COPYSIGN(3)

NAME
copysign - changes the sign of x to that of y

SYNOPSIS
#include <math.h>
double
copysign(double x, double y);
long double
copysignl(long double x, long double y);
float
copysignf(float x, float y);

DESCRIPTION
The copysign() functions return x with its sign changed to y's.

SPECIAL VALUES
copysign(x, y) returns a NaN (with y's sign) if x is a NaN.

STANDARDS
The copysign() functions conform to ISO/IEC 9899:1999(E).