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.\" from: @(#)floor.3 6.5 (Berkeley) 4/19/91
.\" $Id: modf.3,v 1.4 2004/12/20 21:35:46 scp Exp $
.\"
.Dd December 11, 2006
.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).