| .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
| .\" |
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| .\" permission notice identical to this one. |
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| .\" Since the Linux kernel and libraries are constantly changing, this |
| .\" manual page may be incorrect or out-of-date. The author(s) assume no |
| .\" responsibility for errors or omissions, or for damages resulting from |
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| .\" Formatted or processed versions of this manual, if unaccompanied by |
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| .\" References consulted: |
| .\" Linux libc source code |
| .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) |
| .\" 386BSD man pages |
| .\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu) |
| .\" Modified 2002-08-10 by Walter Harms (walter.harms@informatik.uni-oldenburg.de) |
| .TH COPYSIGN 3 2002-08-10 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| copysign, copysignf, copysignl \- copy sign of a number |
| .SH SYNOPSIS |
| .nf |
| .B #include <math.h> |
| .sp |
| .BI "double copysign(double " x ", double " y ); |
| .br |
| .BI "float copysignf(float " x ", float " y ); |
| .br |
| .BI "long double copysignl(long double " x ", long double " y ); |
| .fi |
| .sp |
| Link with \-lm. |
| .SH DESCRIPTION |
| The \fBcopysign\fP() functions return a value whose absolute value matches |
| that of \fIx\fP, but whose sign matches that of \fIy\fP. |
| If \fIx\fP is a NaN, then a NaN with the sign of \fIy\fP is returned. |
| .SH NOTES |
| The \fBcopysign\fP() functions may treat a negative zero as positive. |
| .SH "CONFORMING TO" |
| C99, 4.3BSD. |
| This function is defined in IEC 559 (and the appendix with |
| recommended functions in IEEE 754/IEEE 854). |
| .SH "SEE ALSO" |
| .BR signbit (3) |