J0(3M) — UNIX Programmer’s Manual

NAME

j0, j1, jn, y0, y1, yn − bessel functions

#include <math.h>

double j0(x)
double x;

double j1(x)
double x;

double jn(n,x)
int n;
double x;

double y0(x)
double x;

double y1(x)
double x;

double yn(n,x)
int n;
double x;

These functions calculate Bessel functions of the first and second kinds for real arguments and integer orders.

On a VAX, negative arguments cause y0, y1 and yn to return the reserved operand and set errno to EDOM.