BESSEL(3M-SVR4)     RISC/os Reference Manual      BESSEL(3M-SVR4)



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 func-
     tion 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 func-
     tion 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 mes-
     sage 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 out-
     put.

     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,
     HUGE_VAL is returned instead of HUGE and no error messages
     are printed.






                        Printed 11/19/92                   Page 1