/// <summary>
/// Override that randomly assigns activation functions to neuron's from an activation function library
/// based on each library item's selection probability.
/// </summary>
public override NeuronGene CreateNeuronGene(uint innovationId, NodeType neuronType)
{
switch (neuronType)
{
case NodeType.Bias:
case NodeType.Input:
{ // Use the ID of the first function. By convention this will be the a sigmoid function in nEAT and RBF-NEAT
// but in actual fact bias and input neurons don't use their activation function.
int activationFnId = _activationFnLibrary.GetFunctionList()[0].Id;
return(new NeuronGene(innovationId, neuronType, activationFnId));
}
default:
{
ActivationFunctionInfo fnInfo = _activationFnLibrary.GetRandomFunction(_rng);
IActivationFunction actFn = fnInfo.ActivationFunction;
double[] auxArgs = null;
if (actFn.AcceptsAuxArgs)
{
auxArgs = actFn.GetRandomAuxArgs(_rng, _neatGenomeParamsCurrent.ConnectionWeightRange);
}
return(new NeuronGene(innovationId, neuronType, fnInfo.Id, auxArgs));
}
}
}
private void PaintLegend(PaintState state)
{
const int LineHeight = 16;
const int Margin = 10;
IList <ActivationFunctionInfo> fnList = _activationFnLibrary.GetFunctionList();
int count = fnList.Count;
// Determine y position of first line.
int yCurr = Math.Max(Margin, state._viewportArea.Height - ((count * LineHeight) + Margin));
for (int i = 0; i < count; i++, yCurr += LineHeight)
{
ActivationFunctionInfo fnInfo = fnList[i];
const int X = Margin;
// Paint an example node as part of the legend item.
Point p = new Point(X, yCurr);
Size s = new Size(state._nodeDiameter, state._nodeDiameter);
Rectangle r = new Rectangle(p, s);
// Paint the node. Fill first and then border, this gives a clean border.
Graphics g = state._g;
Brush fillBrush = _brushNodeFillArr[fnInfo.Id % _brushNodeFillArr.Length];
g.FillRectangle(fillBrush, r);
g.DrawRectangle(__penBlack, r);
// Write the activation function string ID.
g.DrawString(fnList[i].ActivationFunction.FunctionId, __fontNodeTag, __brushBlack, X + 12, yCurr - 1);
}
}
/// <summary>
/// Construct with a single IActivationFunction.
/// </summary>
/// <param name="activationFn"></param>
public NeatActivationFunctionLibrary(IActivationFunction activationFn)
{
_activationFn = activationFn;
_activationFnInfo = new ActivationFunctionInfo(0, 1.0, activationFn);
_activationFnInfoList = new List <ActivationFunctionInfo>(1);
_activationFnInfoList.Add(_activationFnInfo);
}
