y0, y0f, y0l, y1, y1f, y1l, yn, ynf, ynl - Bessel functions of the second kind
#include <math.h>
double y0(double x);
double y1(double x);
double yn(int n, double x);
float y0f(float x);
float y1f(float x);
float ynf(int n, float x);
long double y0l(long double x);
long double y1l(long double x);
long double ynl(int n, long double x);
Link with -lm
.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_XOPEN_SOURCE || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
y0f(), y0l(), y1f(), y1l(), ynf(), ynl():
_XOPEN_SOURCE >= 600 || (_ISOC99_SOURCE && _XOPEN_SOURCE) || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
The y0() and y1() functions return Bessel functions of x
of the second kind of orders 0 and 1, respectively. The yn() function returns the Bessel function of x
of the second kind of order n
.
The value of x
must be positive.
The y0f(), y1f(), and ynf() functions are versions that take and return float
values. The y0l(), y1l(), and ynl() functions are versions that take and return long double
values.
On success, these functions return the appropriate Bessel value of the second kind for x
.
If x
is a NaN, a NaN is returned.
If x
is negative, a domain error occurs, and the functions return -HUGE_VAL, -HUGE_VALF, or -HUGE_VALL, respectively. (POSIX.1-2001 also allows a NaN return for this case.)
If x
is 0.0, a pole error occurs, and the functions return -HUGE_VAL, -HUGE_VALF, or -HUGE_VALL, respectively.
If the result underflows, a range error occurs, and the functions return 0.0
If the result overflows, a range error occurs, and the functions return -HUGE_VAL, -HUGE_VALF, or -HUGE_VALL, respectively. (POSIX.1-2001 also allows a 0.0 return for this case.)
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
x
is negativeerrno
is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.
x
is 0.0errno
is set to ERANGE (but see BUGS). No FE_DIVBYZERO exception is returned by fetestexcept(3) for this case.
errno
is set to ERANGE. No FE_UNDERFLOW exception is returned by fetestexcept(3) for this case.
errno
is not set for this case. An overflow floating-point exception (FE_OVERFLOW) is raised.
The functions returning double
conform to SVr4, 4.3BSD, POSIX.1-2001, POSIX.1-2008. The others are nonstandard functions that also exist on the BSDs.
On a pole error, these functions set errno
to EDOM, instead of ERANGE as POSIX.1-2004 requires.
In glibc version 2.3.2 and earlier, these functions do not raise an invalid floating-point exception (FE_INVALID) when a domain error occurs.
j0(3)
This page is part of release 4.15 of the Linux man-pages
project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.