private static float CostFunction(Single1D aa, Single1D yy, CostFunctionEnum costFunction)
{
return(costFunction switch
{
CostFunctionEnum.Quadratic => QuadraticCostFunction(aa, yy),
CostFunctionEnum.CrossEntropy => CrossEntropyCostFunction(aa, yy),
_ => throw new InvalidCaseException(nameof(costFunction), costFunction, 386203),
});
// ----------------------------------------------------------------------------------------
#region Network
public float GetCostAndDerivatives(
SampleList samples, Single1D derivatives, MeasurementList measurements,
CalculationArguments arguments)
{
CostFunctionEnum costFunction = arguments.settings.CostFunction;
float lambda = arguments.settings.Lambda;
int nSamples = samples.Count;
int nCoeffs = derivatives.Count;
float cost = 0f;
Layer last = Last;
for (int i = 0; i < nCoeffs; i++)
{
derivatives[i] = 0f;
}
for (int iSample = 0; iSample < nSamples; iSample++)
{
arguments.ThrowIfCancellationRequested();
Sample sample = samples[iSample];
Single1D measurement = measurements[iSample];
Input.SetActivations(sample.Inputs, 0);
FeedForward(true);
last.GetActivations(measurement, 0);
cost += CostFunction(measurement, sample.Requirements, costFunction);
int weightCount = CountWeight();
cost += 0.5f * lambda * SumWeightSqr() / weightCount; // regularization
last.CalculateDeltas(sample.Requirements, costFunction);
FeedBackward(true);
AddDerivatives(derivatives, 0, lambda / weightCount);
arguments.reporter?.ReportProgress(iSample, nSamples);
}
arguments.reporter?.ReportProgress(0, nSamples);
cost /= nSamples;
for (int i = 0; i < nCoeffs; i++)
{
derivatives[i] /= nSamples;
}
return(cost);
}
public virtual void CalculateDeltas(Single1D ys, CostFunctionEnum costFunction)
// This must be the last layer in the network
{
}
