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.Dd June 29, 2004 26.Dt FDIM 3 27.Os 28.Sh NAME 29.Nm fdim , 30.Nm fdimf , 31.Nm fdiml 32.Nd positive difference functions 33.Sh LIBRARY 34.Lb libm 35.Sh SYNOPSIS 36.In math.h 37.Ft double 38.Fn fdim "double x" "double y" 39.Ft float 40.Fn fdimf "float x" "float y" 41.Ft long double 42.Fn fdiml "long double x" "long double y" 43.Sh DESCRIPTION 44The 45.Fn fdim , 46.Fn fdimf , 47and 48.Fn fdiml 49functions return the positive difference between 50.Fa x 51and 52.Fa y . 53That is, if 54.Fa x\- Ns Fa y 55is positive, then 56.Fa x\- Ns Fa y 57is returned. 58If either 59.Fa x 60or 61.Fa y 62is an \*(Na, then an \*(Na is returned. 63Otherwise, the result is 64.Li +0.0 . 65.Pp 66Overflow or underflow may occur if the exact result is not 67representable in the return type. 68No other exceptions are raised. 69.Sh SEE ALSO 70.Xr fabs 3 , 71.Xr fmax 3 , 72.Xr fmin 3 , 73.Xr math 3 74.Sh STANDARDS 75The 76.Fn fdim , 77.Fn fdimf , 78and 79.Fn fdiml 80functions conform to 81.St -isoC-99 . 82.Sh HISTORY 83These routines first appeared in 84.Fx 5.3 . 85