xref: /csrg-svn/lib/libc/gen/frexp.3 (revision 50301)
148352Scael.\" Copyright (c) 1991 The Regents of the University of California.
248352Scael.\" All rights reserved.
320316Smckusick.\"
4*50301Sbostic.\" This code is derived from software contributed to Berkeley by
5*50301Sbostic.\" the American National Standards Committee X3, on Information
6*50301Sbostic.\" Processing Systems.
7*50301Sbostic.\"
848352Scael.\" %sccs.include.redist.man%
948352Scael.\"
10*50301Sbostic.\"     @(#)frexp.3	6.5 (Berkeley) 06/29/91
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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