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copysign(3) [v7 man page]

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

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(): _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE DESCRIPTION
These functions return a value whose absolute value matches that of x, but whose sign bit matches that of y. For example, copysign(42.0, -1.0) and copysign(-42.0, -1.0) both return -42.0. 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. ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7). +-------------------------------------+---------------+---------+ |Interface | Attribute | Value | +-------------------------------------+---------------+---------+ |copysign(), copysignf(), copysignl() | Thread safety | MT-Safe | +-------------------------------------+---------------+---------+ CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008. 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, these functions may treat a negative zero as positive. SEE ALSO
signbit(3) COLOPHON
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2017-09-15 COPYSIGN(3)

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COPYSIGN(3P)						     POSIX Programmer's Manual						      COPYSIGN(3P)

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond- ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. NAME
copysign, copysignf, copysignl -- number manipulation function 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); DESCRIPTION
The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2008 defers to the ISO C standard. These functions shall produce a value with the magnitude of x and the sign of y. On implementations that represent a signed zero but do not treat negative zero consistently in arithmetic operations, these functions regard the sign of zero as positive. RETURN VALUE
Upon successful completion, these functions shall return a value with the magnitude of x and the sign of y. ERRORS
No errors are defined. The following sections are informative. EXAMPLES
signbit() The Base Definitions volume of POSIX.1-2008, <math.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Stan- dard is the referee document. The original Standard can be obtained online at . Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see . IEEE
/The Open Group 2013 COPYSIGN(3P)
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