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.\" Copyright 2004 Andries Brouwer <aeb@cwi.nl>.
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date. The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein. The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.\" Inspired by a page by Walter Harms created 2002-08-10
.\"
.\" Japanese Version Copyright (c) 2005 Yuichi SATO
.\" all rights reserved.
.\" Translated Sat Jan 29 06:47:42 JST 2005
.\" by Yuichi SATO <ysato444@yahoo.co.jp>
.\"
.TH LOGB 3 2004-10-31 "" "Linux Programmer's Manual"
.SH ̾
logb, logbf, logbl \- ưλؿ
.SH
.B #include <math.h>
.sp
.BI "double logb(double " x );
.br
.BI "float logbf(float " x );
.br
.BI "long double logbl(long double " x );
.sp
\-lm ǥ롣
.SH
δؿ
.I x
λؿФưȤ֤
.B FLT_RADIX
2 ξ硢
.BI logb( x )
.BI floor(log2( x ))\fR
Ԥ֤®Ǥ롣
.LP
.I x
Ƥʤ硢
.B logb()
.I x
줿λؿ֤
.LP
.I x
0 ξ硢-HUGE_VAL, -HUGE_VALF, -HUGE_VALL 줾֤ơ
(pole) ˤ륨顼롣
.I x
̵ξ硢̵礬֤롣
.I x
NaN ξ硢NaN ֤롣
.\" .SH ֤
.\" δؿϰλؿ֤
.SH 顼
顼å뤿ˤϡδؿƤӽФ
.I errno
0 ꤷ
.I feclearexcept(FE_ALL_EXCEPT)
ƤӽФ
δؿ֤äǡ
.I errno
0 ʳޤ
.I fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW)
0 ʳˤʤäƤϡ顼Ƥ롣
.LP
顼Ƥơ
.I "(math_errhandling & MATH_ERRNO)"
0 ʳξ硢
.I errno
.B ERANGE
ꤵ롣
顼Ƥơ
.I "(math_errhandling & MATH_ERREXCEPT)"
0 ʳξ硢0 dzäȤˤư㳰ȯ롣
.LP
.I x
0 ξ硢ˤˤ륨顼롣
.SH
.B logb
ؿ BSD 4.3 Ƴ줿
.\" BSD 4.3 ޥ˥奢 IEEE.3 Ȥ뤳ȡ
.SH
ISO C99
.SH Ϣ
.BR log (3),
.BR ilogb (3)
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