J0 Section: Linux Programmer's Manual (3) Updated: June 26, 2025 Index   NAME j0, j1, jn, y0, y1, yn - Bessel functions   SYNOPSIS #include <math.h> double j0(double x); double j1(double x); double jn(int n, double x); double y0(double x); double y1(double x); double yn(int n, double x);   DESCRIPTION The j0() and j1() functions return Bessel functions of x of the first kind of orders 0 and 1, respectively. The jn() function returns the Bessel function of x of the first kind of order n. The y0() and y1() functions return Bessel functions of x of the second kind of orders 0 and 1, respectively. The yn() function returns the Bessel function of x of the second kind of order n. For the functions y0(), y1() and yn(), the value of x must be positive. For negative values of x, these functions return -HUGE_VAL.   CONFORMING TO SVID 3, BSD 4.3   BUGS There are errors of up to 2e-16 in the values returned by j0(), j1() and jn() for values of x between -8 and 8.   Index NAME SYNOPSIS DESCRIPTION CONFORMING TO BUGS This document was created by using the manual pages. Time: 11:58:07 GMT, March 24, 2025