1.\" Copyright (c) 1985, 1991 Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)ieee.3 6.4 (Berkeley) 5/6/91 33.\" $FreeBSD$ 34.\" 35.Dd January 26, 2005 36.Dt COPYSIGN 3 37.Os 38.Sh NAME 39.Nm copysign , 40.Nm copysignf , 41.Nm copysignl 42.Nd copy sign 43.Sh LIBRARY 44.Lb libm 45.Sh SYNOPSIS 46.In math.h 47.Ft double 48.Fn copysign "double x" "double y" 49.Ft float 50.Fn copysignf "float x" "float y" 51.Ft long double 52.Fn copysignl "long double x" "long double y" 53.Sh DESCRIPTION 54The 55.Fn copysign , 56.Fn copysignf 57and 58.Fn copysignl 59functions 60return 61.Fa x 62with its sign changed to 63.Fa y Ns 's . 64.Sh SEE ALSO 65.Xr fabs 3 , 66.Xr fdim 3 , 67.Xr ieee 3 , 68.Xr math 3 69.Sh STANDARDS 70The 71.Fn copysign , 72.Fn copysignf , 73and 74.Fn copysignl 75routines conform to 76.St -isoC-99 . 77They implement the Copysign function recommended by 78.St -ieee754 . 79.Sh HISTORY 80The 81.Fn copysign , 82.Fn copysignf , 83and 84.Fn copysignl 85functions appeared in 86.Bx 4.3 , 87.Fx 2.0 , 88and 89.Fx 5.3 , 90respectively. 91