1.\" Copyright (c) 2004 David Schultz <das@FreeBSD.org> 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.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD: src/lib/msun/man/fdim.3,v 1.1 2004/06/30 07:04:01 das Exp $ 26.\" $NetBSD: fdim.3,v 1.3 2010/03/08 02:35:50 snj Exp $ 27.\" 28.Dd June 29, 2004 29.Dt FDIM 3 30.Os 31.Sh NAME 32.Nm fdim , 33.Nm fdimf , 34.Nm fdiml 35.Nd positive difference functions 36.Sh LIBRARY 37.Lb libm 38.Sh SYNOPSIS 39.In math.h 40.Ft double 41.Fn fdim "double x" "double y" 42.Ft float 43.Fn fdimf "float x" "float y" 44.Ft long double 45.Fn fdiml "long double x" "long double y" 46.Sh DESCRIPTION 47The 48.Fn fdim , 49.Fn fdimf , 50and 51.Fn fdiml 52functions return the positive difference between 53.Fa x 54and 55.Fa y . 56That is, if 57.Fa x\- Ns Fa y 58is positive, then 59.Fa x\- Ns Fa y 60is returned. 61If either 62.Fa x 63or 64.Fa y 65is an \*(Na, then an \*(Na is returned. 66Otherwise, the result is 67.Li +0.0 . 68.Pp 69Overflow or underflow may occur iff the exact result is not 70representable in the return type. 71No other exceptions are raised. 72.Sh SEE ALSO 73.Xr fabs 3 , 74.Xr fmax 3 , 75.Xr fmin 3 , 76.Xr math 3 77.Sh STANDARDS 78The 79.Fn fdim , 80.Fn fdimf , 81and 82.Fn fdiml 83functions conform to 84.St -isoC-99 . 85.Sh HISTORY 86These routines first appeared in 87.Fx 5.3 88and 89.Nx 5.1 . 90