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| yn |
| Portability: | UNIX compatible |
| SYNOPSIS | |
| DESCRIPTION | |
| RETURN VALUE | |
| DIAGNOSTICS | |
| EXAMPLE | |
| RELATED FUNCTIONS | |
| SEE ALSO |
| SYNOPSIS |
#include <lcmath.h> double yn(int n, double x);
| DESCRIPTION |
yn
computes the order
n
Bessel function of
the second kind 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.
| RETURN VALUE |
yn
returns the order
n
Bessel function of
the second kind of the argument
x
, provided
that this value is computable.
| DIAGNOSTICS |
If the value of
x
is 0.0, a diagnostic message is written to the standard error file
(
stderr
) and the function returns
-HUGE_VAL
, the largest negative floating-point
number that can be represented.
If the magnitude of
x
is too large (|x| > = 6.7465e9),
yn
returns
0.0. In this case, the message "total loss of significance" is written to
stderr
.
If the magnitude of
x
is too close to 0, an overflow error occurs during computation of
yn
. The limiting value for
x
depends
on the value for
n
. If
n
is 1, the limiting value is approximately 8.032e-77. The limiting
value increases with increasing values of
n
.
When
x
is too small, a diagnostic message
is written to
stderr
, and
yn
returns
-HUGE_VAL
.
If an error occurs in
yn
, the
_matherr
routine is called.
You can supply your own version of
_matherr
to suppress the diagnostic message or modify the value returned.
| EXAMPLE |
This example computes the Bessel function of the second kind, of order 7 at x = 5:
#include <stdio.h>
#include <lcmath.h
main()
{
double y;
y = y1(5.);
printf("y1(5.) = %lf\n", y);
}
| RELATED FUNCTIONS |
j0
,
j1
,
jn
,
_matherr
,
y0
,
y1
| SEE ALSO |
|
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Copyright © 2001 by SAS Institute Inc., Cary, NC, USA. All rights reserved.