Originální popis anglicky:
y0, y1, yn - Bessel functions of the second kind
Návod, kniha: POSIX Programmer's Manual
#include <math.h>
double y0(double
x);
double y1(double
x);
double yn(int
n, double x);
The
y0(),
y1(), and
yn() functions shall compute Bessel
functions of
x of the second kind of orders 0, 1, and
n,
respectively.
An application wishing to check for error situations should set
errno to
zero and call
feclearexcept(FE_ALL_EXCEPT) before calling these
functions. On return, if
errno is non-zero or
fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is
non-zero, an error has occurred.
Upon successful completion, these functions shall return the relevant Bessel
value of
x of the second kind.
If
x is NaN, NaN shall be returned.
If the
x argument to these functions is negative, -HUGE_VAL or NaN shall
be returned, and a domain error may occur.
If
x is 0.0, -HUGE_VAL shall be returned and a range error may occur.
If the correct result would cause underflow, 0.0 shall be returned and a range
error may occur.
If the correct result would cause overflow, -HUGE_VAL or 0.0 shall be returned
and a range error may occur.
These functions may fail if:
- Domain Error
- The value of x is negative.
If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then
errno shall be set to [EDOM]. If the integer expression
(math_errhandling & MATH_ERREXCEPT) is non-zero, then the invalid
floating-point exception shall be raised.
- Range Error
- The value of x is 0.0, or the correct result would
cause overflow.
If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then
errno shall be set to [ERANGE]. If the integer expression
(math_errhandling & MATH_ERREXCEPT) is non-zero, then the overflow
floating-point exception shall be raised.
- Range Error
- The value of x is too large in magnitude, or the
correct result would cause underflow.
If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then
errno shall be set to [ERANGE]. If the integer expression
(math_errhandling & MATH_ERREXCEPT) is non-zero, then the underflow
floating-point exception shall be raised.
The following sections are informative.
None.
On error, the expressions (math_errhandling & MATH_ERRNO) and
(math_errhandling & MATH_ERREXCEPT) are independent of each other, but at
least one of them must be non-zero.
None.
None.
feclearexcept() ,
fetestexcept() ,
isnan() ,
j0() ,
the Base Definitions volume of IEEE Std 1003.1-2001, Section
4.18, Treatment of Error Conditions for Mathematical Functions,
<math.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
