Compute a Bessel function of the first kind of order 1
#include <math.h> double j1( double x ); float j1f( float x );
These functions compute the Bessel function for x of the first kind of order 1.
To check for error situations, use feclearexcept() and fetestexcept(). For example:
The Bessel value of x of the first kind of order 1.
If: | These functions return: | Errors: |
---|---|---|
x is ±0.0 | 0.0, with the same sign as x | — |
x is ±Inf | 0.0, with the same sign as x | — |
x is NaN | NaNNaN | — |
The correct result would cause underflow | 0.0 | FE_UNDERFLOW |
These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.
j1() is POSIX 1003.1 XSI; j1f() is Unix
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | No |
Signal handler | No |
Thread | Yes |