public Parameters(
List <Entity> entities,
List <List <Distance> > distancesForEachElement,
DistanceFunctionType distanceFunctionType,
WindowType windowType,
KernelFunctionType kernelFunctionType,
double windowWidth,
int neighborsCount)
{
Entities = entities;
DistancesForEachElement = distancesForEachElement;
DistanceFunctionType = distanceFunctionType;
WindowType = windowType;
KernelFunctionType = kernelFunctionType;
WindowWidth = windowWidth;
NeighborsCount = neighborsCount;
}
private static double CalculateKernel(double value, KernelFunctionType kernelFunctionType)
{
var kernel = 0d;
switch (kernelFunctionType)
{
case KernelFunctionType.Uniform:
if (Math.Abs(value) < 1)
{
kernel = 0.5;
}
break;
case KernelFunctionType.Triangular:
if (Math.Abs(value) < 1)
{
kernel = 1d - Math.Abs(value);
}
break;
case KernelFunctionType.Epanechnikov:
if (Math.Abs(value) < 1)
{
kernel = 0.75 * (1 - Math.Pow(value, 2));
}
break;
case KernelFunctionType.Quartic:
if (Math.Abs(value) < 1)
{
kernel = 15d / 16d * Math.Pow(1 - Math.Pow(value, 2), 2);
}
break;
case KernelFunctionType.Triweight:
if (Math.Abs(value) < 1)
{
kernel = 35d / 32d * Math.Pow(1d - Math.Pow(value, 2d), 3d);
}
break;
case KernelFunctionType.Tricube:
if (Math.Abs(value) < 1)
{
kernel = 70d / 81d * Math.Pow(1d - Math.Pow(Math.Abs(value), 3d), 3d);
}
break;
case KernelFunctionType.Gaussian:
kernel = Math.Exp(-Math.Pow(value, 2d) / 2d) / Math.Sqrt(2d * Math.PI);
break;
case KernelFunctionType.Cosine:
if (Math.Abs(value) < 1)
{
kernel = Math.PI * Math.Cos(Math.PI * value / 2d) / 4d;
}
break;
case KernelFunctionType.Logistic:
kernel = 1d / (Math.Exp(value) + 2d + Math.Exp(-value));
break;
case KernelFunctionType.Sigmoid:
kernel = 2d / (Math.PI * (Math.Exp(value) + Math.Exp(-value)));
break;
default:
break;
}
return(kernel);
}
