bessel(3M)                   (Math Libraries)                    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.

   SEE ALSO
         matherr(3M).

   DIAGNOSTICS
         Non-positive arguments cause y0, y1, and yn to return the value -HUGE
         and to set errno to EDOM.  In addition, a message indicating DOMAIN
         error is printed on the standard error output.

         Arguments too large in magnitude cause j0, j1, y0, and y1 to return 0
         and to set errno to ERANGE.  In addition, a message indicating TLOSS
         error is printed on the standard error output.

         Except when the -Xc compilation option is used, these error-handling
         procedures may be changed with the function matherr.  When the -Xa or
         -Xc compilation options are used, HUGEVAL is returned instead of
         HUGE and no error messages are printed.








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