J0(3)			   Linux Programmer's Manual			 J0(3)



NAME
       j0,  j0f,  j0l,	j1,  j1f,  j1l, jn, jnf, jnl - Bessel functions of the
       first kind

SYNOPSIS
       #include <math.h>

       double j0(double x);
       double j1(double x);
       double jn(int n, double x);

       float j0f(float x);
       float j1f(float x);
       float jnf(int n, float x);

       long double j0l(long double x);
       long double j1l(long double x);
       long double jnl(int n, long double x);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       j0(), j1(), jn():
	   _XOPEN_SOURCE
	       || /* Since glibc 2.19: */ _DEFAULT_SOURCE
	       || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
       j0f(), j0l(), j1f(), j1l(), jnf(), jnl():
	   _XOPEN_SOURCE  >= 600
	       || (_ISOC99_SOURCE && _XOPEN_SOURCE)
	       || /* Since glibc 2.19: */ _DEFAULT_SOURCE
	       || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE

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 j0f(), j1f(), and jnf(),  functions	are  versions  that  take  and
       return  float  values.	The j0l(), j1l(), and jnl() functions are ver-
       sions that take and return long double values.

RETURN VALUE
       On success, these functions return the appropriate Bessel value of  the
       first kind for x.

       If x is a NaN, a NaN is returned.

       If x is too large in magnitude, or the result underflows, a range error
       occurs, and the return value is 0.

ERRORS
       See math_error(7) for information on how to determine whether an	 error
       has occurred when calling these functions.

       The following errors can occur:

       Range error: result underflow, or x is too large in magnitude
	      errno is set to ERANGE.

       These functions do not raise exceptions for fetestexcept(3).

ATTRIBUTES
       For   an	  explanation	of   the  terms	 used  in  this	 section,  see
       attributes(7).

       +-------------------+---------------+---------+
       |Interface	   | Attribute	   | Value   |
       +-------------------+---------------+---------+
       |j0(), j0f(), j0l() | Thread safety | MT-Safe |
       +-------------------+---------------+---------+
       |j1(), j1f(), j1l() | Thread safety | MT-Safe |
       +-------------------+---------------+---------+
       |jn(), jnf(), jnl() | Thread safety | MT-Safe |
       +-------------------+---------------+---------+
CONFORMING TO
       The functions returning double conform to SVr4,	4.3BSD,	 POSIX.1-2001,
       and POSIX.1-2008.  The others are nonstandard functions that also exist
       on the BSDs.

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.

SEE ALSO
       y0(3)

COLOPHON
       This  page  is  part of release 4.10 of the Linux man-pages project.  A
       description of the project, information about reporting bugs,  and  the
       latest	  version     of     this    page,    can    be	   found    at
       https://www.kernel.org/doc/man-pages/.



				  2016-03-15				 J0(3)