c99 [ flag... ] file... -lm [ library... ] #include <math.h>
double y0(double x);
float y0f(float x);
long double y0l(long double x);
double y1(double x);
float y1f(float x);
long double y1l(long double x);
double yn(int n, double x);
float ynf(int n, float x);
long double ynl(int n, long double x);
These functions compute Bessel functions of x of the second kind of orders 0, 1 and n, respectively.
Upon successful completion, these functions return the relevant Bessel value of x of the second kind.
If x is NaN, a NaN is returned.
If x is negative, -HUGE_VAL or NaN is returned.
If x is 0.0, -HUGE_VAL is returned.
If the correct result would cause overflow, -HUGE_VAL is returned.
For exceptional cases, matherr(3M) tabulates the values to be returned as specified by SVID3 and XPG3.
An application wanting to check for exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception has been raised. An application should either examine the return value or check the floating point exception flags to detect exceptions.
See attributes(5) for descriptions of the following attributes:
ATTRIBUTE TYPE | ATTRIBUTE VALUE |
Interface Stability | See below. |
MT-Level | MT-Safe |
The y0(), y1(), and yn() functions are Standard. The y0f(), y0l(), y1f(), y1l(), ynf(), and ynl() functions are Stable.
isnan(3M), feclearexcept(3M), fetestexcept(3M), j0(3M), math.h(3HEAD), matherr(3M), attributes(5), standards(5)