static double[] Lap_Tien(double[,] Saiphan, double Y)
{
int n = Saiphan.GetLength(0);
double Giaithua = 1;
int k = 0;
double[] Pn = new double[n];
for (int i = 2; i < n; i++)
{
Giaithua *= i;
}
for (int i = n - 1; i >= 0; i--)
{
if (i == 0)
{
Pn[n - 1] += (Y - Saiphan[0, 0]) / Saiphan[0, 1];
}
if (i == 1)
{
continue;
}
if (i > 1)
{
double[] Xi = new double[i];
for (int j = 0; j < i; j++)
{
Xi[j] = j;
}
double[] Horner = HornerPn.Nhandathuc(Xi);
for (int j = 0; j < Horner.Length; j++)
{
Horner[j] = -Horner[j];
Horner[j] *= Saiphan[0, i] / (Saiphan[0, 1] * Giaithua);
Pn[j + k] += Horner[j];
}
Giaithua /= i;
k++;
}
}
for (int i = 0; i < n; i++)
{
if (Pn[i] < 0.0000001)
{
Pn[i] = Math.Round(Pn[i], 6);
}
}
return(Pn);
}
static double[] DaThucBessel(double[,] Saiphan)
{
int n = Saiphan.GetLength(0);
int k = 0;
int mid = (n - 1) / 2;
int a = 0, b = n - 1;
double Giaithua = 1;
double[] Pn = new double[n];
List <double> Heso = new List <double>();
for (int i = 2; i < n; i++)
{
Giaithua *= i;
}
for (double i = -mid + 1; i <= mid - 1; i++)
{
Heso.Add(i);
}
for (int i = n - 1; i >= 0; i--)
{
if (i == 0)
{
Pn[n - 1] += Saiphan[mid, mid];
}
if (i == 1)
{
Pn[n - 2] += (Saiphan[mid, mid + 1] + Saiphan[mid - 1, mid]) / 2;
}
if (i == 2)
{
Pn[n - 3] += Saiphan[mid - 1, mid + 1] / 2;
}
if (i > 2)
{
if (i % 2 == 0)
{
Heso.Add(0);
double[] Xi = Heso.ToArray();
double[] Horner = HornerPn.Nhandathuc(Xi);
for (int j = 0; j < Horner.Length; j++)
{
Horner[j] *= Saiphan[a, b] / Giaithua;
Pn[j + k] += Horner[j];
}
Heso.RemoveAt(Heso.Count - 1);
}
if (i % 2 != 0)
{
double[] Xi = Heso.ToArray();
double[] Horner = HornerPn.Nhandathuc(Xi);
a++;
b--;
for (int j = 0; j < Horner.Length; j++)
{
Horner[j] *= (Saiphan[a, b + 1] + Saiphan[a - 1, b]) / (2 * Giaithua);
Pn[j + k] += Horner[j];
}
Heso.RemoveAt(0);
Heso.RemoveAt(Heso.Count - 1);
}
Giaithua /= i;
k++;
}
}
return(Pn);
}
public static double [] Gauss_Tien_1(double [,] Saiphan)
{
int n = Saiphan.GetLength(0);
int k = 0;
int mid = (n - 1) / 2;
int a = 0, b = n;
double Giaithua = 1;
double[] Pn = new double[n];
List <double> Heso = new List <double>();
for (int i = 2; i < n; i++)
{
Giaithua *= i;
}
for (double i = -mid; i <= mid; i++)
{
Heso.Add(i);
}
for (int i = n - 1; i >= 0; i--)
{
if (i == 0)
{
Pn[n - 1] += Saiphan[mid, mid];
}
if (i == 1)
{
Pn[n - 2] += Saiphan[mid, mid + 1];
}
if (i > 1)
{
double[] Xi = new double[i];
if (i % 2 == 0)
{
b--;
Heso.RemoveAt(0);
}
if (i % 2 != 0)
{
a++;
Heso.RemoveAt(i);
}
for (int j = 0; j < i; j++)
{
Xi[j] = Heso[j];
}
double[] Horner = HornerPn.Nhandathuc(Xi);
for (int j = 0; j < Horner.Length; j++)
{
Horner[j] *= (Saiphan[a, b] / Giaithua);
Pn[j + k] += Horner[j];
}
Giaithua /= i;
k++;
}
}
return(Pn);
}