cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ] #include <mathcw.h> extern void vyf (int n, float Y[/* n+1 */], float x); extern void vy (int n, double Y[/* n+1 */], double x); extern void vyl (int n, long double Y[/* n+1 */], long double x); extern void vyw (int n, __float80 Y[/* n+1 */], __float80 x); extern void vyq (int n, __float128 Y[/* n+1 */], __float128 x); extern void vyll (int n, long_long_double Y[/* n+1 */], long_long_double x); extern void vydf (int n, decimal_float Y[/* n+1 */], decimal_float x); extern void vyd (int n, decimal_double Y[/* n+1 */], decimal_double x); extern void vydl (int n, decimal_long_double decimal_long_double Y[/* n+1 */], decimal_long_double x); extern void vydll (int n, decimal_long_long_double decimal_long_long_double Y[/* n+1 */], decimal_long_long_double x);
NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.
This function is considerably faster than one that simply invokes yn(k,x) for each element.
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).
The algorithm may require internal storage for an array at least as big as Y[], but at least 4096 elements are guaranteed. Values for elements beyond that internal limit are set to quiet NaNs in the output array.
If the argument x is negative, errno is set to EDOM, and a quiet NaN is returned in the elements of the output array.
If the argument x 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 in the elements of the output array.