cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ] #include <mathcw.h> extern float ynf (int n, float x); extern double yn (int n, double x); extern long double ynl (int n, long double x); extern __float80 ynw (int n, __float80 x); extern __float128 ynq (int n, __float128 x); extern long_long_double ynll (int n, long_long_double x); extern decimal_float yndf (int n, decimal_float x); extern decimal_double ynd (int n, decimal_double x); extern decimal_long_double yndl (int n, decimal_long_double x); extern decimal_long_long_double yndll (int n, decimal_long_long_double x);
NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.
In some fields, particularly in the physics literature, this function is called the Neumann function, and denoted N(n,x).
This function is not required by ISO Standard C (1989 or 1999), but it is part of IEEE Std 1003.1-2001, informally known as POSIX 2001. Implementations of this function are also available in most Unix C math libraries (-lm).
The ordinary Bessel functions provided by these software implementations are defined according to Chapter 9, Bessel Functions of Integer Order, of the Handbook of Mathematical Functions, edited by Milton Abramowitz and Irene A. Stegun, National Bureau of Standards Applied Mathematics Series #55, US Department of Commerce, Washington, DC (1964).
If the argument is negative, errno is set to EDOM, and a quiet NaN is returned.
If the argument is zero, errno is set to ERANGE, and a negative Infinity (or the negative of the largest floating-point magnitude, if Infinity is not available) is returned.