cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ] #include <mathcw.h> extern float inf (int n, float x); extern double in (int n, double x); extern long double inl (int n, long double x); extern __float80 inw (int n, __float80 x); extern __float128 inq (int n, __float128 x); extern long_long_double inll (int n, long_long_double x); extern decimal_float indf (int n, decimal_float x); extern decimal_double ind (int n, decimal_double x); extern decimal_long_double indl (int n, decimal_long_double x); extern decimal_long_long_double indll (int n, decimal_long_long_double x);
NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.
The modified 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).
The I(n,x) functions grow exponentially with increasing x, and overflow even with moderate x values. For that reason, there is a related family of functions that return values of this Bessel function reduced by a factor of exp(-x); see ins(3CW).