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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():
           _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE
       j0f(), j0l(), j1f(), j1l(), jnf(), jnl():
           _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() etc. and j0l() etc. functions  are  versions  that  take  and
       return float and long double values, respectively.
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).
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.
SEE ALSO
       y0(3)
COLOPHON
       This page is part of release 3.53 of the Linux  man-pages  project.   A
       description  of  the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

                                  2010-09-20                             J0(3)