static void Main(string[] args)
{
double X0 = 15;
double X = 18;
double h = 5;
double[] Y = { 0.2588, 0.3420, 0.4226, 0.5, 0.5736, 0.6428, 0.7071 };
double[,] A = Saiphan(Y);
double[] B = Newton_Tien(A);
ExportData.ExportData1D(B);
ExportData.ExportData2D(A);
Console.WriteLine(HornerPn.Giatridathuc(B, (X - X0) / h));
}
static double[] Newton_Lui(double[,] Saiphan)
{
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] += Saiphan[n - 1, n - 1];
}
if (i == 1)
{
Pn[n - 2] += Saiphan[n - 2, n - 1];
}
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] *= (Saiphan[i, n - 1] / Giaithua);
Pn[j + k] += Horner[j];
}
Giaithua /= i;
k++;
}
}
return(Pn);
}