J0(3) BSD Library Functions Manual J0(3)
NAME
j0, j0f, j1, j1f, jn, jnf, y0, y0f, y1, y1f, yn, ynf -- Bessel functions of first and second kind
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#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 functions j0(), j0f(), j1() and j1f() compute the Bessel function of the first kind of the order 0 and the order 1, respectively, for the
real value x; the functions jn() and jnf() compute the Bessel function of the first kind of the integer order n for the real value x.
The functions y0(), y0f(), y1(), and y1f() compute the linearly independent Bessel function of the second kind of the order 0 and the order
1, respectively, for the positive real value x; the functions yn() and ynf() compute the Bessel function of the second kind for the integer
order n for the positive real value x.
RETURN VALUES
These routines return values of their respective Bessel functions. For large positive inputs, they may underflow and return +-0.
The following applies to y0(), y0f(), y1(), y1f(), yn(), and ynf(). If x is negative, these routines will generate an invalid exception and
return NaN. If x is 0 or a sufficiently small positive number, these routines will generate an overflow exception and return -infinity.
SEE ALSO
math(3)
STANDARDS
The j0(), j1(), jn(), y0(), y1(), and yn() functions conform to IEEE Std 1003.1-2001 (``POSIX.1''). The float versions are extensions.
HISTORY
This set of functions appeared in Version 7 AT&T UNIX.
BSD
February 18, 2008 BSD
