/* This file contains the functions to calculate Gegenbauer polynomials. */

#include <gegenbauer.h>

/* gegenbauer_1p5(n, x) calculates the Gegenbauer polynomials C^3/2_n(x) */

double gegenbauer_1p5(int n, double x)
{
     switch(n)
     {
     case 0 : 
            {
             return 1.;
             break;
            }
     case 1 : 
            {
             return 3. * x;
             break;
            }
     case 2 : 
            {
             return 3./2. * (-1. + 5. * pow(x,2.));
             break;
            }
     case 3 : 
            {
             return 5./2. * (-3. * x + 7. * pow(x,3.));
             break;
            }
     case 4 : 
            {
             return 15./8. * (1. - 14. * pow(x,2.) + 21. * pow(x,4.));
             break;
            }
     case 5 : 
            {
             return 7./8. * (15. * x - 90. * pow(x,3.) + 99. * pow(x,5.));
             break;
            }
     }
}


double norm_gegenbauer_1p5(int n, int m, double x)
{
     return (1 - pow(x,2.)) * gegenbauer_1p5(n, x) * gegenbauer_1p5(m, x);
}