Section: Linux Programmer's Manual (3) Updated: 2010-09-20 Local index
copysign, copysignf, copysignl - copy sign of a number
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
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
functions return a value whose absolute value matches
that of x, but whose sign bit matches that of y.
On success, these functions return a value whose magnitude is taken from
and whose sign is taken from
If x is a NaN,
a NaN with the sign bit of y is returned.
No errors occur.
This function is defined in IEC 559 (and the appendix with
recommended functions in IEEE 754/IEEE 854).
On architectures where the floating-point formats are not IEEE 754 compliant,
functions may treat a negative zero as positive.
This page is part of release 3.27 of the Linux
A description of the project,
and information about reporting bugs,
can be found at
- RETURN VALUE
- CONFORMING TO
- SEE ALSO
This document was created by
using the manual pages.
Time: 21:43:46 GMT, April 16, 2011