public void Mutate()
{
// When no genes, add gene mutation
if (Connections.Count == 0)
{
AddConnection();
}
double chance = MyRand.UniformRnd(0, 1);
// 80% chance to modify weight or bias
if (chance < 0.8)
{
ModifyConnection();
}
chance = MyRand.UniformRnd(0, 1);
// 8% chance to add new connection
if (chance < 0.08)
{
AddConnection();
}
chance = MyRand.UniformRnd(0, 1);
// 2% chance to add new node
if (chance < 0.02)
{
AddNode();
}
// No mutations today
}
// 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);
}
/// <summary>
/// Random uniform weight, and enabled
/// </summary>
/// <param name="node">The input node</param>
public Connection(Node node)
{
INode = node;
Weight = MyRand.UniformRnd(-1, 1);
Bias = MyRand.UniformRnd(-1, 1);
Enabled = true;
ONode = null; // Output nodes are not necessary defined immediately
InnovID = 0; // It will be overwritten
}
/// <summary>
/// Adds a new player to the niche by crossover or cloning, could return null!
/// </summary>
public Player GetBaby()
{
// Need at least one player in this species
if (Members.Count < 1)
{
return(null);
}
Player newPlayer = null;
double chance = MyRand.UniformRnd(0, 1);
// TODO opt. In this case it is unnecessary to decide which species should this belong
// with 25% chance just clone a player || When we only have one member
if (chance < 0.25 || Members.Count == 1)
{
int rndPlayer = MyRand.Next(0, Members.Count);
newPlayer = Members[rndPlayer].DeepCopy();
newPlayer.SetFitness(0);
newPlayer.LifeSpawn = 0;
}
// Crossover 75% chance
else
{
// We cant do crossover if there are less than 2 players
if (Members.Count < 2)
{
return(null);
}
Player parentA = null;
Player parentB = null;
do
{
int rndPlayerNumb = MyRand.Next(0, Members.Count);
parentA = Members[rndPlayerNumb];
rndPlayerNumb = MyRand.Next(0, Members.Count);
parentB = Members[rndPlayerNumb];
} while(parentA.ID == parentB.ID);
if (parentA.Fitness > parentB.Fitness)
{
newPlayer = parentA.Crossover(parentB);
}
else
{
newPlayer = parentB.Crossover(parentA);
}
}
return(newPlayer);
}
// Toggle connection
public Result ToggleConnection()
{
// Check if we have connections or not
if (Connections.Count == 0)
{
//Cannot Add new node
return(Result.fail);
}
int rndConNumb = MyRand.Next(0, Connections.Count);
Connection conn = Connections[rndConNumb];
conn.Enabled = !conn.Enabled;
return(Result.success);
}
// Crossover this and NetworkB where this is the better parent
public Network Crossover(Network networkB)
{
// Create a child network, which is very similar to this network
Network child = new Network(InputNodes,
OutputNodes,
OutputLayer,
NodeCnt);
// At first we should Add the nodes, but how to choose which nodes to add?
// Chose the better parent which is this
foreach (var nodeA in Nodes)
{
Node childN = nodeA.DeepCopy(nodeA.ID);
// we will add the connections later
childN.Connections.Clear();
child.Nodes.Add(childN);
}
//Go through the genes, and decide how to use them
foreach (var conA in Connections)
{
bool enableGene = true;
Connection gene = null;
//Check if both parents have this gene
Connection conB = networkB.FindConnection(conA.InnovID);
if (conB != null)
{
//Both have this gene
//Check if it is disabled in any of the parent and with 75% chance
if ((!conA.Enabled || !conB.Enabled) &&
(MyRand.UniformRnd(0, 1) < Cfg.DisableUnnecessaryGene)
)
{
// These gene doesnt look necessary
enableGene = false;
}
//Decide who will give the gene
if (MyRand.UniformRnd(0, 1) < 0.50)
{
// Parent A
Node iNode = child.getNodeByID(conA.INode.ID);
Node oNode = child.getNodeByID(conA.ONode.ID);
gene = conA.DeepCopy(iNode, oNode);
iNode.Connections.Add(gene);
}
else
{
// Parent B
Node iNode = child.getNodeByID(conB.INode.ID);
Node oNode = child.getNodeByID(conB.ONode.ID);
gene = conB.DeepCopy(iNode, oNode);
iNode.Connections.Add(gene);
}
}
else
{
//Only parentA has this gene, disjoint or excess gene
Node iNode = child.getNodeByID(conA.INode.ID);
Node oNode = child.getNodeByID(conA.ONode.ID);
gene = conA.DeepCopy(iNode, oNode);
iNode.Connections.Add(gene);
}
gene.Enabled = enableGene;
child.Connections.Add(gene);
}
return(child);
}
// Modify an existing connection, can also be turned Off or On
public Result ModifyConnection()
{
// Check if we have connections or not
if (Connections.Count == 0)
{
//Cannot Add new node
return(Result.fail);
}
// Check if every connection is disabled, like in LoL
bool allDisabled = true;
foreach (var c in Connections)
{
if (c.Enabled)
{
allDisabled = false;
break;
}
}
if (allDisabled)
{
return(Result.fail);
}
// Select a connection which is not disabled
Connection conn = null;
do
{
int rndConNumb = MyRand.Next(0, Connections.Count);
conn = Connections[rndConNumb];
} while(!conn.Enabled);
// Slightly modify this connection's weight or bias
if (MyRand.UniformRnd(0, 1) > 0.3)
{
// Weight change
conn.Weight = MyRand.NormalDist(conn.Weight, 0.1);
// Not sure if limiting the weight is a good idea or not
if (conn.Weight > 1.0)
{
conn.Weight = 1.0;
}
if (conn.Weight < -1.0)
{
conn.Weight = -1.0;
}
}
else
{
// Bias change
conn.Bias = MyRand.NormalDist(conn.Bias, 0.1);
// Not sure if limiting the bias is a good idea or not
if (conn.Bias > 5.0)
{
conn.Bias = 5.0;
}
if (conn.Bias < -5.0)
{
conn.Bias = -5.0;
}
}
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);
}
// Kills the badly graded player/species and creates new ones
public void UnNaturalSelection()
{
// Kill player and species
for (int i = Species.Count - 1; i >= 0; i--)
{
// Determine the share of this species from the population
int share = (int)Math.Floor((Species[i].AvgFitness / SumAvgFitness) * Size);
// We should delete species with less members
if (share < Math.Ceiling(2 / (1 - Cfg.PlayersLeftAlive)))
{
Species.RemoveAt(i);
}
else
{
// Kill the halflings
Species[i].Bloodlust(share);
}
// DONT put anything after this, i-th element could be removed by now
}
// Iterate backwards so i can remove elements meanwhile
for (int i = 0; i < Species.Count; i++)
{
// Determine the share of this species from the population
int share = (int)Math.Floor((Species[i].AvgFitness / SumAvgFitness) * Size);
// Create new players replacing the dead
int newToCreate = share - Species[i].Members.Count;
for (int j = 0; j < newToCreate; j++)
{
Player newPlayer = Species[i].GetBaby();
// This shouldn't happen as we took precoutions just before
if (newPlayer == null)
{
throw new Exception($"Cannot generate a new player in this niche!");
}
// Mutate the new player
newPlayer.Mutate();
// Add this new player to a species,
// it could happen that it will have his own,
// or a different from where it was born
AddToSpecies(newPlayer);
}
}
// Checking number of players
int playerNum = 0;
foreach (var s in Species)
{
playerNum += s.Members.Count;
}
if (playerNum > Size)
{
throw new Exception("Too many players were assigned!");
}
// Because of rounding errors, some spaces are not filled it, fill them in
for (int space = 0; space < Size - playerNum; space++)
{
// Select a random species
int i = MyRand.Next(Species.Count);
// Get baby from the species
Player newPlayer = Species[i].GetBaby();
// Mutate the new player
newPlayer.Mutate();
// Add this new player to a species,
AddToSpecies(newPlayer);
}
}