y1 (3)
NAME
y0, y0f, y0l, y1, y1f, y1l, yn, ynf, ynl - Bessel functions of the second kindSYNOPSIS
#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)):
y0(), y1(), yn():
_XOPEN_SOURCE
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
_XOPEN_SOURCE >= 600
|| (_ISOC99_SOURCE && _XOPEN_SOURCE)
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
|| (_ISOC99_SOURCE && _XOPEN_SOURCE)
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
DESCRIPTION
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.RETURN VALUE
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.)ERRORS
See math_error(7) for information on how to determine whether an error has occurred when calling these functions. The following errors can occur:- Domain error: x is negative
- errno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.
- Pole error: x is 0.0
- errno is set to ERANGE (but see BUGS). No FE_DIVBYZERO exception is returned by fetestexcept(3) for this case.
- Range error: result underflow
- errno is set to ERANGE. No FE_UNDERFLOW exception is returned by fetestexcept(3) for this case.
- Range error: result overflow
- errno is not set for this case. An overflow floating-point exception (FE_OVERFLOW) is raised.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).Interface | Attribute | Value |
y0 (), y0f (), y0l () | Thread safety | MT-Safe |
y1 (), y1f (), y1l () | Thread safety | MT-Safe |
yn (), ynf (), ynl () | Thread safety | MT-Safe |