public void FormDiscreteEquation(out double[,] matrix, out double[] rightPart, Func <double, int, double> matrixModifier = null, Func <double, int, double> rightPartModifier = null)
{
double H = CalculateDiscreteStep(PointsNumber);
// calculate right part vector
rightPart = new double[this.PointsNumber];
double ti = 0;
for (int i = 0; i < PointsNumber; i++)
{
rightPart[i] = rightPartModifier?.Invoke(RightPartFunction(ti), i) ?? RightPartFunction(ti);
ti += H;
}
// calculate matrix
matrix = new double[PointsNumber, PointsNumber];
double sj = 0;
ti = 0;
for (int i = 0; i < PointsNumber; i++)
{
Core.Prepare(ti);
sj = 0;
for (int j = 0; j < PointsNumber; j++)
{
matrix[i, j] = matrixModifier?.Invoke(Core.GetValue(sj), j) ?? Core.GetValue(sj);
sj += H;
}
ti += H;
}
}
public void FormDiscreteEquation(out double[,] matrix, out double[] rightPart, int columnsNumber, Func <double, int, double> rightPartModifier)
{
double H = CalculateDiscreteStep(PointsNumber);
// calculate right part vector
rightPart = new double[this.PointsNumber];
double ti = 0;
for (int i = 0; i < PointsNumber; i++)
{
rightPart[i] = rightPartModifier?.Invoke(RightPartFunction(ti), i) ?? RightPartFunction(ti);
ti += H;
}
// calculate matrix
int columnsPerCore = columnsNumber / 2; // chebichev polinom power
matrix = new double[PointsNumber, columnsNumber];
double sj = 0;
ti = 0;
for (int i = 0; i < PointsNumber; i++)
{
CoreFirst.Prepare(ti);
CoreSecond.Prepare(ti);
for (int k = 0; k < columnsPerCore; k++)
{
matrix[i, k] = CoreFirst.GetValue(k);
matrix[i, k + columnsPerCore] = CoreSecond.GetValue(k);
}
ti += H;
}
}
// for periodiŃ cores with smooth part f on [0, 2*PI]x[0, 2*PI]
public static double CalculateWithWeakSingularCore(DoubleCore <double> f, int n)
{
n = DevideByTwo(n);
int N = 2 * n;
double temp = 0;
double h = Math.PI / n;
double sum = 0;
for (int i = 0; i < N; i++)
{
sum += f.GetValue(temp) * CoefficientForWeakSingular(f.Param, N, temp);
temp += h;
}
return(sum * 2.0 * Math.PI);
}
