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 4.15 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/.
2017-09-15 J0(3)