26 Numerics library [numerics]

26.9 Mathematical functions for floating-point types [c.math]

26.9.5 Mathematical special functions [sf.cmath]

26.9.5.19 Spherical Bessel functions (of the first kind) [sf.cmath.sph_bessel]

double sph_bessel(unsigned n, double x); float sph_besself(unsigned n, float x); long double sph_bessell(unsigned n, long double x);

Effects: These functions compute the spherical Bessel functions of the first kind of their respective arguments n and x.

Returns: jn(x) = (π/2x)1/2 Jn + 1/2(x),    for x ≥ 0 where n is n and x is x.

Remarks: The effect of calling each of these functions is implementation-defined if n >= 128.