DOKK / manpages / debian 11 / manpages-pt-dev / j0.3.pt
J0(3) Linux Programmer's Manual J0(3)

j0, j1, jn, y0, y1, yn - Bessel functions

#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);

The j0() and j1() functions return Bessel functions of x of the first kind of orders 0 and 1, respectively. The jn() function returns the Bessel function of x of the first kind of order n.

The y0() and y1() functions return Bessel functions of x of the second kind of orders 0 and 1, respectively. The yn() function returns the Bessel function of x of the second kind of order n.

For the functions y0(), y1() and yn(), the value of x must be positive. For negative values of x, these functions return -HUGE_VAL.

SVID 3, BSD 4.3

There are errors of up to 2e-16 in the values returned by j0(), j1() and jn() for values of x between -8 and 8.

June 26, 1993