DragonFly On-Line Manual Pages


J0(3)		      DragonFly 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 indepen- dent 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. DragonFly 3.7 February 18, 2008 DragonFly 3.7