jN
, jNf
, yN
, yNf
—Bessel functions#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);
Description
The Bessel functions are a family of functions that solve the
differential equation
2 2 2 x y'' + xy' + (x - p )y = 0
These functions have many applications in engineering and physics.
jn
calculates the Bessel function of the first kind of order
n. j0
and j1
are special cases for order 0 and order
1 respectively.
Similarly, yn
calculates the Bessel function of the second kind of
order n, and y0
and y1
are special cases for order 0 and
1.
jnf
, j0f
, j1f
, ynf
, y0f
, and y1f
perform the
same calculations, but on float
rather than double
values.
Returns
The value of each Bessel function at x is returned.
Portability
None of the Bessel functions are in ANSI C.