#include <lcmath.h> double y1(double x);
y1
computes the order 1 Bessel function of the second kind of the
value x
.
y1
returns the order 1 Bessel function of the second kind of the
argument x
, provided that this value is computable.
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), y1
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 (|x| < approximately 8.032e-77),
an overflow error occurs during computation of y1
. In this case, a
diagnostic message is written to stderr
, and y1
returns
-HUGE_VAL
.
If an error occurs in y1
, the _matherr
routine is called.
You can supply your own version of _matherr
to suppress the diagnostic
message or modify the value returned.
#include <stdio.h> #include <lcmath.h> main() { double y; y = y1(5.); printf("y1(5.) = %lfn", y); }
j0
, j1
, jn
, _matherr
, y0
, yn
Copyright (c) 1998 SAS Institute Inc. Cary, NC, USA. All rights reserved.