HP-UX Floating-Point Guide

Appendix A 209
The C Math Library
C Math Library Tables
int isfinite(floating-type x); Returns a nonzero value just when
−infinity < x < +infinity; returns 0
otherwise (when |x| = infinity or x is
NaN).
int isgreater(floating-expr x,
floating-expr y);
Returns the value of (x > y).
int isgreaterequal(floating-expr x,
floating-expr y);
Returns the value of (x >= y).
int isinf(floating-type x); Returns a nonzero integer if x is an
infinity. Otherwise returns zero.
int isless(floating-expr x,
floating-expr y);
Returns the value of (x < y).
int islessequal(floating-expr x,
floating-expr y);
Returns the value of (x <= y).
int islessgreater(floating-expr x,
floating-expr y);
Returns the value of (x < y) || (x >
y).
int isnan(floating-type x); Returns a nonzero integer if x is NaN
(not-a-number). Otherwise returns zero.
int isnormal(floating-type x); Returns a nonzero integer if x is a
normalized value. Otherwise returns zero.
int isunordered(floating-expr x,
floating-expr y);
Returns 1 if its arguments are unordered
(that is, if either argument is a NaN) and
0 otherwise.
double j0(double x); Returns Bessel function of x of the first
kind of order 0.
double j1(double x); Returns Bessel function of x of the first
kind of order 1.
double jn(int n, double x); Returns Bessel function of x of the first
kind of order n.
double ldexp(double value, int exp); Returns value*(2**exp).
Function What It Does