1.\" $OpenBSD: fdim.3,v 1.2 2011/07/07 01:34:52 martynas Exp $ 2.\" 3.\" Copyright (c) 2004 David Schultz <das@FreeBSD.org> 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.\" $FreeBSD: src/lib/msun/man/fdim.3,v 1.1 2004/06/30 07:04:01 das Exp $ 28.\" 29.Dd $Mdocdate: July 7 2011 $ 30.Dt FDIM 3 31.Os 32.Sh NAME 33.Nm fdim , 34.Nm fdimf , 35.Nm fdiml 36.Nd positive difference functions 37.Sh SYNOPSIS 38.In math.h 39.Ft double 40.Fn fdim "double x" "double y" 41.Ft float 42.Fn fdimf "float x" "float y" 43.Ft long double 44.Fn fdiml "long double x" "long double y" 45.Sh DESCRIPTION 46The 47.Fn fdim , 48.Fn fdimf , 49and 50.Fn fdiml 51functions return the positive difference between 52.Fa x 53and 54.Fa y . 55That is, if 56.Fa x\- Ns Fa y 57is positive, then 58.Fa x\- Ns Fa y 59is returned. 60If either 61.Fa x 62or 63.Fa y 64is an \*(Na, then an \*(Na is returned. 65Otherwise, the result is 66.Li +0.0 . 67.Pp 68Overflow or underflow may occur if the exact result is not 69representable in the return type. 70No other exceptions are raised. 71.Sh SEE ALSO 72.Xr fabs 3 , 73.Xr fmax 3 , 74.Xr fmin 3 75.Sh STANDARDS 76The 77.Fn fdim , 78.Fn fdimf , 79and 80.Fn fdiml 81functions conform to 82.St -isoC-99 . 83.Sh HISTORY 84These routines first appeared in 85.Ox 4.5 . 86