private double FreshetByYCoreFunction(double t, double k)
{
double H = IntegralEquationDiscretezer.CalculateDiscreteStep(PointsNumber);
double coreSum = 0;
double sj = 0;
for (int j = 0; j < PointsNumber; j++)
{
double x = InnerCurve.GetX(sj), y = InnerCurve.GetY(sj),
dx = InnerCurve.GetDerivetiveX(sj), dy = InnerCurve.GetDerivetiveY(sj);
double denominator = x * x + y * y
+ Radius * Radius - 2.0 * x * Radius * Math.Cos(t)
- 2.0 * y * Radius * Math.Sin(t);
double firstTerm = -(x * x + y * y - Radius * Radius)
* (2.0 * y - 2.0 * Radius * Math.Sin(t))
/ (2.0 * Math.PI * Radius * Math.Pow(denominator, 2));
double secondTerm = y / (Math.PI * Radius * denominator);
double result = (firstTerm + secondTerm) / 2.0;
double derivetiveNorm = dx * dx + dy * dy;
double dataEquationCore = DataEquationOperatorCore(new Point(Radius * Math.Cos(t), Radius * Math.Sin(t)),
new Point(x, y));
coreSum += (2.0 * Math.PI / PointsNumber) * Density[j]
* (result * Math.Cos(k * sj) + dataEquationCore * dy * ChebishevPolDerivative(k, sj) / derivetiveNorm);// додано двійку без формули 2.0 * dataEquationCore
//coreSum += (2.0 * Math.PI / PointsNumber) * Density[j]
// * (result * Math.Cos(k * sj));
sj += H;
}
return(coreSum);
}
private double H(double t, double tau)
{
if (Math.Abs(t - tau) > DeviationEps)
{
double curveDeviation = Math.Pow(InnerCurve.GetX(t) - InnerCurve.GetX(tau), 2)
+ Math.Pow(InnerCurve.GetY(t) - InnerCurve.GetY(tau), 2);
double denominator = Math.E * Math.E * curveDeviation;
double numerator = 4.0 * Math.Pow(Math.Cos(t) - Math.Cos(tau), 2);
return(Math.Log(numerator / denominator) / (4.0 * Math.PI)
+ GrinFunction(t, tau));
}
else
{
double curveAbs = Math.Pow(InnerCurve.GetDerivetiveX(t), 2)
+ Math.Pow(InnerCurve.GetDerivetiveY(t), 2);
double logParam = 4.0 / (Math.E * Math.E * curveAbs);
double result = Math.Log(logParam) / (4.0 * Math.PI)
+ GrinFunction(t, t);
return(result);
}
}
