.\" Copyright (c) 1985, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgement:
.\" This product includes software developed by the University of
.\" California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" from: @(#)floor.3 6.5 (Berkeley) 4/19/91
.\" $Id: modf.3,v 1.4 2004/12/20 21:35:46 scp Exp $
.\"
.Dd July 24, 2003
.Dt MODF 3
.Os
.Sh NAME
.Nm modf
.Nd return integral and fractional parts
.Sh SYNOPSIS
.Fd #include
.Ft double
.Fn modf "double value" "double *iptr"
.Ft long double
.Fn modfl "long double value" "long double *iptr"
.Ft float
.Fn modff "float value" "float *iptr"
.Sh DESCRIPTION
The
.Fn modf
break
.Fa value
into integral and fractional parts, each of which has the same sign as the argument.
They return the fractional part, and store the integral part (as a floating-point number)
in the object pointed to by
.Fa iptr
.Sh SPECIAL VALUES
.Fn modf "±infinity" "iptr"
returns ±0 and stores ±infinity in the object pointed to by iptr.
.Pp
.Fn modf "NaN" "iptr"
returns a NaN and stores a NaN in the object pointed to by iptr.
.Sh SEE ALSO
.Xr frexp 3 ,
.Xr ldexp 3 ,
.Xr math 3
.Sh STANDARDS
The
.Fn modf
functions conform to ISO/IEC 9899:1999(E).