xref: /csrg-svn/lib/libc/gen/frexp.3 (revision 61111)
1*61111Sbostic.\" Copyright (c) 1991, 1993
2*61111Sbostic.\"	The Regents of the University of California.  All rights reserved.
320316Smckusick.\"
450301Sbostic.\" This code is derived from software contributed to Berkeley by
550301Sbostic.\" the American National Standards Committee X3, on Information
650301Sbostic.\" Processing Systems.
750301Sbostic.\"
848352Scael.\" %sccs.include.redist.man%
948352Scael.\"
10*61111Sbostic.\"     @(#)frexp.3	8.1 (Berkeley) 06/04/93
1148352Scael.\"
1248352Scael.Dd
1348352Scael.Dt FREXP 3
1448352Scael.Os
1548352Scael.Sh NAME
1648352Scael.Nm frexp
1748352Scael.Nd convert floating-point number to fractional and integral components
1848352Scael.Sh SYNOPSIS
1948352Scael.Fd #include <math.h>
2048352Scael.Ft double
2148352Scael.Fn frexp "double value" "int *exp"
2248352Scael.Sh DESCRIPTION
2348352ScaelThe
2448352Scael.Fn frexp
2548352Scaelfunction breaks a floating-point number into a normalized
2648352Scaelfraction and an integral power of 2.
2748352ScaelIt stores the integer in the
2848352Scael.Em int
2948352Scaelobject pointed to by
3048352Scael.Fa exp .
3148352Scael.Sh RETURN VALUES
3248352ScaelThe
3348352Scael.Fn frexp
3448352Scaelfunction returns the value
3548352Scael.Em x ,
3648352Scaelsuch that
3748352Scael.Em x
3848352Scaelis a
3948352Scael.Em double
4048352Scaelwith magnitude in the interval
4148352Scael.Bq 1/2 , 1
4248352Scaelor zero, and
4348352Scael.Fa value
4448352Scaelequals
4548352Scael.Em x
4648352Scaeltimes 2 raised to the power
4748352Scael.Fa *exp .
4848352ScaelIf
4948352Scael.Fa value
5048352Scaelis zero, both parts of the result are zero.
5148352Scael.Sh SEE ALSO
5248352Scael.Xr ldexp 3 ,
5348352Scael.Xr modf 3 ,
5448352Scael.Xr math 3
5548352Scael.Sh STANDARDS
5648352ScaelThe
5748352Scael.Fn frexp
5848352Scaelfunction conforms to
5948352Scael.St -ansiC .
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