NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | BUGS | SEE ALSO | COLOPHON

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

NAME         top

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

SYNOPSIS         top

       #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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       y0(3)

COLOPHON         top

       This page is part of release 4.08 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)