public double FastCalculateSpline(double x)
{
double S = 0d;
if (x < grid.Left || x > grid.Right)
{
return(0); //если не лежит в отрезке то 0
}
int J = grid.Find(x);
int p = degree - 1;
int index = J - grid.BeginIndex;
if (Math.Abs(x - grid.Left) < EPS)
{
return(C[0]);
}
if (Math.Abs(x - grid.Right) < EPS)
{
return(C.Last);
}
Vector b = DeBoorMethods.bsplv(x, grid, degree, J);
for (int i = 0; i < degree && index + i < C.Length; i++)
{
S += C[index + i] * b[i];
}
return(S);
}
