/// <summary>
/// Adds Connection (Structural Mutation) to Genome from Nodes
/// </summary>
/// <param name="nodeFrom">From-Node for Connection</param>
/// <param name="nodeTo">To-Node for Connection</param>
internal void MutateAddConnection(NodeGene nodeFrom, NodeGene nodeTo)
{
if (!nodeFrom.IsValid)
{
throw new ArgumentException("NodeFrom is Invalid", "nodeFrom");
}
if (!nodeTo.IsValid)
{
throw new ArgumentException("NodeTo is Invalid", "nodeTo");
}
if (nodeFrom.Equals(nodeTo))
{
throw new ArgumentException("Cannot create Connection with a single Node");
}
if (!Nodes.ContainsKey(nodeFrom.Innovation))
{
throw new ArgumentException("Node does not exist in Genome", "nodeFrom");
}
if (!Nodes.ContainsKey(nodeTo.Innovation))
{
throw new ArgumentException("Node does not exist in Genome", "nodeTo");
}
if (nodeFrom.Type == NodeType.OUTPUT || nodeTo.Type == NodeType.INPUT)
{
throw new InvalidOperationException($"Invalid NodeTypes for Connection. Type NodeFrom: {nodeFrom.Type} Type NodeTo: {nodeTo.Type}");
}
// TODO: Check if Connection does not exist already in Genome
AddConnection(MutationFactory.GetConnection(nodeFrom, nodeTo));
}
/// <summary>
/// Adds random connection (Structural Mutation) to Genome
/// </summary>
internal void MutateAddRandomConnection()
{
if (Nodes.Count < 2)
{
throw new InvalidOperationException("Not enough Existing Nodes");
}
// Separate out the Nodes by Type
List <NodeGene> inputNodes = new List <NodeGene>();
List <NodeGene> hiddenNodes = new List <NodeGene>();
List <NodeGene> outputNodes = new List <NodeGene>();
foreach (NodeGene node in Nodes.Values)
{
switch (node.Type)
{
case NodeType.INPUT:
inputNodes.Add(node);
break;
case NodeType.HIDDEN:
hiddenNodes.Add(node);
break;
case NodeType.OUTPUT:
outputNodes.Add(node);
break;
default:
break;
}
}
// Add hiddenNodes to both lists to create the choice-lists
inputNodes.AddRange(hiddenNodes);
outputNodes.AddRange(hiddenNodes);
// Find 2 nodes in these 2 lists which are NOT connected
NodeGene inputNode = inputNodes[Functions.GetRandomNumber(0, inputNodes.Count)]; // Pick random inputNode
int attempts = 0;
while (attempts < MaxFindAttempts) // TODO: Improve this
{
attempts++;
NodeGene outputNode = outputNodes[Functions.GetRandomNumber(0, outputNodes.Count)];
if (inputNode.Equals(outputNode)) // Same (hidden) node, can't connect to self
{
continue;
}
bool foundConnection = false;
foreach (ConnectionGene conn in Connections.Values)
{
if (conn.HasNode(inputNode) && conn.HasNode(outputNode))
{
foundConnection = true;
break; // Connection Exists
}
}
if (foundConnection)
{
continue; // failed to find valid pair
}
// InputNode != OutputNode and !(I->O) && !(O->I)
AddConnection(MutationFactory.GetConnection(inputNode, outputNode));
return;
}
Console.WriteLine("Failed to add Connection");
}