BESSEL(3M)          UNIX Programmer's Manual           BESSEL(3M)

NAME
     j0, j1, jn, y0, y1, yn - bessel functions

SYNOPSIS
     #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;

HP-UX COMPATIBILITY
     Level:    HP-UX/RUN ONLY

     Origin:   System III

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

DIAGNOSTICS
     Negative arguments cause _y_0, _y_1, and _y_n to return the  value
     of HUGE (defined in _m_a_t_h._h), and sets _e_r_r_n_o to EDOM.