HP-UX Floating-Point Guide

Appendix A 213
The C Math Library
C Math Library Tables
double trunc(double x); Returns x truncated to the integer-valued
double-precision number nearest to but no
larger in magnitude than x.
double y0(double x); Returns Bessel function of x of the second
kind of order 0.
double y1(double x); Returns Bessel function of x of the second
kind of order 1.
double yn(int n, double x); Returns Bessel function of x of the second
kind of order n.
Function What It Does