Example: The B-spline least squares fit

A B-Spline least squares fit to data is computed. The value of the spline at point 4.5 is printed.
using System;
using Imsl.Math;

public class BsLeastSquaresEx1
{
    public static void  Main(String[] args)
    {
        double[] x = new double[]{0, 1, 2, 3, 4, 5, 8, 9, 10};
        double[] y = new double[]{1.0, 0.8, 2.4, 3.1, 4.5, 
                                     5.8, 6.2, 4.9, 3.7};
        
        BsLeastSquares bs = new BsLeastSquares(x, y, 5);
        double bsv = bs.Eval(4.5);
        Console.Out.WriteLine("The computed B-spline value at point " +
                              "4.5 is " + bsv);
    }
}

Output

The computed B-spline value at point 4.5 is 5.22855432359694

Link to C# source.