#include <lcmath.h> double jn(int n, double x);
jn
computes the Bessel function of the first kind with order n
of
the value x
. The CPU time required to compute the Bessel function
increases with increasing values for n
. For very large values of
n
, the time can be quite large.
jn
returns the Bessel function of the first kind with order n
of
the argument x
, provided that this value is computable.
x
is too large (|x| >= 6.7465e9), jn
returns
0.0. In this case, a message indicating "total loss of significance" is also
written to stderr
(the standard error file).
If an error occurs in jn
, the _matherr
routine is called. You
supply your own version of _matherr
to suppress the diagnostic
message or modify the value returned.
jn
:
#include <stdio.h> #include <lcmath.h> main() { double y; y = jn(7, 5.); printf("jn(7, 5.) = %lfn", y); }
j0
, j1
, _matherr
, y0
, y1
, yn
Copyright (c) 1998 SAS Institute Inc. Cary, NC, USA. All rights reserved.