j0, j1, jn - Bessel functions of the first kind
#include <math.h> double j0(double x); double j1(double x); double jn(int n, double x);
The j0(), j1() and jn() functions compute Bessel functions of x of the first kind of orders 0, 1 and n respectively.
An application wishing to check for error situations should set errno to 0 before calling j0(), j1() or jn(). If errno is non-zero on return, or the return value is NaN, an error has occurred.
Upon successful completion, j0(), j1() and jn() return the relevant Bessel value of x of the first kind.
If the x argument is too large in magnitude, 0 is returned and errno may be set to [ERANGE].
If x is NaN, NaN is returned and errno may be set to [EDOM].
If the correct result would cause underflow, 0 is returned and errno may be set to [ERANGE].
The j0(), j1() and jn() functions may fail if:
- The value of x is NaN.
- The value of x was too large in magnitude, or underflow occurred.
No other errors will occur.
isnan(), y0(), <math.h>.
Derived from Issue 1 of the SVID.