Example: The cubic spline interpolant

using System;
using Imsl.Math;

public class CsInterpolateEx1
{
	public static void  Main(String[] args)
	{
		int n = 11;
		double[] x = new double[n];
		double[] y = new double[n];
		
		for (int k = 0; k < n; k++)
		{
			x[k] = (double) k / (double) (n - 1);
			y[k] = System.Math.Sin(15.0 * x[k]);
		}
		
		CsInterpolate cs = new CsInterpolate(x, y);
		double csv = cs.Eval(0.25);
		Console.Out.WriteLine("The computed cubic spline value at " + 
                              "point .25 is " + csv);
	}
}

Output

The computed cubic spline value at point .25 is -0.548772503812158