// Add new connection to the network
public Result AddConnection()
{
// Select a random node which will have an extra connections
// Do not select nodes in the output layer
// Check if network is fully connected
if (IsNetworkFullyConnected())
{
return(Result.fail);
}
Node fromNode = null;
do
{
// Select a random node
int rndNodeNumb = MyRand.Next(0, Nodes.Count);
fromNode = Nodes[rndNodeNumb];
//Find new node if this node is fully connected, OR in the output layer
} while(IsNodeInOutputLayer(fromNode) ||
IsNodeFullyConnected(fromNode)
);
// Find a node to connect to
Node toNode = null;
do
{
// Select a random node
int rndNodeNumb = MyRand.Next(0, Nodes.Count);
toNode = Nodes[rndNodeNumb];
// Find new node if this node is in the same layer, OR both already connected
} while((toNode.Layer == fromNode.Layer) ||
(IsConnected(fromNode, toNode))
);
//If the tonode is in a lower layer than the fromnode, change positon
if (toNode.Layer < fromNode.Layer)
{
Node tmp = toNode;
toNode = fromNode;
fromNode = tmp;
}
// Add connections between the two nodes with random weight
Connection newConn = new Connection(fromNode);
newConn.ONode = toNode;
fromNode.Connections.Add(newConn);
Connections.Add(newConn);
// Assign innovation ID for new connection
InnovationHandler.GetInnovationID(newConn);
return(Result.success);
}
// Add new node on an existing connection
public Result AddNode()
{
if (Connections.Count == 0)
{
//Cannot Add new node
return(Result.fail);
}
//Get a random connection, it can be disabled too
int rndConnNumb = MyRand.Next(0, Connections.Count);
Connection rndConn = Connections[rndConnNumb];
//Deactivate this connection
rndConn.Enabled = false;
//Add a new node on it
Node newNode = new Node(NodeCnt);
NodeCnt++;
newNode.Layer = rndConn.INode.Layer + 1;
//Connect INode and new node
Connection conn1 = new Connection(rndConn.INode);
conn1.Weight = 1.0;
conn1.Bias = 0.0;
conn1.Enabled = true;
conn1.ONode = newNode;
InnovationHandler.GetInnovationID(conn1);
rndConn.INode.Connections.Add(conn1);
//TODO i could consider if the connection was disabled to create two "low" effect connections
//Connect new node and Onode
Connection conn2 = new Connection(newNode);
conn2.Weight = rndConn.Weight;
conn2.Bias = rndConn.Bias;
conn2.Enabled = true;
conn2.ONode = rndConn.ONode;
InnovationHandler.GetInnovationID(conn2);
newNode.Connections.Add(conn2);
//If the connection we are breaking is between layers that are next to eachother
//it means we need to add a new layer
//else we need to increase the first intermediate layer
if ((rndConn.INode.Layer + 1) == rndConn.ONode.Layer)
{
//New layer is needed
//Shift every layer by one after the new layer
foreach (var node in Nodes)
{
if (node.Layer > rndConn.INode.Layer)
{
node.Layer++;
}
}
OutputLayer++;
}
else if ((rndConn.INode.Layer + 1) < rndConn.ONode.Layer)
{
//Layer should already exist
}
else
{
throw new Exception("Error: The connection is wrong!");
}
//Finally add new object to the lists
Nodes.Add(newNode);
Connections.Add(conn1);
Connections.Add(conn2);
return(Result.success);
}