/// <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> /// Retrieves the activation function from the given style. /// </summary> /// <param name="style">The style corresponding to the function.</param> /// <returns>The desired activation function.</returns> public static Func <double, double> GetActivationFunction(ActivationStyle style) { switch (style) { case ActivationStyle.SigmoidBasic: return(Sigmoid); case ActivationStyle.SigmoidNEAT: return(SigmoidNEAT); case ActivationStyle.ReLU: return(ReLU); case ActivationStyle.None: return(UnitLine); default: throw new Exception("ActivationFunctions.GetActivationFunction style not found."); break; } return(Sigmoid); }
/// <summary> /// Basic constructor. /// </summary> /// <param name="type">The type of the node.</param> /// <param name="aFun">The function to be used in activation.</param> public NodeInformation(NodeType type, ActivationStyle style) { Type = type; Style = style; }
/// <summary> /// Constructs a MutationStyle.AddNode innovation. /// </summary> /// <param name="conInfo">The original connection being broke.</param> /// <param name="style">The ActivationStyle of the new node.</param> public InnovationInformation(ConnectionInformation conInfo, ActivationStyle style) { InnovationType = MutationStyle.AddNode; ConnectionInformation = conInfo; Style = style; }