/// <summary>
/// Processes a training sample.
/// </summary>
/// <param name="connections">The inter-layer connections.</param>
/// <param name="activatedLeft">The activated units in the left partition.</param>
/// <param name="activatedRight">The activated units in the right partition.</param>
public override void ProcessSample(IInterLayerConnections connections, List <int> activatedLeft, List <int> activatedRight)
{
var random = ThreadSafeRandom.GetThreadRandom();
foreach (var outputUnit in activatedRight)
{
//
// Find out how many strong (excitatory) edges are connected to this unit
//
int degree = connections.GetNeighbours(outputUnit, Partition.Right, true).Count();
//
// If it's equal to the target degree, move on to the next output unit
//
if (degree == this.targetDegree)
{
////Debug.WriteLine("Skipping output unit " + outputUnit + " because it has reached its target degree");
continue;
}
//
// Calculate the probability of an edge strengthening/weakening
//
double p = (double)(this.targetDegree - degree) / (2.0 * this.MaxInputActivations);
//
// Stochastically modify edges which connect concurrently active units
//
foreach (var inputUnit in activatedLeft)
{
var edge = connections.GetEdge(inputUnit, outputUnit);
if (edge.Weight == 0 && p > 0.0 && random.NextDouble() < p)
{
connections.SetEdge(inputUnit, outputUnit, 1);
#if DEBUG
Debug.WriteLine("Adding edge between " + inputUnit + " and " + outputUnit);
#endif
}
else if (edge.Weight == 1 && p < 0.0 && random.NextDouble() < -p)
{
connections.SetEdge(inputUnit, outputUnit, 0);
#if DEBUG
Debug.WriteLine("Removing edge between " + inputUnit + " and " + outputUnit);
#endif
}
}
}
//
// TODO: Prune from the left as well?
//
}
/// <summary>
/// Processes a training sample.
/// </summary>
/// <param name="connections">The inter-layer connections.</param>
/// <param name="activatedLeft">The activated units in the left partition.</param>
/// <param name="activatedRight">The activated units in the right partition.</param>
public override void ProcessSample(IInterLayerConnections connections, List <int> activatedLeft, List <int> activatedRight)
{
var random = ThreadSafeRandom.GetThreadRandom();
foreach (var leftUnit in activatedLeft)
{
foreach (var rightUnit in activatedRight)
{
if (connections.GetEdge(leftUnit, rightUnit).Weight == 0)
{
if (random.NextDouble() < this.strengtheningProbability)
{
connections.SetEdge(leftUnit, rightUnit, 1);
}
}
}
}
}