/*      CubicSplineFastExample

        This example of the use of CubicSplineFast demonstrates
        interpolation within a data set of the refractive index of
        fused quartz tabulated as a function of wavelength.

        Michael T Flanagan

        5 January 2010 - modified version of CubicSplineExample (20 May 2002 - 4 February 2006)
*/

import flanagan.interpolation.*;

public class CubicSplineFastExample{

    public static void main(String arg[]){

        // Array of wavelengths (m)
        double[] wavelength = {185.0e-9, 214.0e-9, 275.0e-9, 361.0e-9, 509.0e-9, 589.0e-9, 656.0e-9};
        // Array of corresponding refractive indices
        double[] refrindex = {1.57464, 1.53386, 1.49634, 1.47503, 1.4619, 1.4583, 1.4564};
        // Interpolation variables
        double x1, y1;

        // Create a CubicSpline instance and initialise it to the data stored in the arrays wavelength and refrindex
        CubicSplineFast cs =new CubicSplineFast(wavelength, refrindex);

        // First interpolation at a wavelength of 250 nm
        //   also calculates the required derivatives
        x1 = 2.5e-7;
        y1=cs.interpolate(x1);
        System.out.println("The refractive index of fused quartz at " + x1*1.0e9 + " nm is "+ y1);

        // Second interpolation at a wavelength of 590 nm
        //  uses the derivatives calculated in the first call
        x1 = 5.9e-7;
        y1=cs.interpolate(x1);
        System.out.println("The refractive index of fused quartz at " + x1*1.0e9 + " nm is "+ y1);
    }
}