J0(3) Library Functions Manual J0(3)

j0, j1, jn, y0, y1, ynbessel functions of first and second kind

#include <math.h>

double
j0(double x);

float
j0f(float x);

double
j1(double x);

float
j1f(float x);

double
jn(int n, double x);

float
jnf(int n, float x);

double
y0(double x);

float
y0f(float x);

double
y1(double x);

float
y1f(float x);

double
yn(int n, double x);

float
ynf(int n, float x);

The functions (x) and j1(x) compute the Bessel function of the first kind of the order 0 and the order 1, respectively; the function (n, x) computes the Bessel function of the first kind of the integer order n.

The functions (x) and (x) compute the linearly independent Bessel function of the second kind of the order 0 and the order 1, respectively, for the positive integer value x (expressed as a double); the function (n, x) computes the Bessel function of the second kind for the integer order n for the positive integer value x (expressed as a double).

j0(0) returns 1.

(±infinity) returns 0.

(NaN) returns a NaN.

(0) returns 0.

(+infinity) returns 0.

(NaN) returns a NaN.

(0) , (0) , and (n, 0) all return -infinity and raise the "division-by-zero" floating-point flag.

December 11, 2006 BSD 4