COPYSIGN
Section: Linux Programmer's Manual (3)
Updated: 2010-09-20
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.
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
copysign(),
copysignf(),
copysignl():
-
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
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.
RETURN VALUE
On success, these functions return a value whose magnitude is taken from
x
and whose sign is taken from
y.
If x is a NaN,
a NaN with the sign bit of y is returned.
ERRORS
No errors occur.
CONFORMING TO
C99, POSIX.1-2001.
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)
COLOPHON
This page is part of release 3.27 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
- COLOPHON
-
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Time: 07:35:35 GMT, March 26, 2013