ICell> Reproduce(ICell actor, ICell target)
{
if (actor == null) throw new ArgumentNullException("actor");
if (target == null) throw new ArgumentNullException("target");
// Percentage of each tag crossing over is normalized to produce one
// cross on average by default. This is modified by the CrossoverFactor.
int crossoverPercent = (int) (100 / actor.ActiveTagsInModel * CrossoverFactor);
ICell child1 = actor.CreateEmptyCell();
ICell child2 = actor.CreateEmptyCell();
for (int i = 0; i < actor.ActiveTagsInModel; i++)
{
if (RandomProvider.Next(100) < crossoverPercent)
{
Tag actorTag = actor.GetTagByIndex(i);
Tag targetTag = target.GetTagByIndex(i);
Tag childTag1 = null;
Tag childTag2 = null;
CrossoverInteraction.CrossOverTags(actorTag, targetTag, out childTag1, out childTag2);
child1.SetTagByIndex(i, childTag1);
child2.SetTagByIndex(i, childTag2);
}
else
{
child1.SetTagByIndex(i, Tag.New(actor.GetTagByIndex(i)));
child2.SetTagByIndex(i, Tag.New(target.GetTagByIndex(i)));
}
}
if (AllowMutation)
{
PointMutation.Mutate(child1);
PointMutation.Mutate(child1);
}
return new List<ICell>() { child1, child2 };
}
/// <summary>
/// Perform a single point crossover.
/// </summary>
protected override IList<ICell> Reproduce(ICell actor, ICell target)
{
if (actor == null) throw new ArgumentNullException("actor");
if (target == null) throw new ArgumentNullException("target");
// Select the tag to crossover
int crossoverIndex = RandomProvider.Next(0, actor.ActiveTagsInModel - 1);
// Create two new cells like this (assuming crossover in tag 3):
//
// AAAA AAAA AATT TTTT
// TTTT TTTT TTAA AAAA
ICell child1 = actor.CreateEmptyCell();
ICell child2 = actor.CreateEmptyCell();
for (int i = 0; i < actor.ActiveTagsInModel; i++)
{
if (i < crossoverIndex)
{
child1.SetTagByIndex(i, Tag.New(actor.GetTagByIndex(i)));
child2.SetTagByIndex(i, Tag.New(target.GetTagByIndex(i)));
}
else if (i > crossoverIndex)
{
child1.SetTagByIndex(i, Tag.New(target.GetTagByIndex(i)));
child2.SetTagByIndex(i, Tag.New(actor.GetTagByIndex(i)));
}
else // i == crossoverIndex
{
// There are length+1 crossover points for a Tag (start, end, length-1 midpoints)
Tag actorTag = actor.GetTagByIndex(i);
Tag targetTag = target.GetTagByIndex(i);
Tag childTag1 = null;
Tag childTag2 = null;
CrossOverTags(actorTag, targetTag, out childTag1, out childTag2);
child1.SetTagByIndex(i, childTag1);
child2.SetTagByIndex(i, childTag2);
}
}
if (AllowMutation)
{
PointMutation.Mutate(child1);
PointMutation.Mutate(child1);
}
return new List<ICell>() {child1, child2};
}
