Computes the Bessel function.

#include <math.h>

double j0 (double x);

double j1 (double x);

double jn (int n, double x);

double y0 (double x);

double y1 (double x);

double yn (int n, double x);

Parameters

x

Value must be positive for y0, y1, and yn.

n

Integer order.

Remarks

These functions are commonly used in the mathematics of electromagnetic wave theory.

Return Values

j0, j1, and jn return the result of Bessel functions of the first kind: orders 0, 1, and n, respectively.

y0, y1, and yn return the result of Bessel functions of the second kind: orders 0, 1, and n, respectively. If x is negative, functions set errno to EDOM, print a DOMAIN error message to stderr, and return -HUGE_VAL.

These functions does not return standard ANSI domain or range errors.

Requirements

See Also

matherr, Mathematics reference books such as the Handbook of Mathematical Functions (Abramowitz and Stegun; Washington: U.S. Government Printing Office, 1964)