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COPYSIGN(3)                Linux Programmer's Manual               COPYSIGN(3)



NAME
       copysign, copysignf, copysignl - copy sign of a number

SYNOPSIS
       #include <math.h>

       double copysign(double x, double y);
       float copysignf(float x, float y);
       long double copysignl(long double x, long double y);

       Link with -lm.

DESCRIPTION
       The  copysign()  functions  return a value whose absolute value matches
       that of x, but whose sign matches that of y.  If x is a NaN, then a NaN
       with the sign of y is returned.

NOTES
       The copysign() functions may treat a negative zero as positive.

CONFORMING TO
       C99,  BSD  4.3.   This function is defined in(1,8) IEC 559 (and the appendix
       with recommended functions in(1,8) IEEE 754/IEEE 854).

SEE ALSO
       signbit(3)



GNU                               2002-08-10                       COPYSIGN(3)