/// <summary>
/// Mutates a genome by breaking a connection up into two separate connections.
/// </summary>
/// <param name="genome">The genome to be modified.</param>
/// <param name="innovationsSeen">A list of previously seen innovations.</param>
/// <param name="rando">A random number generator.</param>
public static void MutateAddNode(Genome genome, InnovationPool innovationsSeen, Random rando)
{
List <Gene> possibleConnections = new List <Gene>(genome.Genes);
possibleConnections.RemoveAll(x => x.Frozen || NodePool.FindById(x.link.InNode).Type == NodeType.BIAS);
if (possibleConnections.Count == 0)
{
return;
}
//TODO: Note in original algorithm saying uniform distribution is not optimal here.
Gene geneToSplit = possibleConnections[rando.Next(possibleConnections.Count)];
geneToSplit.Frozen = true;
ActivationStyle style = ActivationFunctions.ChooseActivationStyle(rando);
InnovationInformation innovation = new InnovationInformation(geneToSplit.link, style);
int firstConId = -1;
int secondConId = -1;
int registeredInnovationId = innovationsSeen.FindByInnovation(innovation);
if (registeredInnovationId == -1)
{
int newNodeId = NodePool.Add(new NodeInformation(NodeType.HIDDEN, style));
ConnectionInformation firstConnect = new ConnectionInformation(geneToSplit.link.InNode, newNodeId);
firstConId = ConnectionPool.Add(firstConnect);
ConnectionInformation secondConnect = new ConnectionInformation(newNodeId, geneToSplit.link.OutNode);
secondConId = ConnectionPool.Add(secondConnect);
innovation.NewNodeDetails.NewNodeId = newNodeId;
innovation.NewNodeDetails.FirstConnectionId = firstConId;
innovation.NewNodeDetails.SecondConnectionId = secondConId;
innovationsSeen.Add(innovation);
}
else
{
InnovationInformation registeredInnovation = innovationsSeen.FindById(registeredInnovationId);
firstConId = registeredInnovation.NewNodeDetails.FirstConnectionId;
secondConId = registeredInnovation.NewNodeDetails.SecondConnectionId;
}
genome.Genes.Add(new Gene(ConnectionPool.FindById(firstConId), firstConId, 1.0, false));
genome.Genes.Add(new Gene(ConnectionPool.FindById(secondConId), secondConId, geneToSplit.Weight, false));
}
/// <summary>
/// Mutates a given genome by adding a connection.
/// Connection is guaranteed to not be 'into' a sensor or bias.
/// </summary>
/// <param name="genome">The genome to be modified.</param>
/// <param name="innovationsSeen">A list of previously seen innovations.</param>
/// <param name="rando">A random number generator.</param>
public static void MutateAddConnection(Genome genome, InnovationPool innovationsSeen, Random rando)
{
//TODO: I'm getting the node information, but I only need that to construct allNodesNotInput...
Dictionary <int, NodeInformation> allNodes = genome.GetAllNodeInformation(true);
Dictionary <int, NodeInformation> allNodesNotInput = new Dictionary <int, NodeInformation>(allNodes);
//TODO: Witnessed a bug where allNodes.Count == 0.
// Could be a node where there are only frozen links connecting.
foreach (var id in allNodesNotInput.Where(kvp => kvp.Value.IsInput()).ToList())
{
allNodesNotInput.Remove(id.Key);
}
//TODO: Gotta be a better way than a tryCount...
int tryCount = 0;
int nodeFromId = -1;
int nodeToId = -1;
while (tryCount < 20)
{
nodeFromId = allNodes.Keys.ToList()[rando.Next(allNodes.Count)];
nodeToId = allNodesNotInput.Keys.ToList()[rando.Next(allNodesNotInput.Count)];
if (!genome.ContainsConnection(nodeFromId, nodeToId))
{
break;
}
tryCount++;
}
if (tryCount == 20)
{
return;
}
ConnectionInformation connectInfo = new ConnectionInformation(nodeFromId, nodeToId);
InnovationInformation innovation = new InnovationInformation(connectInfo);
int connectId = -1;
//TODO: Pull inital weight setting out of here.
double weight = rando.NextDouble() * 2.0 - 1.0;
int registeredInnovationId = innovationsSeen.FindByInnovation(innovation);
if (registeredInnovationId == -1)
{
connectId = ConnectionPool.Add(connectInfo);
innovation.NewConnectionDetails.ConnectionId = connectId;
innovationsSeen.Add(innovation);
}
else
{
connectId = innovationsSeen.FindById(registeredInnovationId).NewConnectionDetails.ConnectionId;
}
genome.Genes.Add(new Gene(ConnectionPool.FindById(connectId), connectId, weight, false));
}