HP-UX Reference (11i v1 05/09) - 3 Library Functions N-Z (vol 7)

y0(3M) y0(3M)

NAME

y0(), y1( ), yn() - Bessel functions of the second kind

SYNOPSIS

#include <math.h>

double y0(double x);

double y1(double x);

double yn(int n, double x);

DESCRIPTION

y0() and y1() return the Bessel functions of x of the second kind of orders 0 and 1 respectively.

yn()

returns the Bessel function of x of the second kind of order n. The value of x must be greater than zero.

To use these functions, compile either with the default

-Ae option or with the -Aa and

-D_HPUX_SOURCE

options. Make sure your program includes <math.h>. Link in the math library by

specifying

-lm on the compiler or linker command line.

RETURN VALUE

If x is negative or zero, y0(), y1(), and yn() return −HUGE_VAL.

If x is NaN,

y0(), y1(), and yn() return NaN.

If the correct result after rounding would be smaller in magnitude than MINDOUBLE, y0(),

y1(), and

yn() return zero.

If the correct result would overﬂow, y0(), y1(), and yn() return −HUGE_VAL

ERRORS

No errors are deﬁned.