|J0(3)||Linux Programmer's Manual||J0(3)|
NAME¶j0, j0f, j0l, j1, j1f, j1l, jn, jnf, jnl - Bessel functions of the first kind
#include <math.h>double j0(double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
j0(), j1(), jn():
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 600
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 versions 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.
CONFORMING TO¶The functions returning double conform to SVr4, 4.3BSD, POSIX.1-2001. 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.
COLOPHON¶This page is part of release 3.74 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 http://www.kernel.org/doc/man-pages/.