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copysign
Langue: en
Version: 2007-07-26 (fedora - 25/11/07)
Section: 3 (Bibliothèques de fonctions)
NAME
copysign, copysignf, copysignl - copy sign of a numberSYNOPSIS
#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.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
copysign(), copysignf(), copysignl(): _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99
DESCRIPTION
The copysign() functions return a value whose absolute value matches that of x, but whose sign bit matches that of y. If x is a NaN, then a NaN with the sign bit of y is returned.CONFORMING TO
C99, 4.3BSD. This function is defined in IEC 559 (and the appendix with recommended functions in IEEE 754/IEEE 854).NOTES
On architectures where the floating-point formats are not IEEE 754 compliant, the copysign() functions may treat a negative zero as positive.SEE ALSO
signbit(3)Contenus ©2006-2024 Benjamin Poulain
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