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j0l(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
   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.

   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 4.09 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)



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