Step::Basis Namespace Reference

Functions
double	Chebyshev (double x, int i)
double	Legendre (double x, int i)

Detailed Description

Bases for polynomials.

Function Documentation

Chebyshev()

double Step::Basis::Chebyshev	(	double	x,
		int	i
	)

Chebyshev of first kind.

    {
        if (std::abs(x) > 1) return 0.;
        switch (i) {
            case 0: return 1.;
            case 1: return x;
            default: return 2*x*Chebyshev(x, i-1)-Chebyshev(x, i-2);
        }
    }

Legendre()

double Step::Basis::Legendre	(	double	x,
		int	i
	)

Legendre.

    {
        if (std::abs(x) > 1) return 0.;
        switch (i) {
            case 0: return 1.;
            case 1: return x;
            default: return ( (2*i-1)*x*Legendre(x,i-1) - (i-1)*Legendre(x, i-2) )/i;
        }
    }