public void TestGaussian()
{
IRadialBasisFunction radial = new GaussianFunction(0.0, 1.0, 1.0);
var bubble = new NeighborhoodRBF1D(radial);
Assert.AreEqual(0.0, bubble.Function(5, 0), 0.1);
Assert.AreEqual(1.0, bubble.Function(5, 5), 0.1);
Assert.AreEqual(0.6, bubble.Function(5, 4), 0.1);
}
/// <summary>
/// Prune one of the neurons from this layer. Remove all entries in this
/// weight matrix and other layers.
/// </summary>
/// <param name="targetLayer">The neuron to prune. Zero specifies the first neuron.</param>
/// <param name="neuron">The neuron to prune.</param>
public void Prune(ILayer targetLayer, int neuron)
{
// delete a row on this matrix
foreach (ISynapse synapse in targetLayer.Next)
{
if (synapse.WeightMatrix != null)
{
synapse.WeightMatrix =
MatrixMath.DeleteRow(synapse.WeightMatrix, neuron);
}
}
// delete a column on the previous
ICollection<ILayer> previous = this.network.Structure
.GetPreviousLayers(targetLayer);
foreach (ILayer prevLayer in previous)
{
if (previous != null)
{
foreach (ISynapse synapse in prevLayer.Next)
{
if (synapse.WeightMatrix != null)
{
synapse.WeightMatrix =
MatrixMath.DeleteCol(synapse.WeightMatrix,
neuron);
}
}
}
}
// remove the bias
if (targetLayer.HasBias)
{
double[] newBias = new double[targetLayer
.NeuronCount - 1];
int targetIndex = 0;
for (int i = 0; i < targetLayer.NeuronCount; i++)
{
if (i != neuron)
{
newBias[targetIndex++] = targetLayer.BiasWeights[i];
}
}
targetLayer.BiasWeights = newBias;
}
// adjust RBF
if (targetLayer is RadialBasisFunctionLayer)
{
RadialBasisFunctionLayer rbf = (RadialBasisFunctionLayer)targetLayer;
IRadialBasisFunction[] newRBF = new GaussianFunction[targetLayer
.NeuronCount - 1];
int targetIndex = 0;
for (int i = 0; i < targetLayer.NeuronCount; i++)
{
if (i != neuron)
{
newRBF[targetIndex++] = rbf.RadialBasisFunction[i];
}
}
rbf.RadialBasisFunction = newRBF;
}
// update the neuron count
targetLayer.NeuronCount -= 1;
}
/// <summary>
/// Internal function to increase the neuron count. This will add a
/// zero-weight neuron to this layer.
/// </summary>
/// <param name="layer">The layer to increase.</param>
/// <param name="neuronCount">The new neuron count.</param>
private void IncreaseNeuronCount(ILayer layer, int neuronCount)
{
// adjust the bias
double[] newBias = new double[neuronCount];
if (layer.HasBias)
{
for (int i = 0; i < layer.NeuronCount; i++)
{
newBias[i] = layer.BiasWeights[i];
}
layer.BiasWeights = newBias;
}
// adjust the outbound weight matrixes
foreach (ISynapse synapse in layer.Next)
{
if (synapse.WeightMatrix != null)
{
Matrix newMatrix = new Matrix(neuronCount, synapse
.ToNeuronCount);
// copy existing matrix to new matrix
for (int row = 0; row < layer.NeuronCount; row++)
{
for (int col = 0; col < synapse.ToNeuronCount; col++)
{
newMatrix[row, col] = synapse.WeightMatrix[row, col];
}
}
synapse.WeightMatrix = newMatrix;
}
}
// adjust the inbound weight matrixes
ICollection<ISynapse> inboundSynapses = this.network.Structure
.GetPreviousSynapses(layer);
foreach (ISynapse synapse in inboundSynapses)
{
if (synapse.WeightMatrix != null)
{
Matrix newMatrix = new Matrix(synapse.FromNeuronCount,
neuronCount);
// copy existing matrix to new matrix
for (int row = 0; row < synapse.FromNeuronCount; row++)
{
for (int col = 0; col < synapse.ToNeuronCount; col++)
{
newMatrix[row, col] = synapse.WeightMatrix[row, col];
}
}
synapse.WeightMatrix = newMatrix;
}
}
// adjust the bias
if (layer.HasBias)
{
double[] newBias2 = new double[neuronCount];
for (int i = 0; i < layer.NeuronCount; i++)
{
newBias2[i] = layer.BiasWeights[i];
}
layer.BiasWeights = newBias2;
}
// adjust RBF
if (layer is RadialBasisFunctionLayer)
{
RadialBasisFunctionLayer rbf = (RadialBasisFunctionLayer)layer;
IRadialBasisFunction[] newRBF = new IRadialBasisFunction[neuronCount];
for (int i = 0; i < rbf.RadialBasisFunction.Length; i++)
{
newRBF[i] = rbf.RadialBasisFunction[i];
}
for (int i = rbf.RadialBasisFunction.Length; i < neuronCount; i++)
{
newRBF[i] = new GaussianFunction(ThreadSafeRandom.NextDouble() - 0.5,
ThreadSafeRandom.NextDouble(), ThreadSafeRandom.NextDouble() - 0.5);
}
rbf.RadialBasisFunction = newRBF;
}
// finally, up the neuron count
layer.NeuronCount = neuronCount;
}
