bessel(3)						     Library Functions Manual							 bessel(3)

NAME

       bessel, j0, j1, jn, y0, y1, yn - Compute Bessel functions

LIBRARY

       Math Library (libm.a)

SYNOPSIS

       #include <math.h>

       double  j0   (double  x); float	j0f (float  x); long double j0l (long double x); double j1  (double x); float  j1f (float  x); long double
       j1l (long double x); double jn  (int n, double x); float  jnf (int n, float  x); long double jnl  (int n, long double x); double y0   (dou-
       ble  x); float  y0f (float  x); long double y0l (long double x); double y1  (double x); float  y1f (float  x); long double y1l (long double
       x); double yn  (int n, double x); float	ynf   (int n, float  x); long double ynl  (int n, long double x);

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       j0():  XPG4

       j1():  XPG4

       jn():  XPG4

       y0():  XPG4

       y1():  XPG4

       yn():  XPG4

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

DESCRIPTION

       The j0(), j0f(), j0l(), j1(), j1f(), and j1l() functions return the value of the Bessel function of the first kind of orders 0  (zero)  and
       1, respectively.

       The jn(), jnf(), and jnl() functions return the value of the Bessel function of the first kind of order n.

       The y0(), y0f(), y0l(), y1(), y1f(), and y1l() functions return the value of the Bessel functions of the second kind of orders 0 (zero) and
       1, respectively.

       The yn(), ynf(), and ynl()  functions return the value of the Bessel function of the second kind of order n.

       The following table describes function behavior in response to exceptional arguments:

       --------------------------------------------------------------
       Function 	     Exceptional Argument   Routine Behavior
       --------------------------------------------------------------
       j0(), j1(), jn()      None		    N/A
       j0f(), j1f(), jnf()   None		    N/A
       j0l(), j1l(), jnl()   None		    N/A
       y0(), y1(), yn()      x < 0		    Invalid argument
       y0f(), y1f(), ynf()   x < 0		    Invalid argument
       y0l(), y1l(), ynl()   x < 0		    Invalid argument
       y0(), y1(), yn()      x = 0		    Overflow
       y0f(), y1f(), ynf()   x = 0		    Overflow
       y0l(), y1l(), ynl()   x = 0		    Overflow
       --------------------------------------------------------------

       The j1() and jn() functions can result in an underflow as x gets small.	The largest value of x for which this occurs is a function of n.

       The y1() and yn() functions can result in an overflow as x gets small.  The largest value of x for which this occurs is a function of n.

       delim off

																	 bessel(3)