bessel(3M)                                                bessel(3M)


       NAME
             bessel: j0, j1, jn, y0, y1, yn - Bessel functions

       SYNOPSIS
             cc [flag ...] file ...  -lm [library ...]
             #include <math.h>
             double j0(double x);
             double j1(double x);
             double jn(int n, double x);
             double y0(double x);
             double y1(double x);
             double yn(int n, double x);

       DESCRIPTION
             j0 and j1 return Bessel functions of x of the first kind of
             orders 0 and 1, respectively.  jn returns the Bessel function
             of x of the first kind of order n.

             y0 and y1 return Bessel functions of x of the second kind of
             orders 0 and 1, respectively.  yn returns the Bessel function
             of x of the second kind of order n.  The value of x must be
             positive.

          Errors
             When x is zero, y0, y1, and yn return a value that will
             compare equal to -HUGE_VAL and set errno to EDOM.

             When x is negative, y0, y1, and yn return IEEE NaN on systems
             that support it, otherwise -HUGE_VAL, and set errno to EDOM.

             Arguments too large in magnitude cause all of these functions
             to return zero and to set errno to ERANGE.

             On systems that support IEEE NaN, if x is a quiet NaN, that
             value is returned.  If x is a signaling NaN, a quiet NaN is
             returned and the invalid operation exception is raised.  In
             either case, errno is set to EDOM.

             If the program was compiled with the -Xt compilation mode,
             non-positive arguments to y0, y1, and yn cause these functions
             to return a value that will compare equal to -HUGE and to set
             errno to EDOM.  In addition, a message indicating DOMAIN error
             is printed on the standard error output.  For arguments too
             large in magnitude, a message indicating TLOSS error is
             printed on the standard error output, in addition to the error
             behavior described above. These error handling procedures may


                           Copyright 1994 Novell, Inc.               Page 1

      bessel(3M)                                                bessel(3M)


            be changed with the function matherr.

      REFERENCES
            cc(1), matherr(3M)












































                          Copyright 1994 Novell, Inc.               Page 2